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Quiescent crystallization kinetics and morphology of isotactic polypropylene resins for injection molding. I. Isothermal crystallization
Author(s) -
De Carvalho B.,
Bretas R. E. S.
Publication year - 1998
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19980516)68:7<1159::aid-app13>3.0.co;2-t
Subject(s) - differential scanning calorimetry , polymer chemistry , polypropylene , materials science , maleic anhydride , crystallization , grafting , acrylic acid , kinetics , tacticity , isothermal process , polymer , morphology (biology) , chemical engineering , activation energy , polymer blend , composite material , polymerization , chemistry , copolymer , organic chemistry , thermodynamics , physics , genetics , quantum mechanics , biology , engineering
The quiescent isothermal crystallization kinetics of polypropylene was studied as a function of molecular weight ( M w ), amount of ethene, and amount of maleic anhydride and acrylic acid grafting. Differential scanning calorimetry and polarized light optical microscopy were used to follow this kinetics. It was observed that the linear growth rate, G , decreased with the increase of M w , but increased with the amount of ethene. In the grafted polymers, as the amount of grafting increased, G decreased. The fold surface free energy, σ e , was found to increase with the increase in M w . The heterophasic and grafted polymers had σ e values higher than the homopolymers. All samples showed spherulitic morphology, except the acrylic acid‐grafted polypropylene that showed axialitic morphology. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1159–1176, 1998