丝素蛋白共聚改性聚L-乳酸的研究
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摘要
聚乳酸(PLA)具有优异的力学性能、生物相容性和生物降解性能,在医学材料、纺织材料、塑料和涂料等领域具有广阔的应用前景。然而,PLA也存在一些缺陷,如亲水性差、缺乏细胞识别信号、细胞亲和性差等,这些缺陷限制了聚乳酸在组织工程材料和药物缓释体系中的应用。蚕丝素蛋白原料丰富,对人体细胞具有亲和性,用其改性聚乳酸材料,可以提高材料的生物相容性。
     本论文以辛酸亚锡作为催化剂,聚L-乳酸(PLLA)和丝素蛋白(SF)为原料,固相聚合制备共聚物(PSFLA)。采用粘度法、旋光法、红外光谱、差示扫描量法、X-射线衍射、核磁共振、凝胶色谱(GPC)、偏光显微镜、扫描电镜等方法对所得聚合物的相对分子质量、分子量分布、光学活性、热性能、微结构等进行了详细的研究;探讨了原料混合方法、原料配比等反应条件对PSFLA的结构与性能的影响。结果表明:以PLLA与SF为原料,Sn(Oct)2为催化剂,可以固相聚合制备共聚物PSFLA;固相聚合时,单体配比、混合方法等均对聚合物的光学活性和相对分子质量有影响,需要选择合适的投料比和混合方法;最佳反应条件为:固相聚合反应时间6 h,反应温度150℃,催化剂用量0.5 % (wt), PLLA/SF为6:1时可以制备光学活性较好,分子量较高的PSFLA。
     本论文以辛酸亚锡/萘二磺酸作为催化剂体系,L-丙交酯和SF为原料,开环聚合制备共聚物(PSFLA),采用粘度法、旋光法、红外光谱、差示扫描量法、偏光显微镜等方法对所得聚合物进行表征,探讨了原料配比、反应时间、反应温度、催化剂的用量等反应条件对PSFLA的结构与性能的影响。结果表明:以Sn(Oct)2/萘二磺酸为催化剂,以L-丙交酯与SF为原料,Sn(Oct)2/萘二磺酸为催化剂体系,可以开环聚合制备L-丙交酯/SF共聚物(PSFLA);开环聚合时,单体投料比、反应时间、反应温度、催化剂用量、催化剂配比等均对聚合物的光学活性和相对分子质量有影响,因此,需要优化聚合工艺;最佳反应条件为:开环聚合反应时间6 h,反应温度180℃,催化剂用量0.5 %(wt),催化剂配比1:1,L-丙交酯/SF为4:1。
     总之,本论文以聚L-乳酸和丝素蛋白为原料,锡盐为催化剂,采用固相聚合成功合成了丝素/聚L-乳酸共聚物;以丙交酯和丝素蛋白为原料,锡盐/质子酸体系为催化剂,采用开环聚合成功合成了丝素/ L-丙交酯共聚物,为聚乳酸的改性提供了新的方法,减少了环境污染,降低了产品成本。
Poly (lactic acid) (PLA) is one of the most important environmental friendly polymers because of their biodegradability,renewable resources, and excellent properties. PLA polymers can be employed as a promising cost-effective alternative to commodity petrochemical-based plastics so as to lessen the dependence of plastics on oil and diminish the pollution caused by waste plastic products.Silk fibroin (SF) can improve the bioco MPatibility of PLLA. But poly(lactic acid) also exists many defects, such as the bad hydrophily, short of the cell identification signal and the bad cell affinity and so on. These defects restrict the PLA’s application on the cell’s matrixes of organization engineering and the medical postpones explaining system.The silk fibroin (SF) with the endophilicity to the human body cell can be used to modify PLA materials to enhance the biological compatibility of PLAs.
