摘要
采用动态硫化法制备了嵌段共聚聚丙烯(PP-b-PE)/三元乙丙橡胶(EPDM)热塑性硫化胶(TPV),研究了其力学性能、压缩永久变形的可逆回复、Mullins效应及微观形态。结果表明,当PP-bPE/EPDM质量比为30/70时TPV的综合性能较好;室温条件下压缩永久变形的可逆回复随TPV中橡胶相含量的升高而明显加快,且残余形变较小;提高温度可加速TPV永久变形的可逆回复,且高橡胶含量者的形变完全可逆。PP-b-PE/EPDM TPV的单轴循环拉伸中存在明显的Mullins效应,在同一拉伸比下,内耗和阻尼因子在第1次加载-卸载循环中即达到最大值,第2次循环拉伸时明显下降,但之后下降趋势减缓,应力最大值则呈现缓慢下降的趋势。提高树脂用量,动态硫化产物的最大应力、残余形变、内耗、应力软化因子和阻尼因子均明显升高。拉伸断面的场发射扫描电镜观察结果表明,橡胶相含量的提高赋予了TPV强的弹性回复能力。
Poly （ propylene-block-ethylene ） copolymer（PP-b-PE）/ethylene propylene diene monomer （ EPDM ） thermoplastic vulcanizates （ TPV ） were prepared by dynamic vulcanization , and the mechanical properties , reversible recovery of compression set , Mullins effect and micromorphology of the prepared TPV were investigated systematically.The results showed that the TPV had good properties when PP-b-PE/EPDM （ mass ratio ） was 30/70.At room temperature , with increasing EPDM content in TPV, the reversible recovery of compression set was accelerated , and the residual deformation was decreased; with increasing temperature , the recovery of compression set was sped up significantly , and the residual compression set of TPV with high EPDM content tended to zero.There was an obvious Mullins effect in the uniaxial cyclic stretch of TPV.At the same stretch ratio , the internal friction and loss factor went up to the maximum during the first loading-unloading cycle and decreased evidently during the second cycle but slightly afterwards , furthermore, the maximum stress exhibited a slow downtrend during the stretch cycles.With increasing resin content in TPV, the maximum stress, residual deformation , internal friction , degree of stress softening effect and loss factor increased obviously.The observation results of TPV fracture surface by field emission scanning electron microscope indicated that the increase of rubber phase in matrix enhanced the elasticity of TPV.
出处
《合成橡胶工业》
CAS
CSCD
北大核心
2014年第4期263-268,共6页
China Synthetic Rubber Industry
基金
山东省自然科学基金资助项目(ZR 2012 EMM002)
青岛市科技发展计划项目[12-1-4-3-(9)-jch]
山东省高等学校科技计划项目(J 12 LA 15)
关键词
嵌段共聚聚丙烯
三元乙丙橡胶
力学性能
压缩永久变形
Mullins效应
微观形态
poly （ propylene-block-ethylene ） copolymer
ethylene propylene diene monomer
mechanical property
compression set
Mullins effect
micromorphology
