【作者】 赵明；

【导师】 王子明； 蒋荃；

【作者基本信息】 北京工业大学 ， 材料工程（专业学位）， 2016， 硕士

【摘要】 梳形结构聚合物由于其特殊的分子结构而被广泛应用于各个行业,比较典型的是建筑材料领域中使用的聚羧酸减水剂(PCE),其梳形结构使分子具有较大的空间位阻作用,从而表现出优良的减水性能。然而,合成PCE所用的聚醚大单体的主要原料—环氧乙烷/丙烷属于易燃易爆化学品,仓储及运输困难;合成聚羧酸减水剂用聚醚大单体的条件苛刻,生产设备要求很高,生产操作危险系数很大;而且环氧乙烷/丙烷来源单一,长期受控于中石化等几家企业,给聚羧酸系减水剂产品的生产和应用带来很大的限制和风险,整个聚羧酸减水剂行业的供求关系非常敏感和脆弱,迫切需要寻求其它种类的原料制备出新品种的减水剂,实现减水剂生产的创新化发展,及合成工艺的便捷化。本研究将高分子的结构设计原理应用于混凝土外加剂领域,探索了链转移自由基聚合的合成途径,开创性地以乙酸乙烯酯为主要原料,通过先合成主链再接枝侧链的方法,合成一种以聚乙烯醇为侧链结构的新型梳形聚合物,并将其应用到减水剂领域,实现了原料来源的多样化,合成方法的常规化。通过优选不同的单一结构变量合成出新型的梳形聚合物,并对其分散减水性能及其影响规律进行了测试,发现新型梳形聚合物制备的最佳合成参数是:主链聚丙烯酸丁酯最佳相对分子量为8786g/mol;侧链接枝反应时,n引发剂=n乙酸乙烯酯×2.0%,m混合溶剂:m乙酸乙烯酯=4:1,n乙酸乙烯酯:n丙烯酸丁酯=20:1;在醇解反应过程中,最佳反应温度为45℃,mNaOH/m酯=2.5%。通过红外光谱测得合成过程中官能团的变化与实验设计路线相符,通过热重曲线、核磁氢谱、13C NMR和DEPT谱结果验证了合成聚合物梳形分子的结构与所设计的聚丙烯酸-g-聚乙烯醇结构相符,证明得到了设计的梳形分子结构聚合物。通过GPC测得制备的梳形聚合物分子量,且其纯度达到92%,证明了实验中所采用提纯方法的可行性。实验所用合成方式常见、步骤简单、节能高效,以一种新的原料合成新型的梳形结构聚合物,并将其应用到减水剂领域,增加了减水剂的种类,开拓了梳形结构聚合物的合成新技术,对混凝土减水剂领域的基础研究和产业的发展具有重要作用。更多还原

【Abstract】 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.更多还原