     In this paper, PLLA and SF were polymerized through melt copolycondesation with Sn(Oct)2 as the catalyst, it was employed for the characterization of polymers with Viscometry, polarimetry, FT-IR,DSC,GPC,X-ray,and NMR,detected the effects of hybrid method,micro structure,molecular weight,and discussed the affect of PLA’s structure and performance for blend method and the proportion of material .The result indicates that:Optical purity and molecular weight of copolymer were changed with reaction conditions with Sn(Oct)2 as catalyst to solid polymerization;the best reaction conditon is 6 hours reaction time,150℃temperature,PLLA/SF for 6/1,and 0.5 % (wt)catalysts.
     In this paper, LLA and SF were polymerized through ring-opening copolymerization with Sn(Oct)2/naphthalene disulfonic acid as the catalyst system.it was employed for the characterization of polymers with Viscometry, polarimetry, FT-IR and DSC,and detected the effects of hybrid method, reaction time, temperature, catalyst weight.The result indicates that: Sn(Oct)2/naphthalene disulfonic acid as catalyst systems is suitably to ring-opening polymerization; the best reaction conditon is 6 hours reaction time,180℃reaction temperature, 4/1 for LLA/SF , 0.5 % (wt)catalysts,and 1:1 for the proportion of catalysts.
     All in all, PLLA and SF were polymerized through solid polymerization with Tin salt as catalyst to prepare copolymers; and LLA and SF were polymerized through ring-opening polymerization Tin salt / proton acid as catalyst systems to prepare copolymers,which will deduce PLA cost and lessen the pollution of solvents during its process.
引文
1 Hassan S, Karin S. Mechanical properties and porosity of polylactide for biomedical applications[J]. J. Appl. Polym.Sci.2008,107(1):82~93
    2 Jie Ren, Hongye Fu, Tianbin Ren,etl. Preparation, characterization and properties of binary and ternary blends with thermoplastic starch, poly(lactic acid) and poly(butylene adipate-co-terephthalate) Carbohydrate[J]. Polym.sci. 2009,77(3):576~582
    3 Klieheldorf H R. Polylaetones Sn(Ⅱ) Oetoate-initiated Polymerization of L-Laetide[J].Polym.1995,36: 1253~1259
    4王军,张健.聚乳酸的合成及其在生物医药领域的应用进展[J].化学与生物工程2008,25(7):22~27
    5 Carothers W H, Dorough G L, Van Na F J,etl. Studies of polymerization and ring formation the reversible polymerization of six-membered cyclic esters [J]. J.Am.Chem.Soc. 1932, 54: 761~772
    6 Masaka K I ,Nagai T. Synthesis and in vitro degradation of low- molecular -weight copolyesters composed of L-lactic acid and aromatic hydroxy acids [J]. Makromol.Chem.1990,k191:2077~2082
