超高相对分子质量聚乙烯固相挤出过程研究

采用一种新型超高相对分子质量聚乙烯成型技术—固相挤出成型。采用扫描电子显微镜观察了制品成型前后内部微观结构变化；采用差示扫描量热分析，研究了不同挤出温度与口模拉伸比对挤出制品热性能的影响。结果表明，相对熔融挤出成型，固相挤出成型制品光滑、透明、密度较大；制品内部产生大量的微纤结构，结晶度提高，分子链取向增强，拉伸强度提高了2.7～4.5倍，拉伸弹性模量提高了42倍；另外，熔点上升了3～5 ℃、熔融焓及结晶度分别提高了8~10个百分点。

Study on Solid state Extrusion Technology of Ultra High Molecular Weight Polyethylene

A new extrusion technique, solid state extrusion was adopted for molding ultra high molecular weight polyethylene(PE-UHMW). The product by solid state extrusion was smoother, more transparent, and with a higher density than those based on regular extrusion. The microstructure of the products were studied using scanning electron microscope (SEM), and the effects of extrusion temperature and extrusion draw ratio on products’ thermal property were investigated using differential scanning calorimetry (DSC). It was found that a large quantity of micro-fiber was produced in the products of solid state extrusion. Compared with those by regular extrusion, it possessed a greater degree of molecular orientation, higher degree of crystallinity, and higher melting point. Besides, the tensile strength and modulus increased by 4 and 40 times based on regular extrusion ones.