抗氧剂4010NA和RD对过氧化二异丙苯交联EPDM耐热复合材料性能的影响

Effect of Antioxidant 4010NA and RD on the Properties of EPDM Heat Resistant Composites Crosslinked by Dicumyl Peroxide

以三元乙丙橡胶(EPDM)为基体材料,过氧化二异丙苯(DCP)为主交联剂,制备一种EPDM耐热复合材料。从门尼黏度、硫化曲线、力学强度、热失重、热空气老化强度和红外光谱等方面,探究了N-异丙基-N’-苯基对苯二胺(4010NA)和2,2,4-三甲基-1,2-二氢化喹啉(RD)对材料工艺、力学和热学性能的影响。结果表明,防老剂含量为0~8 phr时,材料流动性能随4010NA增加明显降低,随RD增加变化不明显;拉伸强度随4010NA和RD增加逐渐减小,同等含量4010NA减小强度更为明显;适当含量的4010NA和RD明显提高EPDM橡胶热氧老化强度;相对于RD基EPDM橡胶,4010NA基EPDM橡胶的高温裂解和150℃×168 h热氧老化性能略低;4010NA/DCP热处理试样在1309 cm^-1处出现N-O伸缩振动峰,推断提高热氧老化作用的机理是基于N-O-C结构的捕捉氧气和生成自由基促进EPDM分子交联。

A heat-resistant composite of ethylene–propylene–diene monomer rubber(EPDM) was prepared. Dicumyl peroxide(DCP) was used as main crosslinking agent. Effects of N-isopropyl-N′-phenyl-p-phenylenediamine(4010 NA) and 2,2,4-trimethyl-1,2-dihydroquinoline(RD) on EPDM composites were investigated. Mooney viscosity, vulcanization curve, tensile strength, TGA, hot-air-aging strength and FT-IR were used to characterize the process, mechanics, thermal cracking, thermo-oxidative-aging properties of composites. The results show that with the increasing content of antioxidant from 0 phr to 8 phr, the fluidity decreases with 4010 NA while changing little with RD. The tensile strength decreases with 4010 NA and RD, while the same content of 4010 NA decreases the intensity more obviously. Appropriate 4010 NA and RD improve the thermal-oxygen-aging strength of EPDM significantly, while 4010 NA-based EPDM is slightly lower at both high-temperature-cracking and thermal-oxygen-aging properties of 150 ℃× 168 h than RD-based EPDM. Through FT-IR, the stretching vibration peak of N-O appears at 1309 cm^-1 in the heat-treated 4010 NA/DCP, and it can be concluded that the mechanism of improving the thermal-aging performance is that the N-O-C groups can capture oxygen and generate free radicals for crosslinking EPDM.