摘要
当前，对现有高分子材料进行改性以获得综合性能优良的聚合物新材料是高分子材料科学研究的重要课题之一。聚苯硫醚(PPS)作为第六大特种工程塑料，具有优良的热稳定性、良好的电绝缘性、耐腐蚀性和自阻燃性，已经广泛应用于汽车、电子电器和航空航天等各个领域。但纯PPS由于结构上的特点而具有一个突出的缺点——脆性大、冲击强度低，限制了其应用范围的进一步扩大。目前，研究者主要采用与其他聚合物共混制备合金以及添加纳米粒子的方法来提高PPS韧性。然而这些改性方法在提高PPS韧性的同时往往以牺牲PPS的优异性能来换取目标性能的提高，比如传统的弹性体在显著增韧的同时会给材料的强度、模量和热性能带来损失。虽然纳米粒子可以同时增韧增强聚合物，但是它对聚合物冲击性能的提高幅度有限。因此如何在保证材料具有良好的强度和热性能的同时，显著改善PPS的抗冲击性，成为PPS增韧改性研究领域努力追求的目标。
本论文在传统的弹性体增韧聚合物的基础上，选择带有支链和不饱和键结构的柔性聚合物LDPE与纳米SiO_2刚性粒子增韧增强PPS，并采用直接熔融共混、溶液包覆共混、溶液接枝共混和熔体(熔融)接枝共混四种方法制备复合材料。运用FTIR、SEM、DSC、PLM、TGA等测试手段，详细的研究了复合体系的力学性能与微观结构及其相互关系以及SiO_2／LDPE分散相的增韧增强机制。主要研究内容及结果如下：
1．首次采用LDPE熔融接枝改性SiO_2协同增韧增强PPS，材料的冲击强度被提高至85.1KJ/m~2，是纯PPS的3.7倍；拉伸强度和弯曲强度分别提高27％和9％。SiO_2-LDPE包覆结构和包覆球中网络结构的形成、基体-包覆球界面的粘结粗
At present, it has been an important object to obtain new polymer materials with excellent properties by means of modification of existing polymer materials. As the sixth high performance plastics, poly(phenylene sulfide) (PPS) has been widely used in auto, electronics industry and military field, due to its good combination of properties such as high thermal stability and electrical insulating ability, corrosion resistance and excellent self flame-retardance. But neat PPS has a deadly shortcoming of low impact strength, which limits the further use of it. Blending PPS with other plastics and filling with nanoparticles are most performed to improve the impact strength of PPS. However, conventional blending methods always decrease other properties while gaining the deserved ones. For example, elastomer can weaken the strength, modulus and thermal performances while improve the toughness significantly. Though nanoparticles can enforce and toughen the polymer simultaneously, it increases the toughness limitedly. How to obtain higher tensile or yield strength and thermal behavior as the impact strength increases has been an object hunted for by many PPS studiers on toughening modification.
Based on the conventional elastomer toughening theory, thermoplastic low density polyethylene (LDPE) with branch chains and unsaturated double bonds was chosen as the toughening component. The LDPE together with rigid nano-SiO_2 particles is expected to have a synergistic toughening effect on PPS. The relationship between the mechanical performance and microstructure of composites was investigated by FTIR, SEM, DSC, PLM, et al. The toughening mechanism by SiO_2/LDPE composition dispersed phase was also explored and discussed. The main work and results obtained were listed as follows.
1. For the first time, flexible LDPE and LDPE-melt-grafted nano-SiO_2 are used simultaneously to toughen and enforce brittle PPS. The impact strength of the composites was improved to 85.1KJ/m~2, which is 3.7 times of that of pure resin. The tensile and flexural strength was improved 27% and 9%, respectively. The formation of SiO_2-LDPE core-shell encapsulated structure and network structure with good interface adhesion in PPS matrix, and decrease of the size of spherilutes and crystallinity contributed the improvement of PPS.
引文
1．施良和，胡汉杰，高分子科学的今天与明天[M]，北京：化学工业出版社，1994年．
2．江明．高分子合金的物理化学[M]，成都：四川教育出版社，1985．
3．李玉林，何培新．高分子合金增韧机理的研究进展，高分子材料科学与工程，2002，18(5)，26-30．
4. A van der Wal, JJ Mulder, J Oderkerk, RJ Gaymans. Polypropylene-rubber blends: 1. The effect of the matrix properties on the impact behaviour, Polymer, 1998, 39(26), 6781-6787.
