摘要
环境保护是人类在21世纪的最重大课题之一。塑料材料和合成纤维的大量使用,在自然环境中造成严重的“白色污染”。自上世纪80年代,人们开始研究和开发生物可降解聚合物及其制品来取代传统塑料,以减少环境污染。
聚乳酸(PLA)是目前最为研究者关注的可降解聚合物材料之一。聚乳酸也称为聚丙交酯,是一种真正的新型绿色材料,其原料乳酸来源充分而且可以再生。聚乳酸不仅可以生物降解,而且生产过程无污染,可用多种方式进行加工,如挤压、纺丝、双轴拉伸,注射吹塑。产品具有良好的生物相容性、光泽度、透明性、手感,还具有一定的耐菌性、阻燃性和抗紫外性,因此用途十分广泛,可用作包装材料、纤维和非织造物等。在应用性能方面,PLA存在着脆性大,抗冲击性也较差的缺点。实验证明,借助共聚合技术对PLA进行改性,不仅可显著改善了PLA的缺陷,且易对材料降解性能实现调控,对降低产品成本也有显著的效果。本论文分别采用国产新型低不饱和度聚环氧丙烷(PPO)和ε-己内酯(ε-CL),与PLA共聚制备了系列三枝化嵌段或无规共聚物。实现以柔性的PPO链段和CL链段对PLA链段的凝聚态调控的分子设计,并开发了系列新型环境友好可降解聚氨酯材料,包括PPO-左旋聚乳酸(PLLA)基和PPO-外消旋聚乳酸(PDLLA)基部分可降解聚醚-聚酯型聚氨酯泡沫材料、PPO-PLLA基全降解聚醚-聚酯型聚氨酯泡沫材料和全降解型的PLLA-PCL基聚酯聚氨酯泡沫材料等,对聚氨酯泡沫材料的开发进行了创新性的研究。论文的主要研究内容如下:
(1)采用红外(FTIR)、凝胶渗透色谱(GPC)、基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)、氢核磁谱(~1H-NMR)、碳核磁谱(~(13)C-NMR)对双金属氰化物混合物催化剂、连续法合成的国产新型低不饱和度聚醚多元醇的化学结构及组成等进行了详细的分析。在与通用聚醚多醇对比实验的基础上,揭示了低不饱和度聚醚多元醇的分子结构特点。通过差示扫描量热仪(DSC)和热失重分析(TGA)对聚醚多元醇的热性能进行了测试。为新材料的制备奠定了基础。
(2)探索了以低不饱和度聚醚多元醇为原料,采用“一步法”以水为发泡剂合成软质聚氨酯泡沫的技术,解决了低不饱和度聚醚多元醇在发泡过程中易产生塌泡的问题。通过衰减全反射傅立叶变换红外光谱(ATR-FTIR)和DSC揭示了软质聚氨酯泡沫内部的微相形貌,结果表明聚氨酯内部既存在硬相氨酯或脲与软相聚醚之间的微相混合也存在微相分离,并以微相混合为主,微相分离程度较低。力学测试结果表明,低不饱和度聚醚软质聚氨酯泡沫在撕裂、压缩等性能上均好于通用聚醚软质聚氨酯泡沫。
(3)以低不饱和度PPO三元醇为大分子引发剂,在辛酸亚锡的催化作用下,通过L-丙交酯或DL-丙交酯进行配位-插入开环聚合合成了PO与LA不同单体摩尔比和凝聚态的三枝化低不饱和度PPO-b-PLA嵌段共聚物。通过FTIR、GPC、~1H-NMR对PPO-b-PLA嵌段共聚物的化学结构和链组成等进行了详实的表征。研究结果表明PPO-b-PLA嵌段共聚物的分子量分布极窄,多分散系数(PDI)在1.0~1.1之间,其化学结构和链组成与分子实验设计基本一致。DSC和广角X射线衍射(WAXD)对PPO-b-PLA嵌段共聚物的凝聚态进行了研究。由于PLLA链段为等规立构构型,PPO-b-PLLA中的PLLA链段具有结晶能力,其结晶度随PLLA链段长度的降低而降低。由于PDLLA为无规立构构型,因此,PPO-b-PDLLA嵌段共聚物为无定形聚合物。TGA对PPO-b-PLA嵌段共聚物的热稳定性测试结果表明PLLA和PDLLA链段使嵌段共聚物的热稳定性得到了提高,其中立够规整度好的PLLA链段对共聚物热稳定性的提高贡献更大。
(4)分别制备了基于三枝化低不饱和度PPO-b-PLA嵌段共聚物的从部分降解到全降解的新型聚氨酯泡沫材料。采用ATR-FTIR和DSC对PPO-b-PLA基聚氨酯泡沫的微相形貌进行了表征,研究证明了PLA链段的引入促进了聚氨酯内部的微相混合,并且PDLLA链段比PLLA链段对微相混合的贡献更大。另外,全降解PPO-b-PLA基聚氨酯泡沫内部的微相混合程度高于部分降解PPO-b-PLA基聚氨酯泡沫。通过AFM对聚氨酯的微相形貌观察结果显示纯的聚醚聚氨酯内部发生了微相分离;PPO-b-PLLA基部分降解聚氨酯泡沫中,等规立构的PLLA链段发生了微相分离,但没有观察到硬段氨酯或脲的微相分离;PPO-b-PDLLA基部分降解聚氨酯泡沫中,没有发生微相分离现象。
PPO-b-PLA基部分降解聚氨酯泡沫在力学性能方面表现出了较高的撕裂和拉伸性能,并且PPO-b-PDLLA基部分降解聚氨酯泡沫无论在撕裂、拉伸、回弹性能上均好于PPO-b-PLLA基部分降解聚氨酯泡沫。碱催化水解实验证明PPO-b-PLA基聚氨酯泡沫的降解能力随PLA的含量增加而增加,且基于无规立构的PDLLA链段的聚氨酯泡沫的水解性好于基于等规立构的PLLA链段的聚氨酯泡沫。PPO-b-PLA基全降解聚氨酯泡沫的碱催化水解的速率和程度远高于PPO-b-PLA基部分降解聚氨酯泡沫。酶解实验证明,PPO-b-PLA基全降解聚氨酯泡沫具有酶降解能力;而PPO-b-PLA基部分降解聚氨酯泡沫的酶降解行为不明显。
(5)以丙三醇为引发剂,辛酸亚锡为催化剂,通过丙交酯和ε-己内酯开环聚合反应合成了一系列分子量为3000左右,不同单体摩尔比的三枝化PLLA-r-PCL无规共聚物。通过FTIR、GPC和~1H-NMR对共聚物的化学结构和链组成进行了表征,结果表明PLLA-r-PCL为无规共聚结构,其化学结构和分子组成与实验设计基本一致。并以三枝化PLLA-r-PCL无规共聚物为原料合成了聚酯型全降解聚氨酯泡沫。ATR-FTIR和DSC证明了PLLA-r-PCL基聚氨酯泡沫中既存在微相分离又存在微相混合,且微相混合的程度远高于微相分离的程度。PLLA-r-PCL基聚氨酯泡沫在力学性能上表现为硬度较高的材料。碱催化水解和酶降解实验表明,PLLA-r-PCL基聚氨酯泡沫表现出了良好的降解能力。
Environmental protection is one of the tasks of vital importance in the 21st century.The huge consumption of plastics and synthetic fibres has caused serious "white pollution" problems in the natural environment.Since 1980s,with the aim of reducing environmental pollution,people have started to develop biodegradable polymers and products as a substitute for general plastics.
Poly(lactic acid)(PLA) has been one of the degradable polymers that attract the most attention of researchers.Poly(lactic acid),also called polylactide,is an essentially novel green material because of the sufficient and renewable resources of lactic acid.In addition,PLA is biodegradable and its producing procedure is pollution free.PLA can be processed by many methods,such as extrusion,spinning,biaxially oriented,injection and blow molding.PLA products have good biocompatibility, brightness,clarity,touch feeling,and also reasonable fungus resistance,flame resistance,and anti-UV properties.Therefore,PLA products are widely used as packaging materials,fibres,and bonded yarn fabrics.However,PLA is brittle and of low impact resistance.Experiments show that the defects can be modified by copolymerizing PLA with other materials,and variable degradability and lower production costs can also be realized.In this work,triarm block or random copolymers were synthesized from domestic novel low unsaturated poly(propylene oxide)(PPO) orε-caprolactone(CL) together with PLA.The condensed matter of PLA segments is adjusted by the soft PPO or PCL segments.Furthermore,novel environmental friendly degradable polyurethane(PU) materials were investigated, including PPO-b-PLLA or PPO-b-PDLLA based partially degradable PU foams, PPO-b-PLLA based fully degradable PU foams,and PLLA-r-PCL based fully degradable PU foams.The main contents of this work are as follows.
