Study On Gtafating Modification Chlorinated Rubber

Chlorinated rubber coating is one of widely used heavy-duty anti-corrosion coatings.Long-term practical applications have explored obvious defects of the chlorinated rubber coating:the poor compatibility of chlorinated rubber with coating auxiliaries caused relatively low solid contents of the prepared coatings(about 35%),as while as high VOC values.As the country paying more and more attention to environment problem,stricter rules has been drawn for the VOC content of coatings in the latest environmental regulations made in the early 2015’s.Coatings with low solid contents face the crisis of being obsoleted.To solve the problem of low solid content chlorinated rubber coating has become an urgent task to extend the productivity of chlorinated rubber coating,thus has great practical significance.Based on free radical reaction mechanism,this thesis systematically studied the graft modification of chlorinated rubber with the solution grafting method,by using chloroform as solvent,azodiisobutyronitrile as initiator,and vinyl acetate(VAc)and acrylic acid(AA)as grafting monomers.The graft modified chlorinated rubber product has significantly higher solubility with the coating additives.The main research contents and results are as follows:(1)This thesis explored the grafting reaction rules for preparation of CR-g-VAc and CR-g-AA.IR characterization indicates that both vinyl acetate and acrylic acid can grafted to the chlorinated rubber polymer chain.The optimum reaction conditions for preparation of vinyl acetate and acrylic acid grafted chlorinated rubbers were obtained;grafting ratios of CR-g-VAc and CR-g-AA under the optimum conditions are 12.18%and 6.32%,respectively;(2)This thesis established an accurate measurement method for analysis of the grafting ratios of CR-g-VAc and CR-g-AA;(3)Thermal stability study showed that thermal stability of grafted chlorinated rubber has little change compared to the original one;(4)The compatibility of grafted products with coating auxiliaries was studied.The compatibility of CR-g-VAc and CR-g-AA with titanium dioxide and phenolic resin was determined,respectively.Results showed that the compatibility of the two grafted chlorinated rubber with the phenolic resin was almost unchanged compared with the un-grafted one.The compatibility of the two grafted products with the titanium dioxide were significantly increased for 11.66%and 6.66%,respectively.And the compatibility of the two grafted products with the mixture of phenolic resin and titanium dioxide were also significantly increased for 8.51%and 4.59%,respectively.