端羧基聚乳酸共聚物的合成及表征  

Synthesis and characterization of carboxyl-terminated poly(lactic acid)

作　　者：樊国栋[1,2] 张春梅[1] 林振宇[2] 陈春兰[1] 杨锐[1] 李甜甜[1] 

机构地区：[1]陕西科技大学化学与化工学院,教育部轻化工助剂化学与技术重点实验室,陕西西安710021 [2]福州大学食品安全分析与检测技术教育部重点实验室,福建福州350002

出　　处：《功能材料》2011年第B06期541-543,548,共4页Journal of Functional Materials

基　　金：食品安全分析与检测技术教育部重点实验室(福州大学)开放基金资助项目(FS10003);陕西省教育厅重点实验室重点科研计划资助项目(09JS061)

摘　　要：以乳酸为原料,辛酸亚锡为催化剂,采用梯度升温法,在168℃、0.098MPa下直接熔融缩聚生成端羧基聚乳酸共聚物P(LA/SA)、P(LA/CA)和P(LA/AC)。用乌氏粘度法、FT-IR、1 H-NMR、DSC、TGA及XRD等对共聚物进行了表征。结果表明和PLA相比,3种端羧基共聚物Tg均有不同程度的降低,说明端羧基的引入降低了聚乳酸的刚性;TGA结果表明各共聚物热稳定性提高为一步热分解过程;XRD分析得出P(LA/SA)和P(LA/AC)比PLA的结晶度有所升高,而P(LA/CA)的结晶度略微降低,说明可通过调节乳酸和改性剂的配比来调节材料的力学性能。The carboxyl-terminated modified polylactic acid copolymers of P （LA/SA）, P（LA/CA） and P（LA/ AC） were synthesized via directly melt polycondensation with D, L racemic lactic acid （l）, L I.A） as raw materi al and stannous octoate as catalyst. The copolymerization reaction was performed at the temperature of 168 C and the pressure of 0. 098 MPa using linear heating method. The copolymers were characterized by viscosity av erage molecular weight, FT-IR, ~H-NMR, DSC, TGA and XRD. The results demonstrate that Tg of the car boxyl-terminated copolymers is lower than PLA, reducing the rigidity of PLA; the copolymers have good ther mal stability for one step thermal decomposition; compared with PLA, the crystallinity of P（I.A/SA） and P （LA/AC） decreased, while the P（LA/CA） slightly decreased, so that, by adjusting the ratio of lactic acid and modifier to adjust the mechanical properties.

关 键 词：聚乳酸 端羧基改性 梯度升温 直接熔融缩聚 

分 类 号：TQ316[化学工程—高聚物工业] O636.1[理学—高分子化学]