(1) Fourier transform infrared(FTIR),gel permeation chromatography(GPC), matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS),proton nuclear magnetic resonance(~1H-NMR),and ~(13)C nuclear magnetic resonance(~(13)C-NMR) were carried out to investigate the chemical structure and composition of the domestic novel low unsaturated polyether polyols,which were synthesized by continuous process using double metal cyanide complex catalysts.The molecular structure of low unsaturated polyether polyols were characterized and compared with the general polyether polyols.Differential scanning calorimetry(DSC) and thermogravimetric analysis(TGA) were measured to evaluate the thermal properties of the polyether polyols.Basic data were provided for further developing of new materials.
(2) The synthesis of flexible PU foams from low unsaturated polyether polyols by one-stage process using water as blowing agent were investigated.The processing technic was found to be a good solution to the problem of collapse during the foam forming process from low unsaturated polyether polyols.The microphase morphology of flexible PU foams were investigated by attenuated total reflectance(ATR)-FTIR and DSC.The results show that both microphase mixing and microphase separation between the hard segments of urethane or urea and the soft segments of polyether present in flexible PU foams,while the microphase mixing is dominating.The mechanical tests show that both the tear propagation resistance and compression hardness of flexible PU foams made from low unsaturated polyether polyols are better than those of general flexible PU foams.
(3) Triarm low unsaturated PPO-b-PLA copolymers of different PO/LA molar ratios and condensed matter were synthesized by ring-opening polymerization of L-lactide or DL-lactide using low unsaturated PPO triols as macromolecular initiator and stannous octoate as catalyst.FTIR,GPC,and ~1H-NMR were used to investigate the chemical structure and chain composition.It is proved that the copolymers all present narrow molecular weight distribution(PDI~1.0-1.1).It was shown by DSC and wide angle X-ray diffraction(WAXD) that PPO-b-PLLA copolymers with isotactic PLLA segments are crystalline materials,and the crystallinity decreases with decreasing the PLLA segments length,whereas,PPO-b-PDLLA copolymers having atactic PDLLA segments are amorphous.The thermal stability of PPO-b-PLA copolymers was improved by introducing PLLA or PDLLA segments according to the results of TGA experiments,and PLLA segments were found to have a stronger effect than PDLLA segments.
(4) PPO-b-PLA based partially degradable and fully degradable PU foams were synthesized.It was found by ATR-FTIR and DSC that the PLA segments improve the microphase mixing in PPO-b-PLA based PU foams.In addition,the contribution of PDLLA segments to the microphase mixing is greater than that of PLLA segments. The extent of microphase mixing in PPO-b-PLLA based fully degradable PU foams is greater than that in PPO-b-PLA based partially degradable PU foams.Atomic force microscope(AFM) was also used to examine the microphase morphology of PU foams.The results show that microphase separation of urethane or urea takes place in pure PPO foams.As for PPO-b-PLLA based partially degradable PU foams, microphase separation of PLLA segments is observed besides that of urethane or urea. No microphase separation is observed in PPO-b-PDLLA based partially degradable PU foams.
The mechanical property tests show that PPO-b-PLA based partially degradable PU foams exhibit high performance in both tear propagation resistance and tensile properties.The tear propagation resistance,tensile,and rebound resilience properties of PPO-b-PDLLA based partially degradable PU foams are better than those of PPO-b-PLLA based partially degradable PU foams.Alkaline hydrolysis experiments prove that the degradability of PPO-b-PLA based PU foams increases with increasing PLA content,and the degradability of PPO-b-PDLLA based partially degradable PU foams is greater than that of PPO-b-PLLA based partially degradable PU foams.And the degradation rate and extent of PPO-b-PLA based fully degradable PU foams are far greater than those of PPO-b-PLA based partially degradable PU foams under alkaline hydrolysis condition.In contrast,pure PPO foams are non-degradable under the alkaline hydrolysis condition.Enzymatic degradations prove that PPO-b-PLA based fully degradable PU foams are degradable under enzymatic degradation condition,whereas the degradation behaviors of PPO-b-PLA based partially degradable PU foams are not obvious.
(5) Triarm PLLA-r-PCL random copolymers with various monomer molar ratios were synthesized by ring-opening polymerization of L-lactide andε-CL using glycerol as initiator and stannous octoate as catalyst.FTIR,GPC,and ~1H-NMR were used to investigate the chemical structure and chain composition.It is confirmed that the copolymers are random copolymers,and the chemical structure and the chain composition of the copolymers are as expected as the initial molecular design.In addition,PLLA-r-PCL based fully degradable PU foams were synthesized from PLLA-r-PCL copolymers.It is found by ATR-FTIR and DSC that a slight microphase separation exists in this material.The mechanical property tests show that PLLA-r-PCL based PU foams exhibit high hardness.Moreover,PLLA-r-PCL based PU foams exhibit great degradability under both alkaline hydrolysis and enzymatic degradation condition.
引文
[1]Sinclair RG.The case for polylactic acid as a commodity packaging plastic[J].J Macromol Sci-Pure Appl Chem,1996,A33(5):585-97.
[2]Anon.Future looks promising for biodegradable plastics[J].Biocycle,1999,40(8):8-.
[3]戈进杰 徐,张志楠.基于天然聚多糖的环境友好材料(Ⅱ)-麻纤维和芦苇纤维多元醇的生物降解聚氨酯[J].化学学报,2002,60(4):732-6.
[4]Nagahama K,Nishimura Y,Ohya Y,et al.Impacts of stereoregularity and stereocomplex formation on physicochemical,protein adsorption and cell adhesion behaviors of star-shaped 8-arms poly(ethylene glycol)-poly(lactide) block copolymer films[J].Polymer,2007,48(9):2649-58.
[5]Lemmouchi Y,Perry MC,Amass AJ,et al.Novel synthesis of biodegradable star poly(ethylene glycol)-block-poly(lactide) copolymers[J].J Polym Sci Pol Chem, 2007,45(17): 3966-74.
[6] Stefani M, Coudane J, Vert M. In vitro ageing and degradation of PEG - PLA diblock copolymer-based nanoparticles [J]. Polym Degrad Stabil, 2006, 91(11):2554-9.
[7] Kulinski Z, Piorkowska E, Gadzinowska K, et al. Plasticization of poly(L-lactide) with poly(propylene glycol) [J]. Biomacromolecules, 2006, 7(7): 2128-35.
[8] Piorkowska E, Kulinski Z, Galeski A, et al. Plasticization of semicrystalline poly(L-lactide) with polypropylene glycol) [J]. Polymer, 2006, 47(20): 7178-88.
[9] Vert M, Li SM, Spenlehauer G, et al. Bioresorbability and Biocompatibility of Aliphatic Polyesters [J]. J Mater Sci-Mater Med, 1992, 3(6): 432-46.
[10]Drumright RE, Gruber PR, Henton DE. Polylactic acid technology [J]. Adv Mater,2000, 12(23): 1841-6.
[11] Chandra R, Rustgi R. Biodegradable polymers [J]. Prog Polym Sci, 1998, 23(7):1273-335.
[12]Privalova LG, Zaikov GE. Polymers in Surgery - Problems and Prospects [J].Polym-Plast Technol Eng, 1990, 29(5-6): 455-520.
[13] Thomson RC, Wake MC, Yaszemski MJ, et al. Biodegradable polymer scaffolds to regenerate organs [M]. Biopolymers Ii. Berlin 33; Springer-Verlag Berlin. 1995:245-74.
[14]Hoogsteen W, Postema AR, Pennings AJ, et al. Crystal-Structure, Conformation, and Morphology of Solution-Spun Poly(L-Lactide) Fibers [J]. Macromolecules, 1990,23(2): 634-42.
[15]Fambri L, Pegoretti A, Fenner R, et al. Biodegradable fibres of poly(L-lactic acid) produced by melt spinning [J]. Polymer, 1997, 38(1): 79-85.
[16]Garlotta D. A literature review of poly(lactic acid) [J]. J Polym Environ, 2001,9(2): 63-84.
[17]Sarasua JR, Prud'homme RE, Wisniewski M, et al. Crystallization and melting behavior of polylactides [J]. Macromolecules, 1998, 31(12): 3895-905.
[18]Baratian S, Hall ES, Lin JS, et al. Crystalization and solid-state structure of random polylactide copolymers: Poly(L-lactide-co-D-lactide)s [J]. Macromolecules,2001, 34(14): 4857-64.
[19] Sasaki S, Asakura T. Helix distortion and crystal structure of the alpha-form of poly(L-lactide) [J]. Macromolecules, 2003, 36(22): 8385-90.
[20]Cartier L, Okihara T, Ikada Y, et al. Epitaxial crystallization and crystalline polymorphism of polylactides [J]. Polymer, 2000, 41(25): 8909-19.
