Study On The Synthesis And Performance Of Polymer With Comb Sturcture From Vinyl Acetate

Comb polymers are widely used due to its special molecular structure, more typical is the use of Polycarboxylate Superplasticizer(PCE) in the field of building materials. Comb structure of PCE agent to make the molecules with excellent space steric effect. So that it has excellent water reducing performance. Used in the synthesis of PCE polyether material is ethylene oxide or propylene oxide. However, ethylene oxide and propylene oxide are flammabled, and its storage and transportation are difficulties. At the same time, the synthesis of macromonomer in harsh conditions, and the production equipment in high pressure and sealing requirements. And the source of ethylene oxide and propylene oxide are single. The promotion and development of water reducer has brought great limitation and risk. The whole poly carboxylic acid water reducer agent industry supply and demand relationship is particularly sensitive and fragile. This needs a novel type of water reducer to achieve the structural revolution and innovation as well as the convenience and normalization of synthesis process. By applying the structural design theory of polymer to the field of concrete admixture, we use vinyl acetate as the main raw material, by the methods of chain transfer polymerization, synthesizing main chain and then grafted side chain, and finally a novel Comb polymer with side chain of polyvinyl alcohol structure was innovatively synthesized. It is applied to the field of water reducing agent, which breaks through the bottleneck of molecular design of water reducing agent. It can solve the problem indeed and achieved the diversification of raw materials, the conventional of synthesis method, and greatly reduced the risk of production. A novel comb shaped polymer was synthesized by designing a series of different single structural variables. The dispersion and water reducing performance and its influence law were studied. It is found that the optimal synthesis parameter of the new comb polymer is: The best relative molecular weight of butyl acrylate is 8786g/mol;When grafted side reaction, ninitiator=nvinyl acetate×3%, mcomponent solvent:mvinyl acetate=4:1, nvinyl acetate:nbutyl acrylate=20:1; In the alcoholysis reaction process, The best reaction temperature is 45?, m Na OH/mester=2.5%. The change of functional groups in the synthesis process is in conformity with the experimental design by infrared spectrum, The structure of the synthetic polymercomb like molecules was verified by the results of TG?1H NMR?13C NMR and DEPT. By GPC measured the comb shaped polymer quality was changed, and its purity was 92%. The feasibility of the purification method used in the experiment is proved. The synthesis method is simple and common, manifesting as energy conservation and high efficiency. A novel comb structure was synthesized by a new material and applied to the field of water reducing agent, it will greatly promote the development of water reducing agent industry. The innovative research results will enrich the theory of molecular structure design, and provide important guidance to fundamental research of water reducer.