同向双螺杆捏合盘厚度对MAH接枝LDPE反应挤出过程的影响

研究了同向双螺杆挤出机中,捏合盘元件的不同厚度对低密度聚乙烯(LDPE)接枝马来酸酐(MAH)反应挤出过程的影响,并将其与常规螺纹元件进行对比。对挤出沿程中的3个位置和挤出机出口处进行取样,用滴定法测定这些样品的接枝率。结果表明,捏合盘元件所对应的样品接枝率高于常规螺纹元件,并且随着捏合盘厚度的增加,其所对应的样品接枝率下降。此外对于接枝反应而言,捏合盘元件的分布混合能力所起到的作用要高于其分散混合能力。

Influence of the Thickness of Kneading Blocks on the Reactive Extrusion for LDPE-g-MAH

Comparing with the normal screw element,the influence of various thicknesses of kneading blocks in the co-rotating twin screw extruder on the reactive extrusion for LDPE-g-MAH was investigated.Sampling was performed from three positions along the extrusion and the exit of the extruder,and the grafting degree of these samples was confirmed by the method of titration.According to the results,the grafting degree of the samples for the kneading blocks was higher than that for the normal screw element,and with the increase of the thickness of the kneading blocks,the grafting degree of the samples declined.Moreover,as to the grafting reactive extrusion,the effect of the distributive mixing property for the kneading blocks was greater than that of the dispersive mixing property.