| Polymer emulsion with hollow latex particles, which is film-formable under room temperature and can be cross-linked under high temperature, was prepared by core-shell emulsion polymerization under low emulsifier condition. Firstly, seed particles were manufactured by using methyl methacrylate (MMA), methacrylic acid (MAA) and butyl acrylate as co-monomers and on the basis of the prepared emulsion, core particles with carboxylic groups were synthesized by using MMA, MAA and divinyl benzene(DVB) as co-monomers. And then, styrene (St), MAA, BA and DVB were polymerized to form a cross-linked intermediated layer over the core particles. The copolymer of BA and glycidyl methacrylate (GMA) was polymerized over the particles subsequently. Finally, the hollow latex particles with functional groups were obtained by alkalization treatment to the core-shell latex particles. In addition, hydroxyethyl methacrylate (HEMA) and BA copolymer emulsions were prepared to be blended with the hollow emulsions. The composite emulsion is film-formable under room temperature and can be cross-linked under high temperature.The technology for preparing the hollow latex particles and the effects on the particle morphologies and the film properties were studied in detail. The optimal conditions for preparing the hollow latex particles were obtained. In the polymerization, SDBS can be used as emulsifier. Its dosages can be 0.8mass% and 0.4mass% in the seed/core stage and the shell stage, respectively. In the preparation of the intermediated layer, the dosage of the cross-linker DVB can be 4.0mass% and MAA 10.0mass%. In the shell stage, starved feeding strategy for monomers can be adopted and the monomer feeding rate can be 8g/h in the present scale. The weight ratio of core polymers to shell polymers can be 1:5 and the weight ratio of soft monomers to hard monomers 2:1. The hollow structure of the prepared particles is clear and the properties of the polymer film are excellent. |
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