    7 Ajioka M, nomoto K E, Suzuki, etl. Basic properities of polylactic acid produced by the direct condensation polymerization of lactic acid[J],Bull. Chem. Soc. Jpn. 1995, 68:2125~2131
    8 Ajioka M, Suizu K,Higuchi,etl. Aliphatic polyesters and their copolymers synthesized through direct condensation polymerization [J], Polym. Degrad. Stab. 1998, 42: 137~143
    10赵耀明,张军,麦杭珍等.直接缩聚法合成聚乳酸的研究[J].合成纤维,2001,30(3):3~5
    11秦志忠,秦传香,曹雪琴等.聚乳酸的直接合成研究(Ⅱ) [J].合成技术及用,2003,18(3):1~2
    12王征,王婷,赵学明等.直接缩合法合成聚乳酸[J].天津大学学报,2000,33(1):48~50
    13 Achmada F, Yamanea K, Quana S,etl. Synthesis of polylactic acid by direct polycondensation under vacuum without catalysts, solvents and initiators, Chemical Engineering Journal[J], 2009,151 (15):342~350
    14 Maharana T, Mohanty B. Negi Melt–solid polycondensation of lactic acid and its Biodegradibility Progress[J]. Polym. Sci. 2009,34(1):99~124
    15 Takasu A, Kawa Y, Abayashi T,etl. Direct dehydration polycondensation of lactic acid catalyzed by water-stable lewis acids[J]. J.Polym.Sci.Part A:Polym.Chem.2006,44(18):524~253
    16任杰,王秦峰,张乃文等.熔融缩聚法制备聚乳酸[J].塑料工业. 2004,32(5):1~4
    17 Lee C W, Miyamoto M. Meltpolycondensation of L-actic acid with Sn (II) catalysts activated by various protonacids: A direct manufacturing route to high molecular weight poly (L-la-cticacid) [J]. Polym.Sci, PartA:Polym Chem,2000, 3(9):1673~1679
    18 Lee C W. Melt/solid Polycondensation of L-lacticacid:An alternative route to poly(L-lacticacid) with high molecular weight[J]. 2001,42:5059~5062
    19 Moon S I, Lee C W, Taniguchi I,etl. Melt/solid polymerization of L-lactic acid: an alternative routes to poly(L-lactic acid)with high molecular weight[J]. Polym.2001,42(11):5059~5062
    20沈之荃,孙俊全,吴良江等.稀土配位催化合成聚乳酸[J].化学学报.1990,48:685
    21汪朝阳,赵耀明,麦杭珍等.熔融-固相聚合法中固相聚合对聚乳酸合成的影响[J].材料科学与工程,2002,20(3):403~406
    22宇恒星,王朝生,黄南薰等.聚乳酸的聚合方法[J].化工新型材料,2002,30(3):16~18
    23 Moon S I, Lee C W, Miyamoto M,etl. Melt polycondensation of L-lactic acid with Sn (Ⅱ) catalysts activated by various proton acids: A direct manufacturing route to high molecular weight poly (L-lactic acid) [J]. J Polym Sci. 2000, 38(9):1673~1679
    24 Moon S I, Lee C W. Melt/solid polymerization of L-lactic acid: an alternative routes to poly (L-lactic acid) with high molecularweight[J]. Polymer,2001,42(11):5059~5062
    25汪朝阳,赵海军,侯晓娜等.聚乳酸合成研究进展[J].高分子材料科学与程,2009,25(3):39~46
    26 Gao Q W. Direct Synthesis with Melt Polymerization and Microstructure Analysis of Homo- and Copolymer of L-lactic Acid[D]. DongHua University. 2002.5
    27曹新鑫,戴星红,刘静静等.生物高分子聚乳酸的合成综述[J].安徽化工,2008,34(9):1