5. Mertz EH, Claver GC, Baer M. Studies on heterogeneous polymeric systems. J Polym Sci, 1956, 22: 325-341.
6. Bucknall C B, Smith R R. Stress whitening in high-impact polystyrene. Polymer, 1965,6 (8):437-446.
7. Bucknall C B, Clayton D, Keast W E. Rubber toughening of plastics, Part 2:Creep mechanisms in HIPS/PPO blends. J Mater Sci,1972,7 (12):1443-1453.
8. Bucknall C B, Clayton D. Rubber toughening of plastics. J Mater Sci,1972,7 (2):202-210.
9. Schrnitt J A, Keskkula H. Short time stress relaxation and toughness of rubber modified polystyrene. J Appl Polym Sci, 1960,3 (7):132-142.
10. Newman S, Strella S. Stress-strain behavior of rubber-reinforced glassy polymers. J Appl Polym Sci 1965;9:2297-2310.
11. Strella S. J Polym. Sci. A2, 1966, 3: 527-528.
12. Sue H, Huang J, Yee A F. Interfacial Adhesion and Toughening Mechanisms in an Alloy of Polycarbonate/Polyethylene, Polymer, 1992, 33:4868-4871.
13. Wu Souheng. Phase structure and adhesion in polymer blends: a criterion for rubber toughening. Polymer, 1985,26: 1855-1863.
14. Margolina A, Wu Souheng. Percolation model for brittle-tough transition in polymer blends. Polymer, 1988, 29, 2170-2173.
15. P.M. Ajayan, L.S. Schadler, P.V. Braun. Nanocomposite Science and Technology, Wiley 2003.
16. E.P. Plueddemann, Silane Coupling Agents, Plenum Publishing Corporation, 1991.
17. G. Wypych, Handbook of Fillers: Definitive User's Guide and Databook, Plastics Design Library, 1999.
18. Kurauchi T., Ohta T. Energy absorption in blends of polycarbonate with ABS and SAN. J Materi Sci, 1984, 19(5), 1699-709.
19. F. J. McGarry. Polymer composites, Annu. Rev. Mater. Sei. 1994.24:634.
20. Galeski, A., Strength and toughness of crystalline polymer systems. Progress in Polymer Science 2003, 28, (12), 1643-1699.
21. Liang, J. Z., Toughening and reinforcing in rigid inorganic particulate filled poly (propylene): A review. Journal of Applied Polymer Science, 2002, 83, (7), 1547-1555.
22．刘竞超，李小兵，张华林，等．纳米二氧化硅增强增韧环氧树脂的研究，胶体与聚合物，2000，18(4)，15-17．
23．欧玉春，于中振，方晓萍．界面改性剂对刚性粒子增韧尼龙6熔体流变行为的影响，高分子学报，1994(4)：449-454．
24．任显诚，白兰英，王贵恒．纳米级CaCO_3粒子增韧增强聚丙烯的研究．中国塑料，2000，14(1)：156．
25．黄锐，王旭，张玲，等．熔融共混法制备聚合物／纳米无机粒子复合材料，中国塑料，2003，17(4)，20-23．
26．王旭，黄锐．PP／纳米级CaCO_3复合材料性能研究，中国塑料，1999，13，22-25．
27．吴唯，徐种德．纳米刚性微粒与橡胶弹性微粒同时增强增韧聚丙烯的研究，高分子学报，2000，1，99-104．
28．宋波，黄锐，魏刚．纳米碳酸钙和马来酸酐接枝乙烯-辛烯共聚物弹性体对PA6脆韧转变及协同增韧的研究．合成橡胶工业，2004，27(1)，48．
29．苏新清，华幼卿，乔金梁，等．“salami”结构的丁苯胶粉／纳米碳酸钙复合粒子协同增韧聚丙烯，合成橡胶工业，2004，1．
30. Peggy Cebe. Review of recent developments in PPS. Polymers & Polymer Composites, 1995, 3(4), 239-249
31. Thomas J.G. Reisinger. Polymers of tomorrow, Advanced Materials & Processes of Ticona, 2002.
32．杨杰主编．聚苯硫醚树脂及其应用[M]，北京：化学工业出版社，2006年．
33．佟伟，杨杰．聚苯硫醚共混合金的研究进展，化学研究与应用，2002，14(6)，718-722．
34. Anon. Polycarbonate drives engineering plastics, Chemical Week, 2004, 166(17), 28.
35. Jonghan Choi, Soonho Lim, et al. Studies of an epoxy-compatibilized poly(phenylene sulfide)/polycarbonate blend, Polymer, 1997, 38(17):4401～4406.
