基于改性Silly Putty的新型加工助剂  

Novel Processing Aid Based on Modified Silly Putty

作　　者：刘海军（译） 

出　　处：《聚合物与助剂》2009年第2期24-36,共13页Polymer & Additives

摘　　要：组成和著名的SillyPutly相似，基于用硼酸固化的低分子量硅烷醇的一种粘弹体材料，在线型低密度聚乙烯（LLDPE）挤塑中，用来延迟鲨鱼皮和粘滑不稳定性的发生。配方中使用氢氧化钠和磷酸有助于增加材料对金属的粘附力，提高超过200℃时材料的效能。加入金属氧化粉末，如硼砂、硅石，特别是硅酸盐，更有助于延迟流动不稳定性。当这种材料用作ILDPE的添加剂（-0．1％）或挤塑模头的涂布时，用相同的螺杆挤塑机挤出时发现，由于鲨鱼皮不稳定性的迟延，挤出速率高出2535倍，压力减少了大约45％。对鲨鱼皮的起因和不稳定性的迟延，给出了试验性的解释。A viscoelastic material based on low - molecular - weight silanols cured by boric acid, i. e., having a composition similar to that of the well - known Silly Putty, was used to delay sharkskin and stickslip instabilities in the extrusion of linear low- density polyethylene（ELDPE）. The use of sodium hydroxide and phosphoric acid in the composition helped to improve adhesion of the material to metal and to extend its efficiency above 200℃. Adding powders of metal oxides, e. g., borax, silica, and especially silicates, further helped to delay the flow instabilities. A delay of the sharkskin instability to 25 - 35 times higher extrusion rates was achieved, and about 45 % less pressure was observed in a screw extruder at the same throughput when this material was used as an additives to LLDPE（ - 0.1% ） or as a coating of the extrusion die. Tentative explanations of the sharkskin origin and for the delay of the instability are proposed.

关 键 词：加工助剂 流动不稳定性 线型低密度聚乙烯 弹体材料 改性 金属氧化 挤出速率 鲨鱼皮 

分 类 号：TQ330.38[化学工程—橡胶工业] TL334[核科学技术—核技术及应用]