异氰酸酯官能化二元乙丙橡胶的制备与表征

Isocyanate Functionalization of Ethylene Propylene Copolymer: Preparation and Characterization

以过氧化二异丙苯 (DCP)为引发剂 ,3 异氰酸酯基 4 甲苯氨基甲酸烯丙酯 (TAI)为接枝单体 ,对二元乙丙橡胶 (EPM )进行了自由基接枝官能化 ,产物用傅立叶红外光谱仪和旋转流变仪进行了表征 ,并用化学滴定法对接枝率进行了测定 .实验结果表明 ,影响接枝率的主要因素为引发剂和单体的浓度 ,反应时间及温度 ;官能化乙丙橡胶的重均分子量虽然比未官能化的乙丙橡胶增加了两倍左右 ,但没有发现凝胶 ;接枝产物与金属铝的粘结性明显提高 .

Ethylene propylene copolymer (EPM) is functionalized with isocyanate bearing unsaturated monomer, allyl (3 isocyanate 4 tolyl) carbamate(TAI), using dicumyl peroxide(DCP) as free radical initiator in xylene solution. Effects of the amounts of DCP and TAI, reaction time and temperature on the grafting degree (GD) are investigated systematically. The results show that by optimization of the functionalization conditions, the products grafted by isocyanate group (NCO) with content of TAI up to 6wt% can be obtained without gelation. FT IR is used to confirm the formation of EPM g TAI. The peak at 2 273 cm -1 , characteristic of NCO groups of EPM g TAI, reveals the evidence of grafting occurrence, the grafting degree is determined by chemical titration. Rheological behavior of both EPM g TAI and EPM is investigated by using a rotational rheometer. The apparent viscosity of EPM g TAI is higher than that of EPM. Adhesive property of EPM g TAI with aluminum foil is studied. The peeling strength between EPM g TAI plate and aluminum foil is enhanced dramatically.