【作者】 许曼；

【导师】 陈汉佳；

【作者基本信息】 汕头大学 ， 应用化学， 2010， 硕士

【摘要】 聚丙烯( PP )是一种用途广泛的非极性结晶高分子材料,表面张力低,难以与其它极性介质相浸润。作为医用高分子材料,聚丙烯的非极性结构与生物体的结构相差甚远,与伤口接触会引起排异反应。同时,聚丙烯制品在应用的过程中,其高绝缘性也导致材料表面容易产生静电累积,产生静电危害,其抗菌性能也有待提高。因此,有必要对聚丙烯材料进行表面改性。通过在聚丙烯制品表面引入具有不同改性目的的功能性基团,可以改善其生物相容性、抗菌性、抗静电性能。同时,表面功能基团的引入,赋予聚丙烯以全新的性能,可以实现材料的功能化和高性能化,扩大其使用范围。本论文采用大分子表面改性剂与聚丙烯共混的方式,使聚丙烯表面功能化,达到改性的目的。具有良好表面迁移、富集特性的大分子表面改性剂,可以在很低的加入量下起到明显的表面改性效果,且不影响其本体性能。同时,与低分子量的表面改性剂相比,当制品表面受到冲刷作用时,这种添加剂较难脱离,具有一定的长效性。选择利用聚乙烯基吡咯烷酮(PVP)、聚丁二酸丁二醇酯(PBS)、聚3-羟基丁酸酯(PHB)作为大分子表面改性剂的功能性链段,以低分子量聚丙烯作为亲基体链段,通过低分子量端羧基聚丙烯链与端羟基功能性链段酯化的方法,合成了具有不同功效的嵌段共聚物作为大分子表面改性剂。通过红外测定和热重实验,研究大分子表面改性剂的组成、结构与耐热性能。利用合成的PP-b-PVP以及PP-b-PBS、PP-b-PHB作为大分子表面亲生物改性剂,分别添加于聚丙烯中制备改性薄膜。采用ATR-FTIR、接触角测定及SEM等手段,考察了不同的改性剂添加量对聚丙烯基体表面富集程度的影响,并对改性薄膜的血液相容性和组织相容性进行表征。实验表明,通过大分子表面亲生物改性剂的共混改性,可以显著提高聚丙烯表面的血液相容性和组织相容性,血小板粘附数量减小,血浆复钙时间延长、溶血率下降,其中尤以PP-b-PVP改性效果最好。另外,利用合成的PP-b-PQVP作为聚丙烯表面抗菌、抗静电改性剂,用ATR-FTIR和接触角测定等手段,考察了PP-b-PQVP的添加量对改性剂表面富集程度的影响,PP-b-PQVP作为大分子表面改性剂能够实现在聚丙烯表面的选择性富集,提高聚丙烯的表面抗菌活性和抗静电性能。由于大分子表面改性剂与基体不存在化学键,其改性效果的稳定性和持久性必须依靠改性剂的亲基体链段锚固于基体内部,才能改善改性的长效性。因此,本文还考察了改性材料的抗溶剂腐蚀性。与小分子表面改性剂相比,含有亲基体链段的大分子表面改性剂耐溶剂浸泡能力明显增强。更多还原

【Abstract】 Due to its low surface energy and relatively high crystallinity, products of polypropylene are hard to dye, adhere and coat. Its compatibility with polar polymers is also poor. As a medical polymer material, the non-polar structure of polypropylene is far different from the structure of organisms’, which causes the phenomenon of rejection when it contacts with the wounds. In addition, the material surface should avoid bacterial or fungal infections and the spread of disease, as well as to avoid the occurrence of electrostatic hazards in the application of polypropylene. To overcome these barriers,surface modification is frequently employed to enhance its surface performances.By introducing functional segments onto the surface, the biocompatibility, antibacterial and antistatic properties of polypropylene can be improved. Meanwhile, new surface performances of polypropylene can be achieved by introducing functional segments onto the surface, which can expand the scope of its application.Blending with macromolecular surface modifiers is often recognized as a potential technique to functionalize the surface of polypropylene. Modification by loading with macromolecular surface modifiers at very low content has a significant effect on the surface performance without affecting its ontology. Furthermore, compared with the low molecular weight surfactants, macromolecular surface modifiers are more difficult to be detracted from the surface when the products are frictionized or washed with water and organic solvents, which endows their lasting effectiveness.The aims of this dissertation are to synthesize the block copolymers suitable for surface modification of polypropylene and to evaluate the preferential segregation of additives on the surface of polypropylene blends. PP-b-PVP, as well as PP-b-PBS and PP-b-PHB used were synthesized through the esterification of dicarboxyl-terminated polypropylene with hydroxyl-terminated respective polymers. Their structures and thermal stabilities were characterized by IR, NMR and TGA. The surface enrichments of copolymers on polypropylene were evaluated by attenuated total reflectance IR Spectroscopy, contact angle measurements. The modified effects of biocompatibility were also characterized by determination of the extent of platelet adsorption, plasma recalcixcation time and hemolysis rate, cell proliferation using smooth muscle cells from rabbit aorta. The results revealed that the blood compatibility and cell compatibility of PP are improved significantly by entrapment of a few copolymers in PP.In addition, PP-b-PQVP was synthesized and used as a macromolecular surface modifier of polypropylene to enhance its surface antimicrobial and anti-electrostatic properties. The results of ATR-FTIR, contact angle measurement indicated that the additive can enrich on the surface of polypropylene and increase its antibacterial activity and anti-electrostatic property.The modifying durability was studied by the solvent-soaked experiments. Compared with the small molecule modifiers, the macromolecular surface modifiers exhibit better stability of resistant-solvent.更多还原