反应性挤出粉料PE接枝MA的研究

REACTIVE EXTRUSION IN MALEATION OF POVVDER POLYETHYLENE

在高速混合机中,均匀混合HDPE粉料、马来酸酐(MA)和过氧化二异丙苯(DCP),然后在单螺杆挤出机中,于180℃下熔融挤出反应,得到PE接枝MA(PE-MA)样品。反复用二甲苯溶解,经丙酮沉淀后,测得的红外光谱表明,如上处理2～3次可完全除去未反应的MA。经二次挤出,产物的接枝率(G_x)和熔融指数(MI)变化很小,说明一次挤出后PE-MA中无残留过氧化物。研究了G_x随DCP或MA用量的变化,得知采用MI高的HDPE有利于接枝反应。

Factors in realizing reactive processing in maleation of powder polyethylene (HDPE) in an extruder were studied. Removal of unreacted malcic anhydride (MA) from the extrudate was achived by precipitation of PE-MA in acetone from its xylene solution. Degree of grating of MA (Gr) increased with increase in melt index (Ml) of PE-MA in extrusion or with inceased Gx suggested the predominance of chanin coupling in the termination process. Ml and Gx vaulcs, which showed different dependency in series of fixed concentration of DCP or MA, could be adjusted at will in preparing PE-MA.