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Factors affecting the durability of Ca‐complexed methylmethacrylate copolymer films containing CaO–SiO 2 –H 2 O macromolecules
Author(s) -
Sugama T.,
Kukacka L. E.,
Carciello N.,
Warren J. B.
Publication year - 1984
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.1984.070290918
Subject(s) - materials science , cement , ultimate tensile strength , copolymer , composite material , composite number , metal , macromolecule , carboxylate , chemical engineering , polymer , aqueous solution , bond strength , polymer chemistry , adhesive , chemistry , organic chemistry , metallurgy , layer (electronics) , biochemistry , engineering
A CaO–SiO 2 –H 2 O macromolecular–ionomer complex was found to be formed in the superficial layers of MMA–TMPTMA copolymer composite films made with filler containing hydraulic cement during exposure in an autoclave at temperatures up to 200°C. This complex acted to prevent the hydrothermal deterioration of the original composite films, which is important if the films are used as protective layers on metals. This complex also contributed significantly to hydrophobicity, a low energy surface, and less surface roughness, thereby lowering the intrinsic water permeability of the films. The glass transition temperature T g and the tensile strength of the complexed films increased with increasing concentration of the cement additive used as a source of Ca 2+ metallic ions, but they decreased when the cement concentration became excessive because of the chain enlargement caused by the growth of a large quantity of hydrated macromolecules. Ca 2− ions were found to migrate from the cement grains in an aqueous medium and to have a crosslinking function connecting the oxidized metal surfaces and the functional carboxylate groups located in the pendent parts of the polymer molecules. The resultant shear bond strength of metal‐to‐metal lap joint specimens after exposure for 3 days to water at 150°C was twice as high as that for the samples made without cement.