    28 Kricheldorf H R. Polylactones Anionic polymerization of L-lactide in solution [J]. Makromol. Chem. 1990, 191:1057~1066
    29 Jonte J M, Dunsing R ,Kricheldorf H R,etl. Polylactones Cationic polymerization of lactones by means of alkyl sulfonates [J]. Macromol Sci.Chem. 1986, A23:495~514
    30 Kricheldorf H R ,Dunsing R. Polylactones Machanism of the cationic polymerization of L, L-dilactide[J]. Makro.Chem.1986,187:1611~1625
    31 Krieiser H R. Polylactones Transesterification of poly(L-lactic acid) with poly(glycolide), poly(β-propiolactone), and poly(ε-caprolactone) [J]. Macromol Sci. Chem.1987,A24 (1):1345~1354
    32 Cherdron H, Ohse H, Korte F,etl. Die polymerization von lactonen, Teil I Homopoly- merisation 4-, 6- and 7-gliedriger lactone mit Kationschen Initiatoren[J]. Makromol.Chem.1962,56:179~186
    33 Kricheldorf H R,Sumbel M. Polylactones-18- Polymerization of L, L-lactide with Sn (Ⅱ) and Sn (Ⅳ) halogenides[J]. Eur.Polym. 1989,25:585~591
    34 Dubois Ph, Jacobs C, Jerome R,etl. Macromolecular engineering of poly-lactones and polylactides. Mechanism and kinetics of lactide homo- polymerization by aluminium is opropoxide[J]. Macromolecules.1991,24:2266~2270
    35 Jacobes C, Dubois Ph, Jerome R,etl. Macromolecular engineering of poly- lactones and polylactides.5.synthesis and characterization of diblock copolymers based on poly-ε-caprolactone and poly (L,L or D,L lactide) by aluminiumalkoxides[J].Macromoleculars, 1991,24:3027~3034
    36 L?fgren A, Albertsson A C, Ddubois P,etl. Recent advances in ring-opening polymerization of lactones and related compounds [J], Macromol.Sci.-Rev. Macromol. Chem. Phys. 1995, C35(3): 379~418
    37娄玲,尹静波,高战团等. L-丙交酯和聚L-乳酸的制备与性能[J].高分子材料科学与工程, 2003,19(2): 72~75
    38张科,王鹏,李文科等.聚乳酸的微波辐射合成方法研究[J].高分子材料科学与工程,2004,20(3):46~48
    39周贤爵,李进,邵惠丽等.超临界CO2中聚乳酸的合成及表征[J].高分子材料科学与工程,2005,21(3):66~69
    40卢泽俭,廖凯荣,李洪权等.高强度聚(L-乳酸)骨折内固定器件研制高相对分子质量聚(L-乳酸)的合成[J].中山大学学报(自然科学版),1999,38(5):36~39
    41方林霞,井强山,陈强等. L-丙交酯催化合成聚L-乳酸[J].信阳师范学院学报.2008,21(2):3~9
    42吴林波,王伟超,黄源等.一种制备羟基酸缩聚物的缩合聚合方法[P].2006,7
    43舒静,王鹏,张科等.聚D,L-丙交酯的常压微波辐射合成[J].高校化学工程学报, 2005,19 (4):488~502
    44曾庆慧,罗丙红,杨媛等.低温常压下高分子量左旋聚乳酸的微波合成及表征[J].功能材料,2007,38 (6):972~975
    45杨秀英,张德庆.微波法合成低分子量聚L-乳酸的研究[J].齐齐哈尔大学学报,2005,21(4):17~20
    46 yoda S,bratton D,mhowdl S,etl. Direct synthesis of poly(L-lactic acid) in supercritical carbon dioxide with dicyclohexyl-dimethylcarbodiimide and 4-dimethylamino pyridine[J]. Polym.2004,45(23):783~843
    47任杰,王秦峰,张乃文等.聚乳酸类聚酯及其共聚物制备的新方法[P]. 2007.2
    48李申,周晔,任天斌等.聚乳酸/淀粉复合材料的制备及性能研究[J].塑料,2006,35(4): 7~11.
    49顾书英,詹辉,任杰等.聚乳酸/PBAT共混物的制备及其性能研究[J].中国塑料,2006,20(10):39~42.
