2019 Volume 73 Issue 1 Pages 148-154
A method to detect water absorption controlling material on mortar for setting wall tiles by TG-MS was researched. TG-MS was executed on two types of water absorption controlling materials respectively composed primarily of ethylene-vinyl acetate copolymer （EVA） and acrylate-styrene copolymer （ASt）, and their thermal decomposition characteristics were evaluated. A component with m/z of＝60, which was considered to be acetic acid, was formed by thermal decomposition of the EVA type material. A component with m/z of＝104, which was considered to be styrene, was formed by thermal decomposition of the ASt type material. These two components were found to be the characteristic components of each water absorption controlling material. Mortar samples were prepared by coating these water absorption controlling materials on mortar, and powders collected from the surfaces of these mortars were subjected to TG-MS. In the case of the ASt type material, styrene was also detected and it was determined to be the key component for detection of ASt type water absorption controlling material on a mortar. In the case of the EVA type material, acetone as well as acetic acid were detected and these two components were determined to be the key components for detection of EVA type water absorption controlling material on mortar.