[21]Kolstad JJ. Crystallization kinetics of poly(L-lactide-co-meso-lactide) [J]. J Appl Polym Sci, 1996, 62(7): 1079-91.
[22]Ajioka M, Enomoto K, Suzuki K, et al. Basic Properties of Polylactic Acid Produced by the Direct Condensation Polymerization of Lactic-Acid [J]. Bull Chem SocJpn, 1995, 68(8): 2125-31.
[23]Ajioka M, Suizu H, Higuchi C, et al. Aliphatic polyesters and their copolymers synthesized through direct condensation polymerization [J]. Polym Degrad Stabil,1998, 59(1-3): 137-43.
[24] Gupta AP, Kumar V. New emerging trends in synthetic biodegradable polymers -Polylactide: A critique [J]. Eur Polym J, 2007, 43(10): 4053-74.
[25]Shyamroy S, Garnaik B, Sivaram S. Structure of poly(L-lactic acid)s prepared by the dehydropolycondensation of L-lactic acid with organotin catalysts [J]. J Polym Sci Pol Chem, 2005, 43(10): 2164-77.
[26] Takasu A, Narukawa Y, Hirabayashi T. Direct dehydration polycondensation of lactic acid catalyzed by water-stable Lewis acids [J]. J Polym Sci Pol Chem, 2006,44(18): 5247-53.
[27]Moon SI, Lee CW, Taniguchi I, et al. Melt/solid polycondensation of L-lactic acid: an alternative route to poly(L-lactic acid) with high molecular weight [J]. Polymer,2001, 42(11): 5059-62.
[28] Moon SI, Taniguchi I, Miyamoto M, et al. Synthesis and properties of high-molecular-weight poly(L-lactic acid) by melt/solid polycondensation under different reaction conditions [J]. High Perform Polym, 2001, 13(2): S189-S96.
[29] Zhang XC, Macdonald DA, Goosen MFA, et al. Mechanism of Lactide Polymerization in the Presence of Stannous Octoate - the Effect of Hydroxy and Carboxylic-Acid Substances [J]. J Polym Sci Pol Chem, 1994, 32(15): 2965-70.
[30]Kricheldorf HR. Syntheses and application of polylactides [J]. Chemosphere,2001, 43(1): 49-54.
[31]Kricheldorf HR, Kreisersaunders I. Polylactones .19. Anionic-Polymerization of L-Lactide in Solution [J]. Makromolekulare Chemie-Macromolecular Chemistry and Physics, 1990, 191(5): 1057-66.
[32] Tang ZH, Chen XS, Hang QZ, et al. Strontium-based initiator system for ring-opening polymerization of cyclic esters [J]. J Polym Sci Pol Chem, 2003, 41(13):1934-41.
[33]Kricheldorf HR, Dunsing R. Polylactones .8. Mechanism of the Cationic Polymerization of L,L-Dilactide [J]. Makromolekulare Chemie-Macromolecular Chemistry and Physics, 1986, 187(7): 1611-25.
[34] Wang CH, Li H, Zhao X. Ring opening polymerization of L-lactide initiated by creatinine [J]. Biomaterials, 2004, 25(27): 5797-801.
[35] Stolt M, Sodergard A. Use of monocarboxylic iron derivatives in the ring-opening polymerization of L-lactide [J]. Macromolecules, 1999, 32(20): 6412-7.
[36] Sunder A, Mulhaupt R, Frey H. Hyperbranched polyether-polyols based on polyglycerol: Polarity design by block copolymerization with propylene oxide [J].Macromolecules, 2000, 33(2): 309-14.
[37] Sunder A, Bauer T, Mulhaupt R, et al. Synthesis and thermal behavior of esterified aliphatic hyperbranched polyether polyols [J]. Macromolecules, 2000, 33(4):1330-7.
[38]Chisholm MH, Navarro-Llobet D, Simonsick WJ. A comparative study in the ring-opening polymerization of lactides and propylene oxide [J]. Macromolecules,2001, 34(26): 8851-7.
[39]Aubrecht KB, Grubbs RB. Synthesis and characterization of thermo responsive ampbiphilic block copolymers incorporating a poly(ethylene oxide-stat-propyleneoxide) block [J]. J Polym Sci Pol Chem, 2005, 43(21): 5156-67.
[40] Pitt CG, Gratzl MM, Kimmel GL, et al. Aliphatic Polyesters .2. the Degradation of Poly(Dl-Lactide), Poly(Epsilon-Caprolactone), and Their Copolymers Invivo [J].Biomaterials, 1981, 2(4): 215-20.
[41]Sawhney AS, Hubbell JA. Rapidly Degraded Terpolymers of DL-Lactide, Glycolide, and Epsilon-Caprolactone with Increased Hydrophilicity by Copolymerization with Polyethers [J]. J Biomed Mater Res, 1990, 24(10): 1397-411.
[42]Fukuzaki H, Yoshida M, Asano M, et al. Synthesis of Low-Molecular-Weight Copoly(L-Lactic Acid Epsilon-Caprolactone) by Direct Copolycondensation in the Absence of Catalysts, and Enzymatic Degradation of the Polymers [J]. Polymer, 1990,31(10): 2006-14.
[43]Perego G, Vercellio T, Balbontin G. Copolymers of L-Lactide and D,L-Lactide with 6-Caprolactone - Synthesis and Characterization [J]. Makromolekulare Chemie-Macromolecular Chemistry and Physics, 1993, 194(9): 2463-9.
[44] Zhang XC, Wyss UP, Pichora D, et al. Biodegradable Polymers for Orthopedic Applications - Synthesis and Processability of Poly(L-Lactide) and Poly(Lactide-Co-Epsilon-Caprolactone) [J]. J Macromol Sci-Pure Appl Chem, 1993,A30(12): 933-47.
[45]Grijpma DW, Vanhofslot RDA, Super H, et al. Rubber Toughening of Poly(Lactide) by Blending and Block Copolymerization [J]. Polym Eng Sci, 1994,34(22): 1674-84.
[46]Kricheldorf HR, Kreiser I. Polylactones .13. Trans-Esterification of Poly(L-Lactide) with Poly(Glycolide), Poly(Beta-Propiolactone), and Poly(Epsilon-Caprolactone) [J]. Journal of Macromolecular Science-Chemistry, 1987,A24(11): 1345-56.
[47] Kasperczyk J, Bero M. Coordination Polymerization of Lactides .4. the Role of Transesterification in the Copolymerization of L,L-Lactide and Epsilon-Caprolactone [J]. Makromolekulare Chemie-Macromolecular Chemistry and Physics, 1993, 194(3):913-25.
[48]Jabbari E, He XZ, Valarmathi MT, et al. Material properties and bone marrow stromal cells response to in situ crosslinkable RGD-functionlized lactide-co-glycolide scaffolds [J]. J Biomed Mater Res Part A, 2009, 89A(1): 124-37.
[49] Stevanovic M, Uskokovic D. Poly(lactide-co-glycolide)-based Micro and Nanoparticles for the Controlled Drug Delivery of Vitamins [J]. Curr Nanosci, 2009,5(1): 1-14.
[50] Wu T, He Y, Fan ZY, et al. Investigations on the morphology and melt crystallization of poly(L-lactide)-poly(ethylene glycol) diblock copolymers [J]. Polym Eng Sci, 2008, 48(3): 425-33.
[51]Edlund U, Albertsson AC. Degradable polymer microspheres for controlled drug delivery [M]. Degradable Aliphatic Polyesters. Berlin; Springer-Verlag Berlin. 2002,157:67-112.
[52] Reeve MS, McCarthy SP, Downey MJ, et al. Polylactide Stereochemistry - Effect on Enzymatic Degradability [J]. Macromolecules, 1994, 27(3): 825-31.
[53]Li SM, Tenon M, Garreau H, et al. Enzymatic degradation of stereocopolymers derived from L-, DL- and meso-lactides [J]. Polym Degrad Stabil, 2000, 67(1): 85-90.
[54]Ouhadi T, Hamitou A, Jerome R, et al. Soluble Bimetallic Mu-Oxo-Alkoxides .8.Structure and Kinetic-Behavior of Catalytic Species in Unsubstituted Lactone Ring-Opening Polymerization [J]. Macromolecules, 1976, 9(6): 927-31.
[55]Jacobsen S, Degee PH, Fritz HG, et al. Polylactide (PLA) - A new way of production [J]. Polym Eng Sci, 1999, 39(7): 1311-9.
[56]Schindler A,Hibionada YM,Pitt CG.Aliphatic Polyesters.3.Molecular-Weight and Molecular-Weight Distribution in Alcohol-Initiated Polymerizations of Epsilon-Caprolactone[J].J Polym Sci Pol Chem,1982,20(2):319-26.
