阻燃型桐酸-马来酸酐环氧固化剂的合成及性能研究

Study on the preparation and properties of flame retardant tung acid-maleic anhydride epoxy curing agens

由桐酸(TOA)经Diels-Alder加成反应制备得到桐酸-马来酸酐(TOMAH),再将TOMAH与9,10-二氢-9-氧-10-磷杂菲-10-氧化物(DOPO)由Michael加成反应制得阻燃型桐酸-马来酸酐固化剂(DOPO-TOMAH)。通过傅里叶红外光谱及核磁共振氢谱表征了产物的结构。将制得的TOMAH、DOPO-TOMAH和用作对比的桐马酸甲酯(TM)与环氧树脂反应得到固化材料。通过动态热力学分析、热重分析、极限氧指数测试和力学性能测试研究了不同环氧固化材料的性能。结果表明,由于有羧基和酸酐基团同时参与固化,TOMAH固化材料的玻璃化转变温度比TM固化材料高出近20℃。材料的阻燃性则随着DOPO含量的增加逐渐提高,而材料拉伸强度却随之下降。当DOPO的质量分数达到50%时,环氧固化材料的拉伸强度为35.18 MPa,极限氧指数为28,比未添加DOPO的固化材料提高了32.9%,属于难燃材料。

The tung acid-maleic anhydride（TOMAH） was prepared by Diels-Alder addition reaction using tung acid as raw material. Then the flame retardant epoxy curing agent （DOPO-TOMAH） was obtained by the Michael addition reaction of TOMAH and 9, lO- dihydro-9-oxa-10-phosphaphenanthren-10-oxide（DOPO）. The product structures were confirmed by FT-IR and 1H-NMR . The epoxy cured materials were prepared by curing the epoxy resins with the obtained TOMAH, DOPO-TOMAH and methyl eleostearate maleic anhydride adduct（TM）which was used for comparison. The properties of different epoxy cured materials were investigated by the DMA, TGA and testings of limiting oxygen index and mechanical properties. The results showed that the glass transition temperature of the TOMAH cured material was higher than that of TM cured material nearly 20 ℃ because the carboxyl and anhydride groups participated in the curing at the same time. The flame retardance of the material was gradually increased and the tensile strength was decreased with the increasing of DOPO contents. The tensile strength of the cured epoxy material with 50% DOPO was 35.18 MPa and the limiting oxygen index was 28, improved by 32.9% compared with those of cured materials without adding DOPO. It was belonged to the flame retardant materials.