研究了聚烯烃/聚对苯二甲酸乙二酯（PET）共混物的微纤形成、制备工艺条件、连续相聚烯烃的选择和力学性能。用单螺杆挤出机挤出嵌段共聚聚丙烯（PP-B）/PET和高密度聚乙烯/PET时，挤出产物中会形成部分短而粗的微纤；采用“熔融挤出—热拉伸—淬火”工艺制备的PP-B/PET共混物中会生成更多长径比较大的PET微纤，且随拉伸比的增加，微纤数量增多，长径比增大，共混物的熔体流动速率降低；在挤出工艺条件下，最适合的连续相是PP-B，最适宜的工艺条件是：从进料口到机头温度分别为220，250，260，220℃，螺杆转速为50r/min，拉伸比为3；PP-B/PET原位微纤共混物的拉伸屈服应力比纯PP-B提高约33%；增大拉伸比可提高共混物的拉伸屈服应力和抗冲击性能。%The formation of micro-fibril,preparation conditions,continuous phase choice of polyolefin kinds and mechanical properties of polyolefin/polyethylene glycol terephthalate(PET)micro-fibril blends were studied. Part of short and thick micro-fibril were formed in the extrudates when block polypropylene(PP-B)/PET and high density polyethylene/PET were extruded by single screw extruder. More PET micro-fibril with large length-diameter ratio were produced through melting extrusion-hot stretching-quenching processing in PP-B/PET blends;both the number and the length-diameter ratio of the micro-fibril increased,and the melt flow rate of the blends decreased with the enlargement of the draw ratio. The most suitable continuous phase was PP-B in the condition of extrusion process. The optimum process conditions were as follows:the barrel temperatures from die to head were 220,250,260,220 ℃,the screw speed was 50 r/min,and the draw ratio was 3. The tensile stress at yield of PP-B/PET in-situ micro-fibril blends increased by approximately 33% compared to that of PP-B. The tensile stress at yield and the impact performance of the blends were improved with the enhancement of the draw ratio.
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