关键词: 乙烯一醋酸乙烯酯, 可再分散乳胶粉, 性能, 喷雾干燥, 温度

Abstract:

Re-dispersible ethene-vinylacetate (EV A) polymer powders were prepared by means of spray drying , with polyvinyl alcohol (PV A) as the protective colloid and silica sol and inorganic powders as the anti -agglomerating agents. Then , the influence of the inlet and outlet temperatures on the performances of the prepared powders was investigated. Experimental results show that the inlet and outlet temperatures greatly influence the appearance ,water content , fluidity , stacking density , re-dispersibility , film performance and storage stability of the polymer powders , and that the water content and the stacking density decrease while the fluidity improves when increasing the inlet and outlet temperatures. It is also found that the appropriate inlet and outlet temperatures for spray drying are respectively 150 - 180℃ and 75 - 80 ℃, and that giving higher inlet temperature may result in the structure change of the powders. Moreover , the FfIR spectrum indicates that the mo1ecu1ar structure of the polymer powders after the spηdrying keeps unchanged at an inlet temperature of 180 ℃ .

Key words: ethene-vinyl acetate, re-dispersible polymer powder, performance, spray drying, temperature