TIME-TEMPERATURE-MISCIBILITY AND MORPHOLOGY OF POLYOLEFIN BLENDS

• 来源期刊: 高分子科学（英文版）
• 年，卷（期）: 2000,（3）
• 页码范围: 263-270
• 页数: 8页
• 语种: 英文

摘要

Miscibility and crystallization have been studied for polypropylene-polyethylene and polyethylene-polyethylene blends. In the case of the polypropylene blends the composition of interest is 20% polypropylene. At this composition the polypropylene has been found to be soluble in linear low density polyethylene but insoluble in high, low and very low density polyethylenes. The miscibility has been concluded from the crystallization kinetics and polarised optical microscopy with a hot stage. Polyethylene-polyethylene blends have been formed from polymers with similar average branching content but where they have different melting temperatures. Important consequences are to introduce long branches into a polyethylene that only has short branches, and to modify the morphology of a polyethylenes so that haze, gloss and strain hardening are improved. Polyethylene blends must be developed after careful consideration of the branch content and distribution within each of the constituents. It is not sufficient to simply blend polyethylenes, with the desired range of properties, without regard to the miscibility of the blend composition.