[57]Kohn FE,Vanommen JG,Feijen J.The Mechanism of the Ring-Opening Polymerization of Lactide and Glycolide[J].Eur Polym J,1983,19(12):1081-8.
[58]Kowalski A,Libiszowski J;Duda A,et al.Polymerization of L,L-dilactide initiated by tin(Ⅱ) butoxide[J].Macromolecules,2000,33(6):1964-71.
[59]Storey RF,Taylor AE.Effect of stannous octoate on the composition,molecular weight,and molecular weight distribution of ethylene glycol-initiated poly(epsilon-caprolaccone)[J].J Macromol Sci-Pure Appl Chem,1998,A35(5):723-50.
[60]Stevels WM,Ankone MJK,Dijkstra PJ,et al.Kinetics and mechanism of epsilon-caprolactone polymerization using yttrium alkoxides as initiators[J].Macromolecules,1996,29(26):8296-303.
[61]Lee SH,Kim BS,Kim SH,et al.Elastic biodegradable poly(glycolide-co-caprolactone) scaffold for tissue engineering[J].J Biomed Mater Res Part A,2003,66A(1):29-37.
[62]Nozirov F,Szczesniak E,Fojud Z,et al.H-1 and C-13 NMR studies of molecular dynamics in the biocopolymer of glycolide and epsilon-caprolactone[J].Solid State Nucl Magn Reson,2002,22(1):19-28.
[63]Cho DK,Park JW,Kim SH,et al.Effect of molecular orientation on biodegradability of poly(glycolide-co-epsilon-caprolactone)[J].Polym Degrad Stabil,2003,80(2):223-32.
[64]Deng XM,Yuan ML,Xiong CD,et al.Polymerization of lactides and lactones.Ⅱ.Ring-opening polymerization of epsilon-caprolactone and DL-lactide by organoacid rare earth compounds[J].J Appl Polym Sci,1999,71(12):1941-8.
[65]Chamberlain BM,Jazdzewski BA,Pink M,et al.Controlled polymerization of DL-lactide and epsilon-caprolactone by structurally well-defined alkoxo-bridged diand triyttrium(Ⅲ) complexes[J].Macromolecules,2000,33(11):3970-7.
[66]Shiomi T,Imai K,Takenaka K,et al.Appearance of double spherulites like concentric circles for poly(epsilon-caprolactone)-block-poly(ethylene glycol)-block -poly(epsilon-caprolactone)[J].Polymer,2001,42(7):3233-9.
[67]Bei JZ,He WS,Hu XZ,et al.Photodegradation behavior and mechanism of block copoly(caprolactone-ethylene glycol)[J].Polym Degrad Stabil,2000,67(2): 375-80.
[68]Jeong JH,Kang HS,Yang SR,et al.Polymer micelle-like aggregates of novel amphiphilic biodegradable poly(asparagine) grafted with poly(caprolactone)[J].Polymer,2003,44(3):583-91.
[69]Degee P,Dubois P,Jerome R,et al.Synthesis and Characterization of Biocompatible and Biodegradable Poly(Epsilon-Caprolactone-B-Gamma-Benzylglutamate)Diblock Copolymers[J].J Polym Sci Pol Chem,1993,31(1):275-8.
[70]Li MX,Zhuo RX,Qu FQ.Synthesis and characterization of novel biodegradable poly(ester amide) with ether linkage in the backbone chain[J].J Polym Sci Pol Chem,2002,40(24):4550-5.
[71]Qian ZY,Li S,He Y,et al.Synthesis and thermal degradation of biodegradable polyesteramide based on epsilon-caprolactone and 11-aminoundecanoic acid[J].Polym Degrad Stabil,2003,81(2):279-86.
[72]Pitt CG,Chasalow FI,Hibionada YM,et al.Aliphatic Polyesters.1.the Degradation of Poly(Epsilon-Caprolactone) Invivo[J].J Appl Polym Sci,1981,26(11):3779-87.
[73]方禹声等.聚氨酯泡沫塑料[M].第二版.北京:化学工业出版社,1994.
[74]Coleman MM,Skrovanek DJ,Hu JB,et al.Hydrogen-Bonding in Polymer Blends.1.Ftir Studies of Urethane Ether Blends[J].Macromolecules,1988,21(1):59-65.
[75]Dounis DV,Wilkes GL.Structure-property relationships of flexible polyurethane foams[J].Polymer,1997,38(11):2819-28.
[76]Seymour RW,Cooper SL.Thermal-Analysis of Polyurethane Block Polymers[J].Macromolecules,1973,6(1):48-53.
[77]Swamy BKK,Siddaramaiah,Somashekarappa H,et al.Structure-property relationship in polyaniline-filled castor oil based chain extended polyurethanes[J].Polym Eng Sci,2004,44(4):772-8.
[78]Leung LM,Koberstein JT.Dsc Annealing Study of Microphase Separation and Multiple Endothermic Behavior in Polyether-Based Polyurethane Block Copolymers [J].Macromolecules,1986,19(3):706-13.
[79]Yilgor I,Yilgor E,Guler IG,et al.FTIR investigation of the influence of diisocyanate symmetry on the morphology development in model segmented polyurethanes[J].Polymer,2006,47(11):4105-14.
[80]Aneja A,Wilkes GL.Hard segment connectivity in low molecular weight model 'trisegment' polyurethanes based on monols[J].Polymer,2004,45(3):927-35.
[81]Elwell MJ,Ryan AJ,Grunbauer HJM,et al.An FT ir study of reaction kinetics and structure development in model flexible polyurethane foam systems[J].Polymer,1996,37(8):1353-61.
[82]Aneja A,Wilkes GL.On the issue of urea phase connectivity in formulations based on molded flexible polyurethane foams[J].J Appl Polym Sci,2002,85(14):2956-67.
[83]Elwell MJ,Ryan AJ,Grunbauer HJM,et al.Structure Development Via Ft-Ir Spectroscopy,Synchrotron Saxs and Rheology During the Reactive Processing of Flexible Polyurethane Foam[J].Plast Rubber Compos Process Appl,1995,23(4):265-76.
[84]Crawford DM,Bass RG,Haas TW.Strain effects on thermal transitions and mechanical properties of thermoplastic polyurethane elastomers[J].Thermochim Acta,1998,323(1-2):53-63.
[85]Chattopadhyay DK,Sreedhar B,Raju K.The phase mixing studies on moisture cured polyurethane-ureas during cure[J].Polymer,2006,47(11):3814-25.
[86]Romanova V,Begishev V,Karmanov V,et al.Fourier transform Raman and Fourier transform infrared spectra of cross-linked polyurethaneurea films synthesized from solutions[J].J Raman Spectrosc,2002,33(10):769-77.
[87]Pazos JF,Shih TT.Continuous preparation of low unsaturation polyoxyalkylene polyether polyols with continuous addition of starter[P].US 5689012,1997.
[88]宋虹霞,陈凤秋,顾良民,顾卫东,郑银才,邓爱华,周新华,徐文跃,蒋晓群.低不饱和度聚醚多元醇的制备方法[P].CN 1709939A,2005.
[89]涂建军,王荣伟,张惠明,金晖.低不饱和度聚醚多元醇的制备方法[P].CN 1566184A,2005.
[90]Cuscurida M.Process of preparing polyoxypropylene polyether polyols[P].US 3393243,1968.
[91]Heuvelsland AJ.Process for the preparation of polyether polyols with reduced unsaturation[P].US 5010187,1990.
[92]Olstowski F,Nafziger JL.Polyols[P].US 4282387,1981.
[93]Le-Khac B.Highly active double metal cyanide catalysts[P].US 5482908,1996.
[94]Le-Khac B.Double metal cyanide complex catalysts[P].US 5470813,1995.
[95]亢茂青,王心葵,殷宁,冯月兰,张清运,瞿波.一种软质聚氨酯泡沫塑料 的制备方法,[P].CN 1463997A,2003.
[96]Pazos JF,McDaniel KG.,Browne EP,et al.Double metal cyanide-catalyzed,low unsaturation polyethers from boron-containing starters[P].US 20070106097A1,2007.
[97]Tuinman R,Lee TB,Fishback TL,Reichel CJ.Use of low unsaturated polyether polyols in high resilience slabstock foam applications[P].US 6201035,2001.
[98]Harasin SJ,Roesler RR,Starcher RV,et al.Weather resistant polyurethane elastomer[P].US 20070142607A1,2007.
[99]Harasin SJ,Roesler RR,Starcher RV,et al.Polyurethane elastomers comprising allophanate modified isocyanates[P].US 20070142610A1,2007.
[100]Tuinman R,Fishback TL,Reichel CJ.Use of low unsaturated polyether polyols in slabstock foam applications[P].US 6344494,2002.
[101]李军,杨峻松,李静.低不饱和度聚醚多元醇制备聚氨酯弹性体[J].聚氨酯工业,2001,16(3):9-12.
