| With the increasing emphasis on environment and performance of product, less polluting and higher performance will become the developing trend of chemical product. Chlorinated rubber had applied in coating area for many years, its production process requires carbon tetrachloride as solvent, and the solvent will also left in the product. The solubility and compatibility of chlorinated rubber and the synthesis of chlorinated rubber in aqueous medium are not satisfactory. Therefore, developing a new chlorinated polymer to replace the chlorinated rubber is significant. Vinyl chloride-isobutyl vinyl ether copolymer is synthesized with VC and VIBE by suspension polymerization in aqueous medium. Compare with chlorinated rubber, the production process of VC-VIBE does not harm to environment, the weather resistance and liquid medium resistance properties of VC-VIBE are better than chlorinated rubber's. So VC-VIBE will instead of chlorinated rubber and become a popular product in coating and ink area. In order to improve the properties of VC-VIBE, the surface of nano-SiO2 particles was modified and nano-SiO2/VC-VIBE composite was prepared by in situ polymerization. All the research of contents and results are as follows:In the first section of dissertation, synthesis, applications, modification methods and developing trend of VC-VIBE were reviewed. The preparation methods of nano-SiO2/polymer composite by in situ polymerization were introduced.In the second section of dissertation, VC-VIBE copolymer was prepared by suspension polymerization in aqueous medium in the presence of VC, VIBE, initiator (LPO) and dispersant (hydroxypropyl cellulose). After the reaction, product was white particles by washing and drying. The microstructure of Laroflex MP45 and product was characterized by FT-IR,1H-NMR, DSC, TGA and elemental analysis respectively. The results show that the microstructure of MP45 and product was almost identical. The particle size of product was larger than MP45, and the DSC test s show that drying temperature had significant influence on the properties of product. The temperature over 50℃will cause product go yellow and caked.In the third section of dissertation, nano-SiO2 was modified with KH570, from which the core-shell nano-SiO2/VC-VIBE composite particles were prepared by suspension polymerization in aqueous medium. The relationship of the pH, reaction time, amount of KH570 and grafted fraction of KH570 on nano-Si02 were discussed. The relationship of nano-SiO2 adding method, morphology of nanocomposite particles and properties of product were also discussed in this section. The result show that the surface of nano-SiO2 modified well when pH=8～9, ultrasonic dispersion for 1.5h, stirring for 2h, adding 80%(wt) KH570. After drying, pre-disperse the modified nano-SiO2 in VIBE, and then start the polymerization. The core-shell nano-SiO2/VC-VIBE composite particles would prepared by this method.In the fourth section of the dissertation, an anticorrosion coating with high performance was prepared based on VC-VIBE as binder. The influence of nano-SiO2, varieties and particle size of pigment, P/B ratio and coating additives on the performance of the coatings were discussed. The corrosion resistance of coatings was investigated through corrosion tests in liquid resistance test. Results indicated that the nano-SiO2 can increase corrosive resistance; the P/B ratio had significant influence on the anticorrosive performance of the coatings. The anticorrosive performance of the coatings increased with increasing of P/B ratio, and then the anticorrosive performance of the coatings decreased with further increase of the P/B ratio. And the coating with P/B ratio of 2:1 had the best anticorrosive performance. |
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