Molecularly oriented, silane-crosslinked ultra-high-molecular-weight polyethylene molded article and process for preparation thereof
申请人:MITSUI PETROCHEMICAL INDUSTRIES, LTD.
公开号:EP0229477A2
公开(公告)日:1987-07-22
If ultra-high-molecular-weight polyethylene having an intrinsic viscosity (q) of at least 5 dug is grafted with a silane compound in the presence of a radical initiator and extrusion-molded and the extrudate is impregnated with a silanol condensation catalyst after or during drawing and is then exposed to water to effect crosslinking, there is obtained a novel molecularly oriented molded article in which increase of the melting temperature, which is not observed in conventional draw-molded or crosslinked molded articles of polyethylene, can be attained, and even if this molecularly oriented molded article is exposed to a temperature of 180°C for 10 minutes, the molded article is not fused but the shape is retained and even after this heat history, a high strength retention ratio can be maintained. In this draw-molded article, the adhesiveness and creep resistance are prominently improved while high elastic modulus and high tensile strength inherent to a draw-molded article of ultra-high-molecular-weight polyethylene are retained.
如果在有自由基引发剂存在的情况下,用硅烷化合物接枝本征粘度(q)至少为 5 dug 的超高分子量聚乙烯,然后进行挤压成型,并在拉伸后或拉伸过程中用硅烷醇缩合催化剂浸渍挤出物,然后将挤出物暴露在水中以实现交联,则可获得一种新型的分子定向模塑制品,在这种制品中,熔化温度可以提高、即使将这种分子取向模塑制品暴露在 180°C 的温度下 10 分钟,模塑制品也不会熔化,但形状会保持不变,而且即使经过这样的加热,也能保持较高的强度保持率。在这种拉伸模塑制品中,粘合性和抗蠕变性得到了显著改善,同时还保留了超高分子量聚乙烯拉伸模塑制品固有的高弹性模量和高拉伸强度。