摘要
Phase inversion emulsification technique is an effective physical method to prepare waterborne dispersions of polymeric resins. In this study, a multi\|hollow epoxy resin sphere was obtained by incomplete phase inversion emulsification. The dynamic morphological evolution of water droplets dispersed in bisphenol. A epoxy resin/emulsifier (a multi\|block copolymer) during phase inversion process was investigated with scanning electron microscopy. It is shown that small discrete water droplets are dispersed in the epoxy resin continuous phase at low water content. In this case, the dynamic coalescence among the small water droplets is ignored. With increasing water content, the dynamic coalescence becomes remarkable and larger water drops are formed by the coalescence among the small water droplets. The larger water drops are randomly distributed within the continuous phase. Meanwhile, some necklace like structures with varied length co\|exist with the small water droplets and larger water drops. Incomplete phase inversion is achieved through the coalescence among the larger water drops, and some small water droplets are entrapped therein. In this case, a kind of multi\|hollow sphere is obtained. While, in some local regions, all the nearest small water droplets coalesce simultaneously to be continuous phase to achieve complete phase inversion, and small discrete waterborne particles are obtained. The dynamic coalescence among the small water droplets dispersed in epoxy resin continuous phase could be analyzed in terms of the improved Smoluchowski equation.
Phase inversion emulsification technique is an effective physical method to prepare waterborne dispersions of polymeric resins. In this study, a multi\|hollow epoxy resin sphere was obtained by incomplete phase inversion emulsification. The dynamic morphological evolution of water droplets dispersed in bisphenol. A epoxy resin/emulsifier (a multi\|block copolymer) during phase inversion process was investigated with scanning electron microscopy. It is shown that small discrete water droplets are dispersed in the epoxy resin continuous phase at low water content. In this case, the dynamic coalescence among the small water droplets is ignored. With increasing water content, the dynamic coalescence becomes remarkable and larger water drops are formed by the coalescence among the small water droplets. The larger water drops are randomly distributed within the continuous phase. Meanwhile, some necklace like structures with varied length co\|exist with the small water droplets and larger water drops. Incomplete phase inversion is achieved through the coalescence among the larger water drops, and some small water droplets are entrapped therein. In this case, a kind of multi\|hollow sphere is obtained. While, in some local regions, all the nearest small water droplets coalesce simultaneously to be continuous phase to achieve complete phase inversion, and small discrete waterborne particles are obtained. The dynamic coalescence among the small water droplets dispersed in epoxy resin continuous phase could be analyzed in terms of the improved Smoluchowski equation.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2000年第4期514-517,共4页
Acta Polymerica Sinica
基金
国家自然科学基金!(基金号 2 97740 3 8)
国家科学技术部攀登计划预选项目
"高分子凝聚态物理基本问题研究"资助
关键词
分散相
水滴形态
不完全相反转乳化
高分子树脂
Incomplete phase inversion, Dispersed phase, Morphological evolution, Dynamic coalescence
