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>Factors affecting the durability of Ca‐complexed methylmethacrylate copolymer films containing CaO–SiO2–H2O macromolecules
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Factors affecting the durability of Ca‐complexed methylmethacrylate copolymer films containing CaO–SiO2–H2O macromolecules
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机译：Factors affecting the durability of Ca‐complexed methylmethacrylate copolymer films containing CaO–SiO2–H2O macromolecules
AbstractA CaO–SiO2–H2O 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 temperatureTgand the tensile strength of the complexed films increased with increasing concentration of the cement additive used as a source of Ca2+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. Ca2−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
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