可控流变共聚PP的制备工艺及力学性能

用可控流变法降解共聚聚丙烯(PP)获得可控流变共聚PP。考察了基础树脂、过氧化物加入量、工艺参数对最终产品力学性能的影响。研究发现:在QP73N加入少量过氧化物便能显著改善流动性;根据基础树脂和最终产品的熔体流动指数可确定过氧化物的加入量;各种工艺参数对流变性能的影响由大到小依次为:温度、喂料转速、主机转速;喂料转速与主机转速之比越小,熔体流动指数越高;对降解产品力学性能的各项指标影响最大的因素都是挤出温度,其次是喂料转速和主机转速。

Manufacturing procedure and mechanical properties of controlled-rheological polypropylene copolymer

The controlled-rheological polypropylene is manufactured with the method of controlled-rheological degra- dation.In this paper,the mechanical properties of the final product,influenced by the basic resin,the peroxide concen- tration and different process conditions,is investigated.The investigation shows that high fluidity can be obtained with a small amount of peroxide added in QP73N.Mixing amount of peroxides can be measured by the original resin's MFI and the degradated product's MFI.The investigation also shows that temperature is the most important factor that influences the fluidity of degraded products,and other factors can be sequenced as the material feeding rotation speed and the screw rotation speed.At each fixed extrusion temperature,the less the ratio between the materials feeding rotation speed and the screw rotation speed is,the higher the MFI is.The extrusion temperature is the most important factor that influences the mechanical properties of the degradated products,and other factors can be sequenced as the material feeding rotation speed and the screw rotation speed.