The effects of ionic emulsifier, sodium dodecylbenzene sulfate (SDBS), on the formation of the multihollow structures in sub-micron sized polymer particles produced by alkali/acid posttreatment were investigated. The ...The effects of ionic emulsifier, sodium dodecylbenzene sulfate (SDBS), on the formation of the multihollow structures in sub-micron sized polymer particles produced by alkali/acid posttreatment were investigated. The original latex particles with narrow size distribution were synthesized by a new sequence emulsifier-free/emulsifier emulsion copolymerization of styrene (St) and methacrylic acid (MAA). Results indicated that the pore size decreased and the pore number increased with the increase of SDBS amount, and the morphology of the posttreated latex particles was also significantly influenced by the introducing time of SDBS in the preparation of the original latex particles, and a suitable introducing time was 3 h of polymerization. (c) 2007 Cheng You Kan. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methac...Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methacrylic acid) were then carried out in the absence of surfactant. Final latex was treated by a two step treatment under alkaline and acidic conditions, thus, the particles with hollow structure were obtained. We discussed the effects of pH value, temperature and time in alkali and acid treatment processes on hollow structure within the polymer latex particles and amount of carboxylic group on particle surface. The results show that the hollow polymer latex particles with the largest hollow size can be obtained under a certain condition (pH12.5, 90°C, 3 h in alkali treatment stage and pH2.5, 85°C, 3 h in acid treatment stage).展开更多
Micron-sized nonspherical polymer particles having different morphologies were synthesized by seeded soap-free emulsion polymerization of styrene （St） and ethyleneglycol dimethacrylate （EGDMA, used as a crosslinker...Micron-sized nonspherical polymer particles having different morphologies were synthesized by seeded soap-free emulsion polymerization of styrene （St） and ethyleneglycol dimethacrylate （EGDMA, used as a crosslinker） on spherical, linear polystyrene （PS） seed particles. The morphology of the resulting PS/poly（St-co-EGDMA） particles was dependent on the crosslinker concentration and polymerization temperature.展开更多
Crosslinked x-P（St-MAA） seed latex was first prepared via soap-free emulsion copolymerization of styrene （St） and methyl methacrylic acid （MAA） with divinyl benzene as crosslinker and ammonium persulfate as init...Crosslinked x-P（St-MAA） seed latex was first prepared via soap-free emulsion copolymerization of styrene （St） and methyl methacrylic acid （MAA） with divinyl benzene as crosslinker and ammonium persulfate as initiator, and x-P（St-MAA）/x-P（St-NaSS） core/shell latex particles were then synthesized through a novel seeded emulsion copolymerization of St and sodium styrene sulphonate （NaSS） in the presence of water-soluble crosslinker N,N＇-methylene bisacrylamide （BAA） using oil-soluble 2,2-azobis isobutyronitrile as initiator. TEM observation indicated that narrow dispersed core/shell latex particles were obtained, and element analysis showed that NaSS unit content in the whole particle and in the shell reached 22.8 wt% and 51.2 wt%, respectively.展开更多
文摘The effects of ionic emulsifier, sodium dodecylbenzene sulfate (SDBS), on the formation of the multihollow structures in sub-micron sized polymer particles produced by alkali/acid posttreatment were investigated. The original latex particles with narrow size distribution were synthesized by a new sequence emulsifier-free/emulsifier emulsion copolymerization of styrene (St) and methacrylic acid (MAA). Results indicated that the pore size decreased and the pore number increased with the increase of SDBS amount, and the morphology of the posttreated latex particles was also significantly influenced by the introducing time of SDBS in the preparation of the original latex particles, and a suitable introducing time was 3 h of polymerization. (c) 2007 Cheng You Kan. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methacrylic acid) were then carried out in the absence of surfactant. Final latex was treated by a two step treatment under alkaline and acidic conditions, thus, the particles with hollow structure were obtained. We discussed the effects of pH value, temperature and time in alkali and acid treatment processes on hollow structure within the polymer latex particles and amount of carboxylic group on particle surface. The results show that the hollow polymer latex particles with the largest hollow size can be obtained under a certain condition (pH12.5, 90°C, 3 h in alkali treatment stage and pH2.5, 85°C, 3 h in acid treatment stage).
基金partially supported by the National Natural Science Foundation of China(No.50943028)Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘Micron-sized nonspherical polymer particles having different morphologies were synthesized by seeded soap-free emulsion polymerization of styrene （St） and ethyleneglycol dimethacrylate （EGDMA, used as a crosslinker） on spherical, linear polystyrene （PS） seed particles. The morphology of the resulting PS/poly（St-co-EGDMA） particles was dependent on the crosslinker concentration and polymerization temperature.
基金financially supported by the National Basic Research Program of China(No.2014CB932202)
文摘Crosslinked x-P（St-MAA） seed latex was first prepared via soap-free emulsion copolymerization of styrene （St） and methyl methacrylic acid （MAA） with divinyl benzene as crosslinker and ammonium persulfate as initiator, and x-P（St-MAA）/x-P（St-NaSS） core/shell latex particles were then synthesized through a novel seeded emulsion copolymerization of St and sodium styrene sulphonate （NaSS） in the presence of water-soluble crosslinker N,N＇-methylene bisacrylamide （BAA） using oil-soluble 2,2-azobis isobutyronitrile as initiator. TEM observation indicated that narrow dispersed core/shell latex particles were obtained, and element analysis showed that NaSS unit content in the whole particle and in the shell reached 22.8 wt% and 51.2 wt%, respectively.
