聚氨酯丙烯酸酯改性环氧树脂的结构与性能

Structure and Properties of Epoxy Resins Modified by Polyurethane Acrylate

通过自由基共聚反应合成了以甲基丙烯酸缩水甘油酯(GMA)、甲基丙烯酸羟丙酯(HPMA)、丙烯酸异辛酯(EHA)及苯乙烯(St)为单体的共聚物P(GMA-HPMA-EHA-St)(PGHES),用含异氰酸根的不饱和单体丙烯酸羟乙酯(HEA)-异佛尔酮二异氰酸酯(IPDI)对PGHES进行接枝改性得到得到含聚氨酯(PU)结构的聚丙烯酸酯共聚物PGHES-PUA。傅立叶红外光谱测试表明得到目标产物。用PGHES-PUA对环氧树脂(EP)进行改性,研究了体系的力学性能及热性能,结果表明,PGHES-PUA改性后的环氧树脂冲击强度提高,增韧改性效果较好,动态热机械分析(DMA)测试了体系的动态力学性能。热分析(DSC)和热重分析(TGA)表明体系的玻璃化转变温度及耐热性无明显变化。扫描电镜(SEM)分析表明PGHES-PUA在EP固化时发生微相分离。

A series of copolymers P（GMA-HPMA-EHA-St）（PGHES） were synthesized via free radical copolymerization with glycidylmethacrylate（GMA）,2-hydroxypropyl methacrylate（HPMA）,2-ethylhexyl acrylate（EHA）,and styrene（St）,and PGHES was modified with a prepolymer of half blocked IPDI-HEA which was synthesized using isophorone diisocyanate（IPDI） and 2-hydroxyethyl acrylate（HEA）,preparing copolymer PGHES-PUA.The FT-IR characterization reveals that the target product is obtained.Epoxy resin（EP） was modified by PGHES-PUA copolymers,and the mechanical and thermal properties of modified EP were studied.The results show that impact strength of modified EP significantly increases with increasing content of PGHES-PUA,which results in the good toughness of the modified epoxy resins.The behavior of the relaxation peaks was evaluated by dynamic mechanical analysis（DMA） and tried to explain the composition of networks.SEM micrographs present the phase separation,and the PGHES-PUA particles precipitate and distribute well in epoxy matrix.