聚外消旋乳酸在TDI中的扩链研究  

Synthesis of Poly(D,L-lactic Acid) Biodegradable Material through Direct Melt Polycondensation-Diisocyanate Chain Extension by TDI in Solution State

作　　者：汪朝阳[1] 赵耀明[1] 王浚[1] 侯晓娜[2] 

机构地区：[1]华南理工大学材料学院,广东广州510640 [2]华南师范大学化学系,广东广州510006

出　　处：《高分子材料科学与工程》2007年第2期84-87,共4页Polymer Materials Science & Engineering

基　　金：高等学校博士学科点专项科研基金资助课题(20050561020);广东省自然科学基金资助项目(020885);广东省自然科学基金博士科研启动基金资助(5300082)

摘　　要：2,4-甲苯二异氰酸酯在四氢呋喃中对外消旋乳酸直接熔融聚合的低分子量聚外消旋乳酸进行扩链,用-Mη、FT-IR、1H-NMR、DSC、XRD等对扩链产物进行表征。SnCl2催化、NCO/OH为2时,66℃回流反应60 min,可得M-η为扩链前3.04倍的可溶性聚乳酸类生物降解材料。扩链产物中NH和苯环的引入使Tg、Tm和结晶度等相应提高。但时间过长、NCO/OH过大时,易生成可溶性差的交联副产物,较多副产物的混杂会导致Tg和熔融热的降低。Using poly（D,L-lactic acid） （PDLLA） directly produced via melt polycondensation as prepolymer, TDI as chain extender, poly （D, L-lactic acid）s biodegradable material was synthesized through diisocyanate chain extension in THF solution. Catalyzed by SnCl2, under the condition of NCO/OH molar ratio 2.0, temperature 66 ℃and time 60 rain,M^-η of chain extension product （TDI-PDLLA） could be 3.04 times higher than before. TDI-PDLLA was characterized with FT-IR, ^1H-NMR, DSC and XRD. TDI-PDLLA has higher Tg, Tm, and crystallinity than prepolymer PDLI.A. However, cross-linking by-products with worse solubility in chloroform is apt to be produced once the reaction time is longer, or the molar ratio of NCO/OH is bigger. The existence of more cross-linking by：produCts made the Tg and melting heat of TDI-PDL- LA decrease.

关 键 词：聚外消旋乳酸 2 4-甲苯二异氰酸酯 溶液扩链 聚乳酸生物降解材料 

分 类 号：TB39[一般工业技术—材料科学与工程]