挤出级SAN/ASA共混物在毛细管流变仪中的熔体破碎现象  

Melt Fracture of Extrusion SAN/ASA Blends in Capillary Flow

作　　者：单桂芳 张军[2] 程冬霞[2] 周霆 罗明华 辛敏琦 

机构地区：[1]上海锦湖日丽塑料有限公司,上海201107 [2]神龙汽车有限公司,武汉430056

出　　处：《工程塑料应用》2014年第4期46-50,共5页Engineering Plastics Application

摘　　要：通过毛细管流变仪系统表征了挤出级苯乙烯–丙烯腈塑料与丙烯腈–苯乙烯–丙烯酸酯塑料(SAN/ASA)共混物的熔体破碎现象,研究了加工温度、SAN分子量及其AN含量、ASA分子量和ASA含量对ASA挤出物表面质量的影响。研究发现,随着SAN分子量的增加、SAN中AN含量的增加和ASA分子量的增加,引起聚合物发生熔体破碎的剪切速率(临界剪切速率)都有所减小,更容易出现不稳定挤出和熔体破碎现象;同时,随着SAN分子量的下降,ASA树脂的粘流活化能增加,熔体黏度的温度敏感性增加。随着ASA含量的增加,临界剪切速率亦移向低值区,熔体破碎现象与熔体加工过程储存的弹性能有关。此外,加工温度的提高有利于消除熔体破碎现象。Melt fracture of extrusion styrene-acrylonitrile plastic（SAN） / acrylonitrile-styrene-acrylate plastic（ASA） blends was studied by using capillary rhemoter. The effects of the processing temperature, the molecular weight of SAN, the AN content in SAN, the molecular weight and content of ASA on the surface quality of the ASA product were investigated. The results show that the critical shear rate（the shear rate at which the melt fracture occurs is denoted as the critical shear rate） is lowered with the increase of the molecular weight of SAN matrix, the AN content in SAN and the molecular weight of ASA. Also, decreasing the molecualr weigth of SAN matrix results in the increase of the flow actication energy of the blends, indicating the temperature sensitivity of shear viscosity increases with the decrease of molecular weight of SAN matrix. The critical shear rate is also moved toward to a low value with increasing the content of ASA, indicating that the melt fracture phenomenon of SAN / ASA blends is related to the magnitude of storaged elastic energy of the SAN / ASA blends melt during the extrusion process in capillary rhemoter. In addition, increasing the processing temperature can decrease or eliminate the melt fracture behavior of the SAN/ASA blends melt partially.

关 键 词：丙烯腈-苯乙烯-丙烯酸酯塑料 苯乙烯-丙烯腈塑料 熔体破碎 临界剪切速率 挤出级 

分 类 号：TQ050.425[化学工程]