核壳型复合乳胶膜干燥速率的研究

Study on Drying rate of P(St-co-BA)/P(MMA-co-BA) Core-shell Composite Emulsion Film

采用饥饿态加料的两阶段乳液聚合法,制备了由苯乙烯-丙烯酸丁酯无规共聚物和甲基丙烯酸甲酯-丙烯酸丁酯无规共聚物组成的核壳型复合乳液,测定了该复合乳液成膜过程中水的蒸发速率,根据干燥速率的变化将苯丙核壳型乳液的成膜过程分为3个阶段。此外,考察了不同温度、压力、固含量、乳化剂用量、AAc用量、壳层玻璃化转变温度等因素对乳液的失水量、干燥速率的影响。结果表明,增加温度、降低压力可显著增加乳液的失水量和干燥速率;而改变其它因素仅仅影响失水量但不影响恒速干燥速率。

Composite latex of P（ St - co - BA）/P（ MMA - co - BA） was synthesized by two - step emulsion polymerization under starved conditions. The drying rate of the composite emulsion was investigated. The results demonstrated that the film formation process of styrene - acrylic emulsion could be divided into three steps based on the change of drying rate. Furthermore, effects of temperature, pressure, solid content, surfactant AAc content and Tg of shell et. al. on drying rate were also examined. It was found that the drying rate of latex could be accelerated with the increase of temperature and decrease of environmental pressure. Changing other factors only influenced the water loss but constant drying rate.