[102]亢茂青,王心葵,殷宁,冯月兰,张清运,瞿波.一种软质聚氨酯泡沫塑料的制备方法,[P].CN 1463997A,2003.
[1]Lefebvre J,Bastin B,Le Bras M,et al.Thermal stability and fire properties of conventional flexible polyurethane foam formulations[J].Polym Degrad Stabil,2005,88(1):28-34.
[2]Lefebvre J,Bastin B,Le Bras M,et al.Flame spread of flexible polyurethane foam:comprehensive study[J].Polym Test,2004,23(3):281-90.
[3]Kaushiva BD,McCartney SR,Rossmy GR,et al.Surfactant level influences on structure and properties of flexible slabstock polyurethane foams[J].Polymer,2000,41(1):285-310.
[4]Pazos JF,Shih TT.Continuous preparation of low unsaturation polyoxyalkylene polyether polyols with continuous addition of starter[P].US 5689012,1997.
[5]宋虹霞,陈凤秋,顾良民,顾卫东,郑银才,邓爱华,周新华,徐文跃,蒋 晓群.低不饱和度聚醚多元醇的制备方法[P].CN 1709939A,2005.
[6]涂建军,王荣伟,张惠明,金晖.低不饱和度聚醚多元醇的制备方法[P].CN 1566184A,2005.
[7]Le-Khac B.Highly active double metal cyanide catalysts[P].US 5482908,1996.
[8].Le-Khac B.Double metal cyanide complex catalysts[P].US 5470813,1995.
[9]亢茂青,王心葵,殷宁,冯月兰,张清运,瞿波.一种软质聚氨酯泡沫塑料的制备方法,[P].CN 1463997A,2003.
[10]Pazos JF,McDaniel KG.,Browne EP,et al.Double metal cyanide-catalyzed,low unsaturation polyethers from boron-containing starters[P].US 20070106097A1,2007.
[11]Tuinman R,Lee TB,Fishback TL,Reichel CJ.Use of low unsaturated polyether polyols in high resilience slabstock foam applications[P].US 6201035,2001.
[12]Harasin SJ,Roesler RR,Starcher RV,et al.Weather resistant polyurethane elastomer[P].US 20070142607A1,2007.
[13]Harasin SJ,Roesler RR,Starcher RV,et al.Polyurethane elastomers comprising allophanate modified isocyanates[P].US 20070142610A1,2007.
[14]Tuinman R,Fishback TL,Reichel CJ.Use of low unsaturated polyether polyols in slabstock foam applications[P].US 6344494,2002.
[15]李军,杨峻松,李静.低不饱和度聚醚多元醇制备聚氨酯弹性体[J].聚氨酯工业,2001,16(3):9-12.
[16]亢茂青,王心葵,殷宁,冯月兰,张清运,瞿波.一种软质聚氨酯泡沫塑料的制备方法,[P].CN 1463997A,2003.
[17]吴瑾光.近代傅里叶变换红外光谱技术及应用[M].北京:科学技术文献出版社,1994.
[18]殷敬华,莫志深.现代高分子物理学[M].北京:科学出版社,2001.
[19]Heatley F,Luo YZ,Ding JF,et al.A C-13 Nuclear Magnetic-Resonance Study of the Triad Sequence Structure of Block and Statistical Copolymers of Ethylene-Oxide and Propylene-Oxide[J].Macromolecules,1988,21(9):2713-21.
[20]Oguni N,Shinohara S,Lee K.C-13 Nmr-Study of Poly(Propylene Oxide) and Poly(1-Butene Oxide)[J].Polymer Journal,1979,11(10):755-61.
[21]Sunder A,Mulhaupt R,Frey H.Hyperbranched polyether-polyols based on polyglycerol:Polarity design by block copolymerization with propylene oxide[J].Macromolecules,2000,33(2):309-14.
[22]Sunder A,Bauer T,Mulhaupt R,et al.Synthesis and thermal behavior of esterified aliphatie hyperbranched polyether polyols[J].Macromolecules,2000,33(4):1330-7.
[1]Bayer O.~*Das Di-Isocyanat-Polyadditionsverfahren(Polyurethane)[J].Angewandte Chemie,1947,59(9):257-72.
[2]Hepbum C.Polyurethane Elastomers[M].2nd ed.London:Elsevier Applied Science,1991.
[3]Herrington RH,K.Flexible Polyurethane Foams[M].2nd ed.Midland,MI:Dow Chemical Co.,1998.
[4]Elwell MJ,Ryan AJ,Grunbauer HJM,et al.An FT ir study of reaction kinetics and structure development in model flexible polyurethane foam systems[J].Polymer,1996,37(8):1353-61.
[5]Elwell MJ,Ryan AJ,Grunbauer HJM,et al.Structure Development Via Ft-Ir Spectroscopy,Synchrotron Saxs and Rheology During the Reactive Processing of Flexible Polyurethane Foam[J].Plast Rubber Compos Process Appl,1995,23(4):265-76.
[6]方禹声等.聚氨酯泡沫塑料[M].第二版.北京:化学工业出版社,1994.
[7]Pazos JF,Shih TT.Continuous preparation of low unsaturation polyoxyalkylene polyether polyols with continuous addition of starter[P].US 5689012,1997.
[8]宋虹霞,陈凤秋,顾良民,顾卫东,郑银才,邓爱华,周新华,徐文跃,蒋 晓群.低不饱和度聚醚多元醇的制备方法[P].CN 1709939A,2005.
[9]涂建军,王荣伟,张惠明,金晖.低不饱和度聚醚多元醇的制备方法[P].CN 1566184A,2005.
[10]Tuinman R,Lee TB,Fishback TL,Reichel CJ.Use of low unsaturated polyether polyols in high resilience slabstock foam applications[P].US 6201035,2001.
[11]Tuinman R,Fishback TL,Reichel CJ.Use of low unsaturated polyether polyols in slabstock foam applications[P].US 6344494,2002.
[12]亢茂青,王心葵,殷宁,冯月兰,张清运,瞿波.一种软质聚氨酯泡沫塑料的制备方法,[P].CN 1463997A,2003.
[13]马礼敦.高等结构分析[M].第二版.上海:复旦大学出版社,2002.
[14]Chattopadhyay DK,Sreedhar B,Raju K.The phase mixing studies on moisture cured polyurethane-ureas during cure[J].Polymer,2006,47(11):3814-25.
[15]Dounis DV,Wilkes GL.Structure-property relationships of flexible polyurethane foams[J].Polymer,1997,38(11):2819-28.
[16]Seymour RW,Cooper SL.Thermal-Analysis of Polyurethane Block Polymers [J].Macromolecules,1973,6(1):48-53.
[17]Swamy BKK,Siddaramaiah,Somashekarappa H,et al.Structure-property relationship in polyaniline-filled castor oil based chain extended polyurethanes[J].Polym Eng Sci,2004,44(4):772-8.
[18]Leung LM,Koberstein JT.Dsc Annealing Study of Microphase Separation and Multiple Endothermic Behavior in Polyether-Based Polyurethane Block Copolymers [J].Macromolecules,1986,19(3):706-13.
[19]Yilgor I,Yilgor E,Guler IG,et al.FTIR investigation of the influence of diisocyanate symmetry on the morphology development in model segmented polyurethanes[J].Polymer,2006,47(11):4105-14.
[20]Aneja A,Wilkes GL.Hard segment connectivity in low molecular weight model 'trisegment' polyurethanes based on monols[J].Polymer,2004,45(3):927-35.
[21]Aneja A,Wilkes GL.On the issue of urea phase connectivity in formulations based on molded flexible polyurethane foams[J].J Appl Polym Sci,2002,85(14):2956-67.
[22]Crawford DM,Bass RG,Haas TW.Strain effects on thermal transitions and mechanical properties of thermoplastic polyurethane elastomers[J].Thermochim Acta,1998,323(1-2):53-63.
[23]Coleman MM,Skrovanek DJ,Hu JB,et al.Hydrogen-Bonding in Polymer Blends.1.Ftir Studies of Urethane Ether Blends[J].Macromolecules,1988,21(1):59-65.
[24]Romanova V,Begishev V,Karmanov V,et al.Fourier transform Raman and Fourier transform infrared spectra of cross-linked polyurethaneurea films synthesized from solutions[J].J Raman Spectrosc,2002,33(10):769-77.
[25]Ren ZY,Ma DZ,Yang XZ.H-bond and conformations of donors and acceptors in model polyether based polyurethanes[J].Polymer,2003,44(20):6419-25.
[26]张俐娜,薛奇,莫志深,金熹高.高分子物理近代研究方法[M].第二版.武汉:武汉大学出版社,2006.
[27]Friedman HL.Kinetics of Thermal Degradation of Char-Forming Plastics from Thermogravimetry.Application to Phenolic Plastic[J].Journal of Polymer Science Part C-Polymer Symposium,1964,(6pc):183-95.