    50 Huiming X,Josepg X,Zheng A,etl. new approach in the study oftethered diblock copolymer surface morphology and its tethering density dependence[J]. Polym.2007,48:3732~3738
    51 Shinoda H, Asou Y, Kashima Y,etl. Amphiphilic biodegradable copolymer, poly(aspartic acid-co-lactide):acceleration of degradation rate and impro-vemnt of therrmal stability for (lactic acid), poly(butylenes succinate) and poly(ε-caprolactone) [J]. Polym.Degrad.Stab.2003,80(2):241~250
    52 Dubois P, Narayan R. Biodegradable compositions by reactive processing of aliphatic polyester/ polysac haride blends [J]. Macrom.Sym. 2003,198(1):233~244
    53 Jacobean S, Fritz H G. Plastizing polylactide is the effect of different Plastieizeo on the mechanical properties[J]. Polym.Sci.1999,39(7):1303~1310
    54 Chinsan W. Renewable resource-based composites of recycled natural fibers and maleated polylactide bioplastic: Characterization and biodegradability Polymer Degradation and Stability [J]. 2009, 94(7): 1076~1084
    55 Harshe Y M, Storti G, Morbidelli M,etl. Modeling polycondensation of lactic acid[J]. Macromol.Sympos. 2007,259:116~123
    56 Duigou A, Davies P, Baley C,etl. Seawater ageing of flax/poly(lactic acid) biocomposites Polymer Degradation and Stability[J]. 2009,94(7):1151~1162
    57 Jianbing Z, Yidong L, Qunying Z,etl. A novel biodegradable multiblock poly (ester urethane) containing poly(L-lactic acid) and poly(butylene succinate) blocks Polymer[J]. 2009,50(5):1178~1186
    58冉祥海.一种三元复配聚乳酸型复合材料及其应用[P]. 2006
    59冉祥海.三元复配可完全生物降解的聚乳酸型复合材料制备方法[P]. 2006
    60张磊,黄汉雄.聚乳酸/氯化钠共混物的流变性能[J].塑料科技2009,37(9):56~60
    61张清松,邓晶晶,贺湘伟等.增塑剂对聚乳酸/热塑性淀粉共混物结构与性能的影响[J].塑料工业. 2009,37(11):195~203
    62宋霞,冯钠,陈荣丰等.聚乳酸/EVA共混材料力学性能研究[J].化工新型材料.2009,37(9):12~19
    63舒晓军,杨青芳,杜江华等.聚乳酸的改性及应用[J].合成纤维工业.2006,29(6): 44~47
    64程蓉,钱欣.聚乳酸的改性及应用进展[J].化工进展, 2002, 21(11): 824~826
    65杨惠,刘文明,黄小强,李凤仪.聚乳酸合成及改性研究进展[J].南昌大学.2008,3:42~46
    66 Weifeng D, Jiayun Z, Aoyu S,etl. Synthesis, characterization and degradability of the comb-type poly(4-hydroxyl -ε- caprolactone-co-ε-caprolactone)-g-poly(l-lactide)[J]. Eur.Polym.2009, 45(6):1659~1667
    67 James P, Steven M, Sara R, etl. Functionalized poly(lactic-co-glycolic acid) enhances drug delivery and provides chemical moieties for surface engineering while preserving biocompatibility Acta Biomaterialia.2009,4(2):10~13
    68 Soni R K, Soam S, Dutt K,etl. Studies on biodegradability of copolymers of lactic acid, terephthalic acid and ethylene glycol[J]. Polym. 2009,94(3):432~437
    69宋谋道,余艺华.乳酸-羟基乙酸均聚物及共聚物得合成与结构表征[J].离子交换与吸附,1995, 11(3): 245~252
