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Effect of mold temperature on the morphology and properties of polypropylene: I. A propylene‐ethylene copolymer
Author(s) -
Henke S. J.,
Smith C. E.,
Abbott R. F.
Publication year - 1975
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760150205
Subject(s) - materials science , spherulite (polymer physics) , polypropylene , copolymer , composite material , ultimate tensile strength , ethylene , morphology (biology) , molding (decorative) , heat deflection temperature , mold , izod impact strength test , ethylene propylene rubber , polymer , organic chemistry , catalysis , chemistry , biology , genetics
The mechanical properties of a propylene‐ethylene copolymer resin depend strongly on the mold temperature employed during injection molding. Average spherulite size correlates well with most physical properties; good impact properties are related to small average size, and high heat distortion temperatures to large average size. Tensile specimens have three distinct regions when viewed through crossed polars. The outer region (Region 1) does not contain spherulites, but Regions 2 and 3 do. The largest spherulites are found in Region 3, the center of the specimen. Region 1 has a molecular weight higher than that of the other two regions.