36．何志敏，张大伦，张文栓，等．PPS／PA6合金的研究，工程塑料应用，2005，33(1)，4-6．
37. Akhtar, S.; White, J. L., Phase morphology and mechanical properties of blends of poly (p-phenylene sulfide) and polyamides. Polym Eng and Sci, 1992, 32(10), 690-698.
38．候灿淑，李继红，余自力等．PPS／PA-66共混物结构与性能的研究，高分子材料科学与工程，1998，14(1)，75-77．
39. Chen Zhaobin, Li Tongsheng, Yang, Yuliang, et al. Mechanical and tribological properties of PA/PPS blends, Wear, 2004, 257(7-8), 696-707.
40. Kubo K, Masamoto J, Dispersion of Poly (phenylene ether) in a Poly (phenylene sulfide)/Poly (phenylene ether)Alloy, Macromol Mater and Eng, 2001, 286, 555-559.
41. Kibe H, Irisawa, K, Kosaka, M, et al. On the effect of fillers upon the tdbological properties of polyphenylene sulfide, Research Reports of Kogakuin University, 2002,93, 1-10.
42．何志敏，张大伦，张文栓，等．聚苯硫醚／聚四氟乙烯复合材料的研究，塑料，2005，34(2)，59-62．
43. Laigui Yu, Shengrong Yang, Weimin Liu, et al. An investigation of the friction and wear behaviors of polyphenylene sulfide filled with solid lubricants, Polym. Eng. and Sci., 2000, 40(8), 1825-32.
44．龙盛如，黄锐，杨杰等．纳米CaCO_3／PPS共混物流变性能的研究，航空材料学报，2004，24(2)，36-39．
45．张文栓，罗运军，宋海香等．纳米SiO_2改性聚苯硫醚力学性能的研究，工程塑料应用，2003，3 1(8)，4-6．
46. Lu Dan, Mai Yiu-Wing, Li Robert K. Y., Ye Lin. Impact strength and crystallization behavior of Nano-SiOx/poly(phenylene sulfide) (PPS) composites with heat-treated PPS. Macromolecular Materials and Engineering, 2003, 288(9), 693-698.
47．杨杰，龙盛如，张东辰等．聚苯硫醚／氧化锌晶须复合材料的研究，工程塑料应用，2003，5，5-8．
48．陈广玲，杨杰，肖炜，李光宪．聚苯硫醚结构功能一体化纳米复合材料的研制，功能材料，2004，35，799-802．
1．季根忠，刘维民，齐陈泽，阎逢元．刚性粒子增韧聚合物机理研究，高分子通报，2005，1，50-54．
2．冯嘉春，陈鸣才．无机刚性粒子增韧高分子研究进展，中国塑料，2000，14(11)，10-15．
3. Fu, Q.; Wang, G, Polyethylene toughened by rigid inorganic particles. Polymer Engineering and Science 1992, 32, (2), 94-97.
4．任杰，郑震．弹性体与刚性粒子增韧聚合物的研究进展，建筑材料学报，1998，1(4)，354-358．
5. Dubnikova, I. L.; Berezina, S. M.; Antonov, A. V., The effect of morphology of ternary-phase polypropylene/glass bead/ethylene-propylene rubber composites on the toughness and brittle-ductile transition. J Appl Polym Sci, 2002, 85, (9), 1911-1928.
6. Zhang, L.; Li, C.; Huang, R., Toughness mechanism of polypropylene/elastomer/filler composites. J Polym Sci Part B Polymr Phys, 2005, 43, (9), 1113-1123.
7. Chen, J.; Wang, G.; Zeng, X.; Zhao, H.; Cao, D.; Yun, J.; Tan, C. K., Toughening of Polypropylene-ethylene Copolymer with Nanosized CaCO_3. J Appl Polym Sci, 2004, 94, 796-802.
