Extrusion of broad‐molecular‐weight‐distribution polyethylenes
Extrusion of broad‐molecular‐weight‐distribution polyethylenes
复制标题
宽分子量分布聚乙烯的挤出
DOI：
10.1002/pen.20254
复制
发表时间：
2004
影响因子：
3.2
通讯作者：
K. R. Slusarz
中科院分区：
文献类型：
--
作者：
R. Krishnaswamy;D. C. Rohlfing;A. Sukhadia;K. R. Slusarz
本文讨论了四种高分子量、宽分子量分布聚乙烯树脂的挤出（单螺杆）特性，着重讨论了挤出速率。尽管主题聚乙烯的分子量高，但它们的宽MWD（Mw/Mn范围：10至50）不限制挤出期间产生的压力和扭矩。然而，这四种聚合物的具体输出是相当不同的。首先，固体输送部分的动力学进行了检查，最高分子量的聚乙烯表现出较低的固体输送速率比其他三个。此外，提出了一种简单、快速的方法来评估各种聚乙烯的相对固体输送效率。最后，还解决了特定输出对聚合物的熔体流变学的依赖性;具体地，发现计量部分中熔体的剪切稀化程度影响输出速率。四种聚合物之一的剪切稀化特性的独特和违反直觉的温度依赖性也将在其挤出特性方面得到解决。Polym.工程科学44：2266-2273，2004.© 2004年塑料工程师协会。
The extrusion (single-screw) characteristics of four high-molecular-weight, broad-molecular-weight-distribution (MWD) polyethylene resins are discussed with an emphasis on the output rate. Despite the high molecular weights of the subject polyethylenes, their broad MWD (Mw/Mn range: 10 to 50) does not limit the pressure and torque developed during extrusion. However, the specific output of the four polymers was quite varied. First, the dynamics of the solids conveying section were examined with the highest-molecular-weight polyethylene exhibiting lower solids-conveying rate than the other three. Further, a simple and quick method to evaluate the relative solids-conveying efficiencies for various polyethylenes is presented. Finally, the dependence of the specific output on the melt rheology of the polymers is also addressed; specifically, the shear-thinning extent of the melt in the metering section was found to influence output rate. The unique and counterintuitive temperature-dependence of the shear-thinning character for one of the four polymers will also be addressed in relation to its extrusion characteristics. Polym. Eng. Sci. 44:2266–2273, 2004. © 2004 Society of Plastics Engineers.