α-羟基,ω-环氧基聚己内酯/环氧树脂复合体系的制备和耐热性能

Preparation and Thermal Properties of α-Hydroxy,ω-Epoxide Polycaprolactone/Epoxy Resin Composites

利用ε-己内酯的酶促开环聚合,合成了α-羟基,ω-环氧基聚己内酯低聚物(ETPCL);利用—OH与—NCO的亲核加成反应,通过聚氨酯途径合成了环氧基封端的聚己内酯接枝环氧树脂共聚物(PCL-g-GY250);将PCL-g-GY250与分子量较高的环氧树脂GT7071进行共混,通过胺类固化剂与环氧基团的固化反应制备了不同PCL-g-GY250含量的环氧树脂复合体系(PCL-g-GY250/GT7071);利用热失重分析(TGA)及在甲苯中的溶胀实验分别对复合体系的耐热性能和交联密度进行了表征。结果表明:随PCL-g-GY250含量的增加,体系的交联网络密度逐渐下降;PCL-g-GY250的引入,使得复合体系的耐温性能得到改善:当PCL-g-GY250与GT7071的质量比为4∶1时,固化体系的5%热失重温度(T5d%)可由纯环氧固化体系的145.0℃提高到216.3℃;尤其是纯PCL-g-GY250固化体系的T5d%更是达到293.9℃,相比纯环氧树脂固化体系提高了148.9℃。

α-Hydroxyl, ω-epoxide polycaprolactone oligomer （ETPCL） was synthesized from ε-capro- lactone monomer and glycidol via enzyme catalyzed ring-opening polymerization. Then ETPCL grafted epoxy resin copolymer （PCL-g-GY250） was synthesized via --OH and --NCO nueleophilic addition reaction through urethane route. Through directly blending PCL-g-GY250 and epoxy resin GT7071 having higher molecular mass, and curing them with amine curing agent, a series of epoxy resin com- posites （PCL-g-GY250/GT7071） containing different content of PCL-g-GY250 were prepared. The thermal degradation and cross-linking density of the amine-cured epoxy composites were investigated by thermogravimetry analysis （TGA） and swelling in toluene, respectively. The results show that the cross-linking network density decreased with increasing PCL-g-GY250 content. And from TGA analy- sis, it can be concluded that incorporating PCL-g-GY250 into the epoxy resin improved the thermal re- sistance of the composites. When the mass ratio of PCL-g-GY250 and GT7071 was 4 ： 1, the charac- teristic degradation temperature at 5% mass loss （Td^5% ） was increased from 145.0℃ of amine-cured epoxy to 216. 3℃ of amine-cured PCL-g-GY250/ GT7071. And Td^5% of amine-cured PCL-g-GY250 reached 293.9℃, which was 148.9℃ higher than that of amine-cured epoxy.