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Isothermal crystallization of iPP in model glass‐fiber composites
Author(s) -
Janevski A.,
BogoevaGaceva G.
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(19980711)69:2<381::aid-app20>3.0.co;2-y
Subject(s) - composite material , materials science , crystallization , isothermal process , glass fiber , fiber , synthetic fiber , thermodynamics , physics
Isothermal crystallization of iPP in model glass‐fiber composites is studied by DSC, and the basic energetic parameters of crystallization are determined. Unsized untreated and thermally treated glass fibers are used in model composites to determine the role of the surface on nucleation and crystallization processes. Thermally treated glass fibers are found to exhibit a predominant nucleating effect as compared to unsized untreated ones, and the crystallization proceeds faster, resulting in lower values for the half‐time of crystallization (10–120 s). The energy of formation of a nuclei of critical dimensions at a given T c is also lower, and it decreases as the content of the fibers in the composite increases. The surface free energy of folding, σ e = 140 × 10 −3 J/m 2 , was determined for iPP in the composite containing 50% glass fibers, while for pure iPP, σ e = 170 × 10 −3 J/m 2 was found. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 381–389, 1998