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Novel observations on kinetics of nonisothermal crystallization in fly ash filled isotactic‐polypropylene composites
Author(s) -
Nath Dilip Chandra Deb,
Bandyopadhyay Sri,
Yu Aibing,
Blackburn Darryl,
White Chris
Publication year - 2009
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/app.31186
Subject(s) - tacticity , materials science , differential scanning calorimetry , activation energy , crystallization , polypropylene , kinetics , composite material , phase (matter) , polymer chemistry , thermodynamics , polymer , polymerization , chemistry , physics , organic chemistry , quantum mechanics
A study on nonisothermal crystallization kinetics in fly ash (FA) filled isotactic ‐ polypropylene (PP) composites has revealed some interesting phenomena. Composites made by injection moulding of PP with 0, 20, 45, and 60 wt % of FA were nonisothermally studied using differential scanning calorimetry at cooling rates 10°C, 15°C, and 20°C per min from a melt temperature of 200°C cooled to −30 °C. Whilst neat PP showed a mono modal α crystalline phase‐ only structure, presence of FA led to bimodal thermographs revealing partial transcrystallisation of α into β, to maximum 14%. The onset and peak crystallization temperatures of all samples decreased by ∼ 3°C with each 5°C/min increase in cooling rate. Parameters such as crystal growth rate, dimensions, and activation energy were determined using a series of established models. The Avrami graphs showed that contrary to the published data, there are two sets of straight lines (a) with a lower slope at low cooling rate and (b) with a distinctly higher slope for high cooling rate. Activation energy of the materials reached a maximum at 45% FA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010