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Non‐isothermal crystallization kinetics of calcium carbonate‐filled β‐crystalline phase polypropylene composites
Author(s) -
Tjong Sie Chin,
Xu Shi Ai
Publication year - 1997
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/(sici)1097-0126(199709)44:1<95::aid-pi821>3.0.co;2-l
Subject(s) - crystallization , materials science , calcium carbonate , polypropylene , differential scanning calorimetry , polymer , phase (matter) , composite material , chemical engineering , isothermal process , polymer chemistry , chemistry , organic chemistry , thermodynamics , physics , engineering
The non‐isothermal crystallization behaviour of high purity β‐phase and α‐phase polypropylene (PP) and their calcium carbonate‐filled composites was investigated by means of differential scanning calorimetry. High purity β‐PP polymer was prepared by adding an effective β‐nucleator consisting of equal amounts of pimelic acid and calcium stearate. The crystallization temperature and crystallization rate coefficient of pure β‐PP polymer were considerably higher than those of the α‐PP polymer. This was due to the β‐PP polymer containing nucleating agents, which act as nuclei for β‐spherulites. The calcium carbonate content had little or no effect on the crystallization rate coefficient and Ozawa exponent of the β‐phase PP in the composites. On the other hand, the crystallization temperature, crystallization rate coefficient and Ozawa exponent of the α‐phase PP composites depended on the calcium carbonate loading. The effect of calcium carbonate additions on the crystallization of α‐PP and β‐PP is discussed. ©1997 SCI