聚乳酸基热固性聚氨酯及其形状记忆性能

Synthesis and characterization of polylactide-based thermosetting polyurethanes with shape memory properties

摘要:

通过聚乳酸二元醇和聚乳酸-聚己内酯共聚物二元醇与六亚甲基二异氰酸酯 (HDI) 三聚体交联反应合成了一系列生物基热固性聚氨酯 (Bio-PUs)。利用傅里叶红外 (FTIR)、差示扫描量热分析 (DSC)、热失重分析 (TGA)、万能拉伸机和细胞毒性等测试方法对获得的聚乳酸基聚氨酯进行了表征。结果表明，与聚乳酸二元醇相比，聚乳酸-聚己内酯共聚物二元醇降低了生物基热固性聚氨酯的玻璃化温度 (Tg)，提高了热固性聚氨酯的热稳定性；且聚乳酸-聚己内酯型聚氨酯的力学性能和形状记忆性能更为优异。其中，聚乳酸-聚己内酯共聚物二元醇分子量为3 000时得到的热固性聚氨酯 (Bio-PU2-3000) 的杨氏模量为277.7 MPa，伸长率为230%；聚乳酸-聚己内酯共聚物二元醇分子量为1 000得到的热固性聚氨酯 (Bio-PU2-1000) 在人体体温下的形变回复时间仅为93 s。另外，通过显微镜观察到细胞在含聚乳酸基热固性聚氨酯的培养液中生长状态良好，表明制备得到的生物基聚氨酯无细胞毒性。

Abstract:

A series of bio-based thermosetting polyurethanes (Bio-PUs) were synthesized by the crosslinking reaction of polylactide and its copolymers diols with hexamethylene diisocyanate (HDI) trimer. The obtained Bio-PUs were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TGA), universal tensile testing machine and cytotoxicity test. Results indicate that the PLA copolymer (P(LA-co-CL)) diols reduced the glass transition temperature (Tg) of Bio-PUs and improved their thermal stability, compared with PLA diols. The Bio-PUs synthesized from P (LA-co-CL) diols exhibit better mechanical performance and shape memory properties. Especially, Young modulus and elongation at break of the obtained Bio-PUs were 277.7 MPa and 230% respectively; the shape recovery time of the obtained Bio-PUs at body temperature was only 93 s. Furthermore, alamar blue assay results showed that the obtained Bio-PUs had no cell toxicity.