【作者】 查震源；

【导师】 高勤卫；

【作者基本信息】 南京林业大学 ， 材料加工工程， 2010， 硕士

【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。更多还原

【Abstract】 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.更多还原