Premium
The effect of molding time and temperature on the modulus and glass transition of phenolics
Author(s) -
Landi V. R.,
Mersereau J. M.,
Dorman S. E.
Publication year - 1986
Publication title -
polymer composites
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.577
H-Index - 82
eISSN - 1548-0569
pISSN - 0272-8397
DOI - 10.1002/pc.750070304
Subject(s) - materials science , glass transition , composite material , modulus , dynamic mechanical analysis , curing (chemistry) , molding (decorative) , dynamic modulus , atmospheric temperature range , young's modulus , polymer , thermodynamics , physics
The effects of molding time and temperature on the dynamic mechanical behavior of a novolak phenolic molding compound were measured using the DuPont Dynamic Mechanical Analyzer. Large differences were found in the modulus‐temperature response over the range of curing times (10 to 1800 s.) and temperatures (132 to 218°C) employed. Glass transition temperatures increased well beyond cure temperatures at long cure times. In the asmolded condition, samples cured at lower temperature had higher room temperature modulus than those cured at higher temperatures, and the lower modulus corresponded to lower density. Postbaking by steps up to 232°C increased the glass transition above 280°C, and also served to normalize the modulus differences found in as‐molded samples.