The Effect of Nano-SiO2 Colloid on Soap-free Emulsion Polymerization of Methyl Methacrylate and Hydroxyethyl Methacrylate |
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| Authors: | Cai-Li Yu Jian-Shu Kang Fa-Ai Zhang |
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| Institution: | 1. Key Laboratory of Nonferrous Materials and New Processing Technology, Ministry of Education;2. Department of Material and Chemical Engineering , Guilin University of Technology , Guilin, 541004, P. R. China |
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| Abstract: | Soap-free emulsion polymerization of methyl methacrylate (MMA) and hydroxyethyl methacrylate (HEMA) was carried out in the presence of colloidal nano-SiO2 particles. The effect of nano-SiO2 level on the monomer conversion, polymerization rate (Rp), and emulsion stability was investigated. The viscosity, particle size distribution of the emulsions, surface tension, and ionic conductivity of these systems were determined. Upon the introduction of the nano-SiO2 particles into this system, the Rp and monomer conversion increased and the average particle size of the P(MMA-HEMA) emulsion decreased in comparison to emulsions formed in the absence of nano-SiO2. However, the particle size distribution became broader to some degree. Scanning electron microscope observations demonstrated that the shape of these latex particles were uniformly spherical. The surface tension and ionic conductivity of the system increased significantly after polymerization, but the presence of nano-SiO2 resulted in an increase in surface tension and a decrease in ionic conductivity in comparison to the particle–free system. |
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| Keywords: | Soap-free emulsion polymerization nano-SiO2 colloid methyl methacrylate hydrophilic monomer polymerization rate particle size |
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