    70罗彦凤,曹雪波. PLA单体—丙交酯合成方法的研究进展[J].高分子材料科学与工程.2003,19(1):29~31
    71曹雪波,王远亮.马来酸酐改性聚乳酸的力学性能研究[J].高分子材料科学与工程,2002,18(1):115~118
    72唐智荣,黄虹.吗啉二酮衍生物与丙交酯的共聚[J].华东理工大学学报,2002, 28(6):618~620
    73 Zhu K J.“Super Microcapsules”(SMC), preparation and characterization of star polyethylene oxide(PEO)-polylactide(PLA) copolymers[J]. Polym. Sci:PartA:Polym.Chem.2004, 27(7):2151~2159
    74吴之中.聚乳酸一聚乙二醇嵌段共聚物及其交联聚氨酷弹性体的性能研究[J].信阳师范学院学报,1999,12(2):166~169
    75赵耀明,黄俊康,陈军武等.生物降解医用材料-聚乙丙交醋的研究[J].合成纤维工业,1997,20(4):1~4
    76蔡晴,贝建中,王身国等.乙交酯/丙交酯共聚物的体内外降解行为及生物相容性研究[J].功能高分子材料学报. 2001,13(3):249~254
    77苏思玲,金乐群,顾永安等. E-MA-GMA三嵌段共聚物对聚乳酸的增韧改性[J].高分子材料科学与工程,2008,24(4):1956~1959
    78尹静波,鲁晓春,曹燕琳等.柠檬酸酯增塑改性聚乳酸[J].高分子材料科学与工程2008,24(l):234~238
    79施云峰,谢德明,周长忍等.壳聚糖与丙交酯接枝共聚物的制备与表征[J].材料科学与工程学报2008,26(l):281~283
    80吴桐.聚乳酸-聚乙二醇共聚物结晶行为研究[J].高等学校化学学报,2006, 27 (11):53~57
    81 Jin K K, Park D J, Lee M S,etl. Immiscible polymer blends of semicrystalline bioco MPatible components [J]. Polym.2001,42(17):74~79
    82张敏.乳酸/己内酯对聚丁二酸丁二酯共聚改性的合成研究[J].现代化工,2007, 27(2):65~68
    83饶炬,龚飞荣,陈建定等.环状碳酸酯共聚改性聚乳酸性能[J].华东理工大学学报.2009,35(2):12~15
    84邵俊,赵耀明.原位法合成聚乳酸接枝淀粉共聚物的研究与应用[J].中国塑料. 2009,23(10):67~71
    85 Abe H,Tetsuka H,Doi Y,etl. Synthesis and characterization of pe-riodic co-polymers from L-lactic acid and L-alanine[J]. Polym.Japan. 2005,54(2):5243~5244
    86侯晓娜,汪朝阳,赵海军等.药物缓释材料聚(乳酸-丙氨酸)的直接法合成与表征[J].化工新型材料,2007,35(11):32~34
    87 Duan J F, Du J, Zheng Y B,etl. Synthesis and characterization of a novel biodegradable polymer polylactic acid-glycolic acid-4-hydroxyproline[J]. J Appl.Polym.Sci.2007,103(6):3585~3590
    88董锐,郑雪琴,唐兰勤等.聚乳酸-氨基酸共聚物的合成及表征[J].当代化工.2009,12,38(6):15~18
    89李明忠,严景.再生丝素的结构及其生物医学应用[J]. 2000,5:37~40
    90王佳培,胡建恩,白雪芳等.蚕丝素蛋白及其应用[J].精细与专用化学品,2004,12(12):13~14
    91 Shao Z.Nature F. 2002, 418: 741~743
    92宁丽,薛淼,黄海宁等.皮肤再生膜的生物相容性系列研究[J].中国修复重建外科杂志2000,14(1):44~48
    93吴徽宇.丝素蛋白作为生物医用材料的研究[J].材料导报,2001,15(2):50~51
    94 Freddi G, Romano M, Massafra M R,etl. Silk Fibroin/Cellulose Blend Films: Preparation, Structure, and Physical Properties [J]. Appl.Polym.Sci.1995, 56(12):1537~1545
    95李明忠,缪俊娜,柴玲华等.丝素/聚氨酯共混膜的性能[J].丝绸.2002(7):9~11
    96冯新星,郑桂芬,陈建勇等.纳米TiO2改性丝素膜制备工艺优化及其性能研究.浙江理工大学.2009
    97刘剑洪,于同隐.丝素蛋白纤维的接枝聚合Ⅰ.用四价铈盐引发丝素蛋白纤维接枝烯类紫外稳定剂[J功能高分子学报. 1989,2(4):261~266
    98刘剑洪,于同隐.丝素蛋白纤维的接枝聚合(Ⅱ) :无引发剂存在时丝素蛋白纤维接枝烯类单体[J].复旦学报(自然科学版). 1994,33(4):371~377
    99 Tsukada M, Shiozaki H. Characterization of methacrylonitrile-grafted silk fibers [J]. Appl Polym Sci. 1990, 39(6):1289~1297
    100连小洁,王松,朱鹤孙等.川芎嗪衍生物改性丝素材料体外抗凝血性研究[J].郑州大学学报. 2009,30(1):104~109
    101张光先,鲁成,卢明等.腈纶织物接枝丝素蛋白的工艺条件及服用性能研究[J].蚕业科学. 2009, 35(3):10~13
