Premium
Cure behavior of an epoxy–novolac molding compound
Author(s) -
Hsieh T. H.,
Su A. C.
Publication year - 1992
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.1992.070440118
Subject(s) - differential scanning calorimetry , materials science , epoxy , isothermal process , rheology , composite material , vitrification , glass transition , molding (decorative) , dynamic mechanical analysis , gel point , polymer chemistry , polymer , thermodynamics , medicine , physics , andrology
The isothermal cure of an epoxy–novolac molding compound was studied by means of differential scanning calorimetry (DSC). The glass transition temperature ( T g ) of the molding compound increased in an approximately linear manner with conversion (α) during the major part of the cure process. Predictions of an empirical kinetic scheme (established earlier from dynamic DSC results) compared favorably with the present isothermal results in the absence of vitrification. In combination with the gel point conversion (α gel ) determined via dynamic rheological analysis and gravimetric measurements, our DSC results indicated that gelation bears no apparent effect on the rate of cure whereas vitrification retards the cure reaction. Based on the measured α gel , the approximate T g −α relationship, and the thermokinetic results, the time–temperature–transformation diagram of this molding compound was constructed and discussed.