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The effect of the prepolymer composition of amino‐hardened epoxy resins on the water sorption behavior and plasticization
Author(s) -
Carfagna C.,
Apicella A.,
Nicolais L.
Publication year - 1982
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.1982.070270112
Subject(s) - epoxy , glass transition , plasticizer , diglycidyl ether , materials science , triethylenetetramine , polymer , prepolymer , polymer chemistry , bisphenol a , chemical engineering , curing (chemistry) , composite material , organic chemistry , chemistry , polyurethane , engineering
The main role of the amino hydrogen bonding in the plasticization of water‐penetrated epoxy resins has been tested on a diglycidyl ether of bisphenol‐A (DGEBA) epoxy cured with different amounts of triethylenetetramine (TETA). Samples were characterized both by calorimetric and moisture diffusion techniques. The increased water solubilities and glass transition temperature depressions observed for the samples cured with an increased content of amino hardener were attributed to the high hydrophilic character of the amine. Theoretical models, based on the analysis of the free volume and entropy of the water saturated polymer, have been used to test the nature of the polymer‐diluent interactions. The comparison between the experimentally determined and theoretical values of the wet glass transition temperatures indicates how the free volume better describes the behavior of the low amino content resins while the entropy model become effective at increasing amino contents. Moreover, the actual water solubilities have been determined by thermal cycling of water‐saturated samples of different composition and used in the cited models.