[28]Freeman ES,Carroll B.The Application of Thermoanalytical Techniques to Reaction Kinetics-the Thermogravimetric Evaluation of the Kinetics of the Decomposition of Calcium Oxalate Monohydrate[J].J Phys Chem,1958,62(4):394-7.
[29]Chang WL.Decomposition behavior of polyurethanes via mathematical simulation[J].J Appl Polym Sci,1994,53(13):1759-69.
[30]Flynn JH,Wall LA.A Quick Direct Method for Determination of Activation Energy from Thermogravimetric Data[J].Journal of Polymer Science Part B-Polymer Letters,1966,4(5PB):323.
[31]Chatterj.Pk,Conrad CM.Thermogravimetric Analysis of Cellulose[J].Journal of Polymer Science Part a-1-Polymer Chemistry,1968,6(12PA):3217.
[32]Horowitz HH,Metzger G.A New Analysis of Thermogravimetric Traces[J].Anal Chem,1963,35(10):1464.
[33]Kissinger HE.Reaction kinetics in differential thermal analysis[J].Analytical Chemistry,1957,29(11):1702-6.
[34]Coats AW,Redfern JP.Kinetic Parameters from Thermogravimetric Data[J].Nature,1964,201(491):68-9.
[35]Reich L.Rapid Estimation of Activation Energy from Thermogravimetric Traces [J].Journal of Polymer Science Part B-Polymer Letters,1964,2(6PB):621.
[36]Ozawa T.A New Method of Analyzing Thermogravimetric Data[J].Bull Chem Soc Jpn,1965,38(11):1881.
[1]Nagahama K,Nishimura Y,Ohya Y,et al.Impacts of stereoregularity and stereocomplex formation on physicochemical,protein adsorption and cell adhesion behaviors of star-shaped 8-arms poly(ethylene glycol)-poly(lactide) block copolymer films[J].Polymer,2007,48(9):2649-58.
[2]Lemmouchi Y,Perry MC,Amass AJ,et al.Novel synthesis of biodegradable star poly(ethylene glycol)-block-poly(lactide) copolymers[J].J Polym Sci Pol Chem,2007,45(17):3966-74.
[3]Stefani M,Coudane J,Vert M.In vitro ageing and degradation of PEG - PLA diblock copolymer-based nanoparticles[J].Polym Degrad Stabil,2006,91(11):2554-9.
[4]Shyamroy S,Garnaik B,Sivaram S.Structure of poly(L-lactic acid)s prepared by the dehydropolycondensation of L-lactic acid with organotin catalysts[J].J Polym Sci Pol Chem,2005,43(10):2164-77.
[5]Takasu A,Narukawa Y,Hirabayashi T.Direct dehydration polycondensation of lactic acid catalyzed by water-stable Lewis acids[J].J Polym Sci Pol Chem,2006,44(18):5247-53.
[6]Sunder A,Mulhaupt R,Frey H.Hyperbranched polyether-polyols based on polyglycerol:Polarity design by block copolymerization with propylene oxide[J].Macromolecules,2000,33(2):309-14.
[7]Kulinski Z,Piorkowska E,Gadzinowska K,et al.Plasticization of poly(L-lactide)with poly(propylene glycol)[J].Biomacromolecules,2006,7(7):2128-35.
[8]Piorkowska E,Kulinski Z,Galeski A,et al.Plasticization of semicrystalline poly(L-lactide) with poly(propylene glycol)[J].Polymer,2006,47(20):7178-88.
[9]Chisholm MH,Navarro-Llobet D,Simonsick WJ.A comparative study in the ring-opening polymerization of lactides and propylene oxide[J].Macromolecules,2001,34(26):8851-7.
[10]Aubrecht KB,Grubbs RB.Synthesis and characterization of thermo responsive amphiphilic block copolymers incorporating a poly(ethylene oxide-stat-propylene oxide) block[J].J Polym Sci Pol Chem,2005,43(21):5156-67.
[11]涂建军,王荣伟,张惠明,金晖.低不饱和度聚醚多元醇的制备方法[P].CN 1566184A,2005.
[12]Hyon SH,Jamshidi K,Ikada Y.Synthesis of polylactides with different molecular weights[J].Biomaterials,1997,18(22):1503-8.
[13]Li XB,Cao HB,Zhang Y.Thermal degradation kinetics of rigid polyurethane foams blown with water[J].Journal of Applied Polymer Science,2006,102(5):4149-56.
[14]Tuominen J,Kylma J,Kapanen A,et al.Biodegradation of lactic acid based polymers under controlled composting conditions and evaluation of the ecotoxicological impact[J].Biomacromolecules,2002,3(3):445-55.
[15]Stolt M,Hiltunen K,Sodergard A.Use of iron monocarboxylates in the two-step preparation of poly(ester-urethane)s[J].Biomacromolecules,2001,2(4):1243-8.
[16]Schwach G,Coudane J,Engel R,et al.More about the polymerization of lactides in the presence of stannous octoate[J].J Polym Sci Pol Chem,1997,35(16):3431-40.
[17]Schwach G,Coudane J,Engel R,et al.Zn lactate as initiator of DL-lactide ring opening polymerization and comparison with Sn octoate[J].Polym Bull,1996,37(6):771-6.
[18]Schwach G,Coudane J,Engel R,et al.Ring opening polymerization of D,L-lactide in the presence of zinc metal and zinc lactate[J].Polym Int,1998,46(3):177-82.
[19]Li SM,Rashkov I,Espartero JL,et al.Synthesis,characterization,and hydrolytic degradation of PLA/PEO/PLA triblock copolymers with long poly(L-lactic acid)blocks[J].Macromolecules,1996,29(1):57-62.
[20]Kim SH,Han YK,Ahn KD,et al.Preparation of Star-Shaped Polylactide with Pentaerythritol and Stannous Octoate[J].Makromolekulare Chemie-Macromolecular Chemistry and Physics,1993,194(12):3229-36.
[21]Arvanitoyannis I,Nakayama A,Kawasaki N,et al.Novel Star-Shaped Polylactide with Glycerol Using Stannous Octoate or Tetraphenyl Tin as Catalyst .1. Synthesis,Characterization and Study of Their Biodegradability [J]. Polymer, 1995, 36(15):2947-56.
[22]Yang L, Heatley F, Blease TG, et al. A study of the mechanism of the oxidative thermal degradation of poly(ethylene oxide) and poly(propylene oxide) using H-1-and C-13-NMR [J]. Eur Polym J, 1996, 32(5): 535-47.
[23]Flory PJ. Principles of polymer chemistry [M]. New York: Cornell Univ. Press,Ithaca, 1953.
[24] Hoffman JD, Miller RL. Kinetics of crystallization from the melt and chain folding in polyethylene fractions revisited: Theory and experiment [J]. Polymer, 1997,38(13): 3151-212.
[25]Vasanthakumari R, Pennings AJ. Crystallization Kinetics of Poly(L-Lactic Acid) [J]. Polymer, 1983, 24(2): 175-8.
[26]Pyda M, Bopp RC, Wunderlich B. Heat capacity of poly(lactic acid) [J]. J Chem Thermodyn, 2004, 36(9): 731-42.
[27]Day M, Nawaby AV, Liao X. A DSC study of the crystallization behavior of polylactic acid and its nanocomposites [J]. J Therm Anal Calo, 2006, 86(3): 623-9.
[28]Desantis P, Kovacs AJ. Molecular Conformation of Poly(S-Lactic Acid) [J].Biopolymers, 1968, 6(3): 299-306.
[29]Kobayashi J, Asahi T, Ichiki M, et al. Structural and Optical-Properties of Poly Lactic Acids [J]. J Appl Phys, 1995, 77(7): 2957-73.
[30]Hoogsteen W, Postema AR, Pennings AJ, et al. Crystal-Structure, Conformation,and Morphology of Solution-Spun Poly(L-Lactide) Fibers [J]. Macromolecules, 1990,23(2): 634-42.
[31]Eling B, Gogolewski S, Pennings AJ. Biodegradable Materials of Poly(L-Lactic Acid) .1. Melt-Spun and Solution-Spun Fibers [J]. Polymer, 1982, 23(11): 1587-93.
[32]Puiggali J, Ikada Y, Tsuji H, et al. The frustrated structure of poly(L-lactide) [J].Polymer, 2000,41(25): 8921-30.
[33]Sawai D, Takahashi K, Imamura T, et al. Preparation of oriented beta-form poly(L-lactic acid) by solid-state extrusion [J]. J Polym Sci Pt B-Polym Phys, 2002,40(1): 95-104.
[34]Sawai D, Takahashi K, Sasashige A, et al. Preparation of oriented beta-form poly(L-lactic acid) by solid-state coextrusion: Effect of extrusion variables [J]. Macromolecules, 2003, 36(10): 3601-5.
