乙烯-乙酸乙烯酯共聚物/聚甲醛动态硫化热塑性弹性体的制备

Preparation of Ethylene-vinyl Acetate/Polyacetal Thermoplastic Elastomers

以1,1-二叔丁基过氧基-3,3,5-三甲基环己烷(Luperox231)/N,N’-间苯撑双马来酰亚胺(HVA-2)为硫化体系,采用反应挤出动态硫化法制备了乙烯-乙酸乙烯酯共聚物(EVA)/聚甲醛(POM)动态硫化热塑性弹性体。结果表明,EVA/POM动态硫化热塑性弹性体的综合力学性能明显改善,拉伸强度可达到12 MPa左右,但断裂伸长率较低;螺杆转速和挤出机加工温度对EVA/POM动态硫化热塑性弹性体的力学性能有影响,为制备性能良好的EVA/POM动态硫化热塑性弹性体,螺杆转速设定为250r/min,挤出机加工温度为145~175℃;Luperox231用量的增加使动态硫化热塑性弹性体的拉伸强度和断裂伸长率、永久变形以及肖D硬度均下降,而HVA-2用量的增加使动态硫化热塑性弹性体的拉伸强度和永久变形呈先降低后升高的趋势。

An ethylene-vinyl acetate/polyoxymethylene thermoplastic elastomer（TPV）was prepared by dynamic vulcanization method using Luperox231/HVA-2 mixture as a vulcanization system.Compared with classical EVA/POM blends,comprehensive mechanical properties of the TPV could be improved significantly,and its tensile strength reached around 12 MPa with low elongation at break.The experiments also suggested that screw speed and processing temperature of the extruder influenced mechanical properties of TPV.To prepare the TPV with good performance,the screw speed and temperature should be set at 250r/min and 145~175 ℃,respectively.The resultant TPV exhibited a decrease in tensile strength,elongation at break and D-Shore hardness with an increase of Luperox231 concentration,and however its tensile strength and permanent deformation presented a decreasing trend at first and then increasing with increasing concentration of HVA-2.