【作者】 寇琴；

【导师】 高勤卫；

【作者基本信息】 南京林业大学 ， 化学工艺， 2008， 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,是一类重要的环境友好高分子材料,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。但聚乳酸也存在亲水性差、缺乏细胞识别信号、细胞亲和性差等缺陷。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。目前,国内外已有氨基酸及合成肽链改性聚乳酸材料的报导,但尚无以天然丝蛋白肽链改性PLA的报导。本论文以D,L-丙交酯和蚕丝丝素蛋白肽链（SF）为原料,锡盐/质子酸体系为催化剂,聚合制备丝蛋白肽链/D,L-乳酸共聚物（PSFLA）,并采用粘度法、旋光法、红外光谱法、差示扫描量热法、广角X衍射法、热重分析、扫描电镜、¹H核磁共振等方法对所得PSFLA的分子量、光学活性、微结构、热性能等进行了详细的研究,探讨了反应时间、反应温度、催化剂种类、催化剂用量、催化剂配比等反应条件对PSFLA的结构与性能的影响。以氯化亚锡/对甲苯磺酸作为催化剂时,可以制备得到嵌段的PSFLA,且D,L-丙交酯与SF投料比对PSFLA的粘均分子量、光学活性和分子链的组成均有影响,其中DLLA/SF为6/1和10/1均可以制备较高分子量的PSFLA。以氯化亚锡/萘二磺酸作为催化剂时,PSFLA的特性粘数和组成随反应时间、反应温度、催化剂用量以及催化剂配比而改变。在反应时间10小时、反应温度170℃,D,L-丙交酯/SF比值10/1、SnCl₂用量0.50 wt%、SnCl₂/萘二黄酸摩尔比为1/1、真空度—0.1Mpa时,可以制备具有一定特性粘数和晶态结构的PSFLA嵌段共聚物。以辛酸亚锡/萘二磺酸作为催化剂时,PSFLA的特性粘数和组成也同样随着反应时间、反应温度、催化剂用量以及催化剂配比而改变。在反应时间8小时、反应温度170℃、D,L-丙交酯/SF比值为10/1时、用量0.50 wt%、Sn（Oct）₂与萘二黄酸的摩尔比为1/1、真空度—0.1Mpa时,可以制备较高特性粘数的部分结晶的PSFLA嵌段共聚物。总之,本论文以D,L-丙交酯和丝素蛋白为原料,以锡盐/质子酸体系为催化剂,采用熔融开环共聚法成功合成了PSFLA,为PLA的改性提供了新的方法,所得到的共聚物可用于生物医用材料。该研究目前尚未见报道。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. 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 of silkworm is not only in rich in our country, but also having good cell affinity to the human cell. It can be used to modify the poly（lactic acid） material to improve the biodegradability of the material. There are many researches on the modification of poly（lactic acid） with aminophenol and synthetical peptide, but there aren’t any on modifing the modification of PDLLA by inartificial silk fibroin peptide chain so far.In this paper, silk fibroin/PLA is prepared through ring-opening copolymerization of D,L-lactide with silk fibroin. Viscometry, polarimetry, FT-IR, differential scaning calorimetry, X-ray diffraction, thermogravimetry, scanning electron microscopy and ¹H nuclear magnetic resonance are employed for the characterization of polymers obtained. The effects of reaction time, temperature, weight of catalyst, molar ratio of two catalysts were detected.Segment PSFLA can be prepared through SnCl₂/TSA. The molecular weight, optical activity and compose of PSFLA will change with the six different delivery quality proportion. The catalyst system of D,L-lactide/ silk fibroin 6: 1 and D,L-lactide/ silk fibroin 10:1 can be used to prepare PSFLA with high molecular weight.The molecular weight and compose of PSFLA will change with the reaction conditions. PSFLA with higher viscosity can be prepared with SnCl₂/naphthalene disulfonic acid as catalyst in following conditions: reaction time 10 hours, temperature 170℃, SnCl₂ 0.5wt%, molar ratio of SnCl₂/ naphthalene disulphonic acid 1:1, and vacuum -0.1 MPa. PSFLA with higher viscosity can be prepared with Sn（Oct）₂/naphthalene disulfonic acid as catalyst in following conditions: reaction time 8 hours, reaction temperature 170℃, SnCb 0.5wt%, molar ratio of SnCl₂/ naphthalene disulphonic acid 1:1, and vacuum -0.1 MPa.PLA with high optical activity can be prepared through D, L-lactide catalyzed by Tin salt and proton acid systems, which will deduce PLA cost and lessen the pollution of solvents during its process.更多还原