[35]Garkhal K, Verma S, Jonnalagadda S, et al. Fast degradable poly(L-lactide-co-epsilon-caprolactone) microspheres for tissue engineering:Synthesis, characterization, and degradation behavior [J]. J Polym Sci Pol Chem,2007, 45(13): 2755-64.
[36]Pan P, Kai W, Zhu B, et al. Polymorphous crystallization and multiple melting behavior of Poly(L-lactide): Molecular weight dependence [J]. Macromolecules, 2007,40(19): 6898-905.
[37]Wu T, He Y, Fan ZY, et al. Investigations on the morphology and melt crystallization of poly(L-lactide)-poly(ethylene glycol) diblock copolymers [J].Polymer Engineering and Science, 2008, 48(3): 425-33.
[1]Jiang HL,Zhu KJ.Synthesis,characterization and in vitro degradation of a new family of alternate poly(ester-anhydrides) based on aliphatic and aromatic diacids[J].Biomaterials,2001,22(3):211-8.
[2]Slivniak R,Domb AJ.Stereocomplexes of enantiomeric lactic acid and sebacic acid ester-anhydride triblock copolymers[J].Biomacromolecules,2002;3(4):754-60.
[3]Huang JCS,Aditya S.;Wang,Ming Song.Biodegradable plastics:a review.[J].Advances in Polymer Technology,1990,10(1):23-30.
[4]Mochizuki M,Mukai K,Yamada K,et al.Structural effects upon enzymatic hydrolysis of poly(butylene succinate-co-ethylene succinate)s[J].Macromolecules,1997,30(24):7403-7.
[5] Liu LJ, Li SM, Garreau H, et al. Selective enzymatic degradations of poly(L-lactide) and poly(epsilon-caprolactone) blend films [J]. Biomacromolecules,2000, 1(3): 350-9.
[6] Li SM, Espartero JL, Foch P, et al. Structural characterization and hydrolytic degradation of a Zn metal initiated copolymer of L-lactide and epsilon-caprolactone [J]. J Biomater Sci-Polym Ed, 1996, 8(3): 165-87.
[7] Arvanitoyannis I, Nakayama A, Kawasaki N, et al. Novel Star-Shaped Polylactide with Glycerol Using Stannous Octoate or Tetraphenyl Tin as Catalyst .1. Synthesis,Characterization and Study of Their Biodegradability [J]. Polymer, 1995, 36(15):2947-56.
[8] Dorgan JR, Lehermeier HJ, Palade LI, et al. Polylactides: Properties and prospects of an environmentally benign plastic from renewable resources [J].Macromol Symp, 2001, 175:55-66.
[9] Jacobsen S, Degee PH, Fritz HG, et al. Polylactide (PLA) - A new way of production [J]. Polym Eng Sci, 1999, 39(7): 1311-9.
[10]Grijpma DW, Vanhofslot RDA, Super H, et al. Rubber Toughening of Poly(Lactide) by Blending and Block Copolymerization [J]. Polym Eng Sci, 1994,34(22): 1674-84.
[11] Stolt M, Hiltunen K, Sodergard A. Use of iron monocarboxylates in the two-step preparation of poly(ester-urethane)s [J]. Biomacromolecules, 2001, 2(4): 1243-8.
[12]Tuominen J, Kylma J, Kapanen A, et al. Biodegradation of lactic acid based polymers under controlled composting conditions and evaluation of the ecotoxicological impact [J]. Biomacromolecules, 2002, 3(3): 445-55.
[13]Nakayama Y, Yamaguchi R, Tsutsumi C, et al. Synthesis of poly(ester-urethane)s from hydroxytelechelic polylactide: Effect of initiators on their physical and degradation properties [J]. Polym Degrad Stabil, 2008, 93(1): 117-24.
[14] Harris LG, Mead L, Muller-Oberlander E, et al. Bacteria and cell cytocompatibility studies on coated medical grade titanium surfaces [J]. J Biomed Mater Res Part A, 2006, 78A(1): 50-8.
[15]Borda J, Bodnar I, Keki S, et al. Optimum conditions for the synthesis of linear polylactic acid-based urethanes [J]. J Polym Sci Pol Chem, 2000, 38(16): 2925-33.
[16]Min CC, Cui WJ, Bei JZ, et al. Biodegradable shape-memory polymer-polylactideco-poly(glycolide-co-caprolactone) multiblock copolymer [J].Polym Adv Technol, 2005, 16(8): 608-15.
[17]Alteheld A, Feng YK, Kelch S, et al. Biodegradable, amorphous copolyester-urethane networks having shape-memory properties [J]. Angew Chem-Int Edit, 2005, 44(8): 1188-92.
[18]Di YW, Iannace S, Di Maio E, et al. Reactively modified poly(lactic acid):Properties and foam processing [J]. Macromol Mater Eng, 2005, 290(11): 1083-90.
[19]Cohn D, Hotovely-Salomon A. Biodegradable multiblock PEO/PLA thermoplastic elastomers: molecular design and properties [J]. Polymer, 2005, 46(7):2068-75.
[20]Loh XJ, Tan YX, Li ZY, et al. Biodegradable thermogelling poly(ester urethane)s consisting of poly(lactic acid) - Thermodynamics of micellization and hydrolytic degradation [J]. Biomaterials, 2008, 29(14): 2164-72.
[21] Choi NY, Kelch S, Lendlein A. Synthesis, shape-memory functionality and hydrolytical degradation studies on polymer networks from poly(rac-lactide)b-poly(propylene oxide)-b-poly(rac-lactide) dimethacrylates [J]. Adv Eng Mater, 2006, 8(5): 439-45.
[22] Chattopadhyay DK, Sreedhar B, Raju K. The phase mixing studies on moisture cured polyurethane-ureas during cure [J]. Polymer, 2006, 47(11): 3814-25.
[23]Dounis DV, Wilkes GL. Structure-property relationships of flexible polyurethane foams [J]. Polymer, 1997, 38(11): 2819-28.
[24] Seymour RW, Cooper SL. Thermal-Analysis of Polyurethane Block Polymers [J].Macromolecules, 1973, 6(1): 48-53.
[25]Swamy BKK, Siddaramaiah, Somashekarappa H, et al. Structure-property relationship in polyaniline-filled castor oil based chain extended polyurethanes [J].Polym Eng Sci, 2004, 44(4): 772-8.
[26] Leung LM, Koberstein JT. Dsc Annealing Study of Microphase Separation and Multiple Endothermic Behavior in Polyether-Based Polyurethane Block Copolymers [J]. Macromolecules, 1986, 19(3): 706-13.
[27]Yilgor I, Yilgor E, Guler IG, et al. FTIR investigation of the influence of diisocyanate symmetry on the morphology development in model segmented polyurethanes [J]. Polymer, 2006, 47(11): 4105-14.
[28] Aneja A, Wilkes GL. Hard segment connectivity in low molecular weight model 'trisegment' polyurethanes based on monols [J]. Polymer, 2004, 45(3): 927-35.
[29]Elwell MJ, Ryan AJ, Grunbauer HJM, et al. An FT ir study of reaction kinetics and structure development in model flexible polyurethane foam systems [J]. Polymer, 1996,37(8):1353-61.
[30]Aneja A,Wilkes GL.On the issue of urea phase connectivity in formulations based on molded flexible polyurethane foams[J].J Appl Polym Sci,2002,85(14):2956-67.
[31]Elwell MJ,Ryan AJ,Grunbauer HJM,et al.Structure Development Via Ft-Ir Spectroscopy,Synchrotron Saxs and Rheology During the Reactive Processing of Flexible Polyurethane Foam[J].Plastics Rubber and Composites Processing and Applications,1995,23(4):265-76.
[32]Crawford DM,Bass RG,Haas TW.Strain effects on thermal transitions and mechanical properties of thermoplastic polyurethane elastomers[J].Thermochimica Acta,1998,323(1-2):53-63.
[33]Coleman MM,Skrovanek DJ,Hu JB,et al.Hydrogen-Bonding in Polymer Blends.1.Ftir Studies of Urethane Ether Blends[J].Macromolecules,1988,21(1):59-65.
[34]Romanova V,Begishev V,Karmanov V,et al.Fourier transform Raman and Fourier transform infrared spectra of cross-linked polyurethaneurea films synthesized from solutions[J].Journal of Raman Spectroscopy,2002,33(10):769-77.
[35]麦杭珍.可生物降解材料-聚乳酸的研究[D];深圳,华南理工大学,2001.
[36]Ren ZY,Ma DZ,Yang XZ.H-bond and conformations of donors and acceptors in model polyether based polyurethanes[J].Polymer,2003,44(20):6419-25.
[37]张俐娜,薛奇,莫志深,金熹高.高分子物理近代研究方法[M].第二版.武汉:武汉大学出版社,2006.
