ABS/NBR TPV压缩永久形变的可逆回复机制及模型构建

采用动态硫化法制备了丙烯腈-丁二烯-苯乙烯三元共聚物(ABS)/丁腈橡胶(NBR)动态硫化体系,研究了橡塑比和热处理温度对压缩永久形变的可逆回复的影响,探讨了可逆回复的机制并构建其数学模型。结果表明,提高橡塑比和热处理温度,均可显著加快热塑性硫化胶(TPV)压缩永久形变的可逆回复,且在接近基体玻璃化转变温度(Tg)时TPV压缩永久形变几乎完全可逆;基于TPV的微观结构和可逆回复曲线的特征,探讨压缩永久形变的可逆回复机制;采用广义Maxwell模型对压缩永久形变可逆回复过程进行了描述,并探讨了橡塑比和热处理温度对可逆回复各阶段松弛时间的影响。

Mechanism and model construction of compression set reversible recovery of ABS/NBR thermoplastic vulcanizate

Thermoplastic vulcanizate（TPV）based on acrylonitrile-butadiene-styrene（ABS）/nitrile butadiene rubber（NBR）blends were prepared by dynamic vulcanization,and the influences of blending ratio and heat-treatment temperature on the reversible recovery of compression set,together with the mechanism and model construction of the reversible recovery of the TPV,were investigated systematically.Experimental results indicated that increasing the NBR content in TPV and increasing heattreatment temperature would lead to the fast recovery of compression set;moreover,the TPV had fully reversible deformation ability when the heat-treatment temperature was close to the Tgof ABS.The reversible recovery mechanism was discussed based on the characteristics of TPV microstructure and the reversible recovery curves of compression set.The generalized Maxwell model was used to describe the process of compression set recovery and the influences of blending ratio and heat-treatment temperature on the relaxation time in each stage of the recovery course were discussed.