PP对PBT/POE-g-MAH共混体系相形态和力学性能的影响

将聚丙烯(PP)与官能化聚烯烃弹性体(POE-g-M AH)共混,制备出4种新型增韧改性剂,研究了PP的含量和种类对PBT/POE-g-M AH共混体系相形态和力学性能的影响。SEM观察发现,新型增韧改性剂作为分散相具有以POE-g-M AH为软壳、PP为硬核的包藏结构。随着高熔体流动指数PP(EPF 30R)含量的增加,软壳层厚度逐渐减小,包藏结构分散相的相畴尺寸略有减小,分布更加均匀。但添加低熔体流动指数PP(EPS30R)后,包藏结构分散相的相畴尺寸变大,分布不均匀。力学性能测试表明,适量高熔体流动指数PP与POE-g-M AH并用具有显著的协同增韧作用。与PBT/POE-g-M AH体系相比,在相同的增韧剂总用量时,共混物在保持超高韧性的同时,拉伸强度损失最小。

Effect of Addition of Polypropylene on Morphology and Mechanical Properties of PBT/POE-g-MAH Binary Blends

Four types of novel impact modifiers were prepared by melt blending polypropylene(PP) with maleic anhydride-grafted ethylene-octene copolymer(POE-g-MAH).Effect of content and kinds of polypropylene on morphology and mechanical properties of PBT/POE-g-MAH binary blends was studied.Morphological observations indicate a morphology with rigid core of polypropylene embedded in soft shell of POE-g-MAH for novel impact modifiers as dispersion phase in matrix.As the increase of PP(EPF30R) with high melt-flow index,thickness of soft shell decreases gradually,size of the unique dispersion phase becomes smaller slightly and size distribution becomes narrower.However,size of the unique dispersion phase becomes larger and its distribution becomes uneven as addition of PP(EPS30R) with low melt-flow index into POE-g-MAH.The mechanical properties testing indicates that incorporation of PP(EPF30R) with high melt-flow index into POE-g-MAH has significantly synergistic toughening effect on PBT.Compared to PBT/POE-g-MAH birnary system,the PBT/POE-g-MAH/PP ternary blend obtains the same super-toughness and the loss of tensile strength is least as well when the same total amount of impact modifier is used.