[38]Krol P,Pilch-Pitera B.Phase structure and thermal stability of crosslinked polyurethane elastomers based on well-defined prepolymers[J].J Appl Polym Sci,2007,104(3):1464-74.
[39]Aneja A,Wilkes GL.Exploring macro- and microlevel connectivity of the urea phase in slabstock flexible polyurethane foam formulations using lithium chloride as a probe[J].Polymer,2002,43(20):5551-61.
[40]Kaushiva BD,McCartney SR,Rossmy GR,et al.Surfactant level influences on structure and properties of flexible slabstock polyurethane foams[J].Polymer,2000,41(1):285-310.
[1]Arvanitoyannis I,Nakayama A,Kawasaki N,et al.Novel Star-Shaped Polylactide with Glycerol Using Stannous Octoate or Tetraphenyl Tin as Catalyst.1.Synthesis,Characterization and Study of Their Biodegradability[J].Polymer,1995,36(15):2947-56.
[2]Liu L J,Li SM,Garreau H,et al.Selective enzymatic degradations of poly(L-lactide) and poly(epsilon-caprolactone) blend films[J].Biomacromolecules,2000,1(3):350-9.
[3]Li SM,Espartero JL,Foch P,et al.Structural characterization and hydrolytic degradation of a Zn metal initiated copolymer of L-lactide and epsilon-caprolactone [J].J Biomater Sci-Polym Ed,1996,8(3):165-87.
[4]Vert M,Schwach G,Engel R,et al.Something new in the field of PLA/GA bioresorbable polymers?[J].Journal of Controlled Release,1998,53(1-3):85-92.
[5]Garlotta D.A literature review of poly(lactic acid)[J].Journal of Polymers and the Environment,2001,9(2):63-84.
[6]Krouse SA,Schrock RR,Cohen RE.Ring-Opening Polymerization of Cyclooctyne[J].Macromolecules,1987,20(4):903-4.
[7]Xu Y,He Y,Wei J,et al.Morphology and melt crystallization of PCL-PEG diblock copolymers[J].Macromolecular Chemistry and Physics,2008,209(17):1836 -44.
[8]徐颖.聚己内酯.聚乙二醇二嵌段共聚物的结晶与形态结构[D].上海;复旦大学,2009.
[9]齐春艳.含新型膦亚胺配体的锂、镁、铝、锡(Ⅱ)和锌化合物的合成、表征及其催化环酯开环聚合研究[D].合肥;中国科学技术大学,2006.
[10]Tsuji H,Mizuno A,Ikada Y.Blends of aliphatic polyesters.Ⅲ.Biodegradation of solution-cast blends from poly(L-lactide) and poly(epsilon-caprolactone)[J].J Appl Polym Sci,1998,70(11):2259-68.
[11]Lefebvre F,David C,Vanderwauven C.Biodegradation of Polycaprolactone by Microorganisms from an Industrial Compost of Household Refuse[J].Polym Degrad Stabil,1994,45(3):347-53.
[12]Akahori S,Osawa Z.Preparation and Biodegradation of Polycaprolactone-Paper Composites[J].Polym Degrad Stabil,1994,45(3):261-5.
[13]Eldsater C,Erlandsson B,Renstad R,et al.The biodegradation of amorphous and crystalline regions in film-blown poly(epsilon-caprolactone)[J].Polymer,2000,41(4):1297-304.
[14]Pitt CG,Gratzl MM,Kimmel GL,et al.Aliphatic Polyesters.2.the Degradation of Poly(DI-Lactide),Poly(Epsilon-Caprolactone),and Their Copolymers Invivo[J].Biomaterials,1981,2(4):215-20.
[15]Sawhney AS,Hubbell JA.Rapidly Degraded Terpolymers of Dl-Lactide,Glycolide,and Epsilon-Caprolactone with Increased Hydrophilicity by Copolymerization with Polyethers[J].Journal of Biomedical Materials Research,1990,24(10):1397-411.
[16]Fukuzaki H,Yoshida M,Asano M,et al.Synthesis of Low-Molecular-Weight Copoly(L-Lactic Acid Epsilon-Caprolactone) by Direct Copolycondensation in the Absence of Catalysts,and Enzymatic Degradation of the Polymers[J].Polymer,1990,31(10):2006-14.
[17]Perego G,Vercellio T,Balbontin G.Copolymers of L-Lactide and D,L-Lactide with 6-Caprolactone- Synthesis and Characterization[J].Makromolekulare Chemie-Macromolecular Chemistry and Physics,1993,194(9):2463-9.
[18]Zhang XC,Wyss UP,Pichora D,et al.Biodegradable Polymers for Orthopedic Applications- Synthesis and Processability of Poly(L-Lactide) and Poly(Lactide-Co-Epsilon-Caprolactone)[J].Journal of Macromolecular Science-Pure and Applied Chemistry,1993,A30(12):933-47.
[19]Grijpma DW,Pennings AJ.Polymerization Temperature Effects on the Properties of L-Lactide and Epsilon-Caprolactone Copolymers[J].Polym Bull,1991,25(3):335-41.
[20]Kricheldorf HR,Kreiser I.Polylactones.13.Trans-Esterification of Poly(L-Lactide) with Poly(Glycolide),Poly(Beta-Propiolactone),and Poly(Epsilon-Caprolactone)[J].Journal of Macromolecular Science-Chemistry,1987,A24(11):1345-56.
[21]Kasperczyk J,Bero M.Coordination Polymerization of Lactides.4.the Role of Transesterification in the Copolymerization of L,L-Lactide and Epsilon-Caprolactone [J]. Makromolekulare Chemie-Macromolecular Chemistry and Physics, 1993, 194(3):913-25.
[22]Grijpma DW, Pennings AJ. (Co)Polymers of L-Lactide .1. Synthesis,Thermal-Properties and Hydrolytic Degradation [J]. Macromolecular Chemistry and Physics, 1994, 195(5): 1633-47.
[23]Rashkov I, Manolova N, Li SM, et al. Synthesis, characterization, and hydrolytic degradation of PLA/PEO/PLA triblock copolymers with short poly(L-lactic acid) chains [J]. Macromolecules, 1996, 29(1): 50-6.
[24]Grijpma DW, Vanhofslot RDA, Super H, et al. Rubber Toughening of Poly(Lactide) by Blending and Block Copolymerization [J]. Polym Eng Sci, 1994,34(22): 1674-84.
[25]Chattopadhyay DK, Sreedhar B, Raju K. The phase mixing studies on moisture cured polyurethane-ureas during cure [J]. Polymer, 2006, 47(11): 3814-25.
[26]Coleman MM, Skrovanek DJ, Hu JB, et al. Hydrogen-Bonding in Polymer Blends .1. Ftir Studies of Urethane Ether Blends [J]. Macromolecules, 1988, 21(1):59-65.
[27]Romanova V, Begishev V, Karmanov V, et al. Fourier transform Raman and Fourier transform infrared spectra of cross-linked polyurethaneurea films synthesized from solutions [J]. Journal of Raman Spectroscopy, 2002, 33(10): 769-77.
[28]Elwell MJ, Ryan AJ, Grunbauer HJM, et al. An FT ir study of reaction kinetics and structure development in model flexible polyurethane foam systems [J]. Polymer,1996,37(8): 1353-61.
[29]Dounis DV, Wilkes GL. Structure-property relationships of flexible polyurethane foams [J]. Polymer, 1997, 38(11): 2819-28.
[30]Yilgor I, Yilgor E, Guler IG, et al. FTIR investigation of the influence of diisocyanate symmetry on the morphology development in model segmented polyurethanes [J]. Polymer, 2006, 47(11): 4105-14.
[31]Elwell MJ, Ryan AJ, Grunbauer HJM, et al. Structure Development Via Ft-Ir Spectroscopy, Synchrotron Saxs and Rheology During the Reactive Processing of Flexible Polyurethane Foam [J]. Plastics Rubber and Composites Processing and Applications, 1995, 23(4): 265-76.
[32] Crawford DM, Bass RG, Haas TW. Strain effects on thermal transitions and mechanical properties of thermoplastic polyurethane elastomers [J]. Thermochimica Acta, 1998, 323(1-2): 53-63.
[33]张俐娜,薛奇,莫志深,金熹高.高分子物理近代研究方法[M].第二版.武汉:武汉大学出版社,2006.
[34]Li XB,Cao HB,Zhang Y.Thermal degradation kinetics of rigid polyurethane foams blown with water[J].J Appl Polym Sci,2006,102(5):4149-56.
[35]Friedman HL.Kinetics of Thermal Degradation of Char-Forming Plastics from Thermogravimetry.Application to Phenolic Plastic[J].Journal of Polymer Science Part C-Polymer Symposium,1964,(6PC):183-95.