    102周燕.丝素/聚乳酸生物降解膜的制备及性能研究[D]. 2006,苏州大学本科论文
    103缪秋菊,左保齐,秦志忠等.丝素/聚乳酸静电纺丝的研究[J],2007,5(14)
    104陈建勇,张加忠,冯新星等.聚乳酸/丝素共混膜的制备及其性能[J]化工学报2008,5(9):16~17
    105 Cook D A, Gao N N. Cell Adhesion on Artificial Materials for Tissue Engineering [J]. Biomed MaterRes,2004,35(4):513~523
    106 Barrera D A, Zylstra E,Lausbury P T,etl. Synthesis and RGD peptide modification of a new biodegradable copolymer: poly (lactic acid-co-lysine) [J]. Am Chem Soc, 2004, 115(23):11010~11011
    107 Jin S, Gonsalves K E. Synthesis of poly (l-lactide-co-serine) and its graft copolymers with poly(ethylene glycol)[J]. Polym. 1998,39(21):5155~5162
    108 George J, Morita M. Synthesis and Characterization of Photo-cross-linked Networks Based on Lactic Acid and Serine Copolymers[J]. Macromolecules, 1999, 32(6):1853~1858
    109寇琴.丝素蛋白开环共聚改性聚D,L-乳酸的研究.南京林业大学硕士生论文.2008
    110周壮丽.熔融/固相聚合制备聚乳酸与丝素蛋白共聚物.南京林业大学硕士生论文.2009
    111吴国成. L-乳酸齐聚物与蚕丝素蛋白共聚物的制备和研究.南京林业大学硕士生论文.2009
    112 Jin S, Gonsalves K D. Polym. 1998, 39(21):5155~5162
    113 Quirk R A, Chan W C,Davies M C,etl. Bio. 2001,22(8):865~872.
    114 George J, Morita M. Macromolecules.1999,32(6):1853~1858
    115 Barreraa D A, Zylstra E, Lausbury P T,etl. Macromolecules.2005,28(2):425~432
    116田怡,钱欣.聚乳酸的结构性能与展望[J].石化技术与应用, 2006,24(3):233~237
    117 Gotoh Y. Chemical Modification of Silk Fibroin with Cyanuric Chloride-Activated poly(ethylene glycol):analyses of reaction site by 1H-NMR spectroscopy and conformation of the conjugates[J], Bio Chem.1993,4:554~559
    118 Asakura T. NMR of Silk Fiborin.4 Temperature-and Urea-Induced Helix-Coil Transitions of the-(Ala)n-Sequence in Silk Fiborin Protein Monitored by 13C NMR Spectroscopy[J]. Macromolecules,1985,18: 2614~2619
    119 Magoshi J. Physical properties and structrure of Silk.Ⅴ[J]. Journal of polymer science:Polym.1977, 15:1675~1683
    120 Yumin Y. Development and evaluation of silk fibroin-based nerve grafts used for peripheral nerve regeneration [J]. Bio. 2007,28:5526~5535
    121 Ando A, Kimura K, Onda Y,etl. New Attempt at the Stereoselective polymerization of Lactide by Using Crystallization during Polymerization[J]. Mactomol,Rapid Commun, 2005, 26: 98~102
    122张倩,梁海林,张小华.生物降解材料聚丙交酯的合成[J].塑料工业,2002,30(2):10~12
    123何忠琴.丝素蛋白的高次结构[J].国外丝绸. 2008,2:1~4
    124高勤卫,李明子,董晓等.聚乳酸的立构选择性聚合的研究进展[J].现代化工.2007,27(10): 20~24
    125 Arimura H. The formation of biodegradable polymeric micelles from newly synthesized poly (aspartic acid) block polylactide AB-type diblock copolymers [J]. MactomolRapid Commun. 2004,25:743~740

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