1．王平华，严满清，唐龙祥．纳米粒子表面修饰与改性SiO_2纳米粒子表面接枝聚合，高分子材料科学与工程，2003，19(5)，183-186．
2．毋伟，陈建峰，邵磊，等．聚合物接枝改性超细二氧化硅表面状况及形成机理，北京化工大学学报，2003，30(2)，1-4．
3．吴春蕾．纳米SiO_2表面接枝改性及其聚丙烯复合材料的研究[D]．中山大学，博士学位论文．2002．
4．卢寿慈主编．工业悬浮液：性能，调制及加工[M]，北京：化学工业出版社，2003．
5. Simon Biggs, Janine L. Burns, Yao-de Yan, et al. Molecular weight dependence of the depletion interaction between silica surfaces in solutions of sodium poly(styrene sulfonate), Langmuir 2000, 16, 9242-9248.
6. G. H. Koendefink, G. A. Vliegenthart, S. G. J. M. Kluijtmans. Depletion-induced crystallization in colloidal rod-sphere mixtures, Langmuir, 1999, 15, 4693-4696.
7．王旭．聚合物基无机纳米粒子复合材料的研究[D]．四川大学，博士学位论文，2001．
8．黄锐，王旭，张玲，等．熔融共混法制备聚合物／纳米无机粒子复合材料，中国塑料，2003，17(4)，20-23．
1 郭涛，王炼石，何一帆．聚丙烯／弹性体，无机粒子三元复合材料的研究进展．塑料，2004，33(1)，36-40．
2 徐伟平，黄锐．聚合物／无机纳米粒子复合材料研究进展．中国塑料，1997，11(5)：15．
3 苏新清，乔金，华幼卿，等．具有包藏结构的三元聚丙烯纳米复合材料结构与性能关系的研究．高分子学报，2005，1，142-148．
4 Prephet K, Horanont P. Phase structure of ternary polypropylene/ elastomer/ filler composites: Effect of elastomer polarity. Polymer, 2000, 41:9283-9290.
5 毋伟，陈建峰，屈一新．硅烷偶联剂的种类与结构对二氧化硅表面聚合物接枝改性的影响．硅酸盐学报，2004，32(5)，570-575．
6 E. P. Plueddemann, Silane coupling agents. Plenum Publishing Corporation, 1991.
7 Frank Bauer, Horst Ernst, Ulrich Decker, et al. Preparation of scratch and abrasion resistant Polymeric nanocomposites by monomer grafting onto nanoparticles 1. Macromol Chem Phys, 2000, 201, 2654-2659.
8 冯嘉春，陈鸣才．无机刚性粒子增韧高分子研究进展，中国塑料，2000，14(11)，10-15．
9 Margolina A, Wu Souheng. Percolation model for brittle-tough transition in polymer blends. Polymer, 1988, 29, 2170-2173.
10 陈俊，杨伟，黄锐．纳米CaCO_3对PET／POE体系力学性能的影响．中国塑料，2005，19(2)，16-21．
11 袁绍彦，吕军，罗勇，黄锐．纳米碳酸钙／弹性体／聚苯乙烯体系的力学性能及形态．复合材料学报，2005，22(3)，25-29．
12 Minzhi Rong, Mingqiu Zhang, Yongxiang Zheng. Structure-property relationships of irradiation grafted nano-inorganic particle filled polypropylene composites. Polymer, 2001, 42, 167-183.
13 Wong W.K., Varrall D.C.. Role of molecular structure on the silane crosslinking of polyethylene. Polymer, 1994, 35(25), 5447-5452.
14 黄锐，王旭，张玲，等．熔融共混法制备聚合物／纳米无机粒子复合材料，中国塑料，2003，17(4)，20-23．
15 潘祖仁编．高分子化学[M]，北京：化学工业出版社，1996，33．
16 R·J·塞缪尔斯．徐振淼译．结晶高聚物的性质——结构的识别、解释和应用[M]，北京：科学出版社，1984．
17 Gupta A K, et al. Effect of addition of high-density polyethylene on the crystallization and mechanical properties of polypropylene and glass-fiber-reinforced polypropylene. J Appl Polym Sci, 1982,27(12), 4669-4686.
18 余坚．聚丙烯接枝马来酸酐及其离聚物的非等温结晶动力学，高分子学报，1999，5，513-519．
19 郭仁义，危大福，卢红，等．结晶促进剂和成核剂对PET结晶性能的影响．高分子材料科学与工程，2003，19(4)，121-124．
20 麦堪成，张声春，高庆福，等．聚苯硫醚／尼龙6共混物的结晶与熔融行为，高分子材料科学与工程，2000，16(3)，148-154．
21 郭刚，于杰，罗筑，等．纳米SiO_2粒子与聚烯烃弹性体协同改性聚丙烯的研究．现代化工，2004，24(7)，40-43．