ATRP法制备可交联型含氟嵌段共聚物及其在疏水涂膜中的应用
发布时间：2018-08-12 13:37
【摘要】： 目前ATRP法制备含氟丙烯酸酯嵌段聚合物多采用单一丙烯酸酯单体和含氟丙烯酸酯类单体聚合而成,制备出的涂膜附着力不高,硬度等综合性能不优。本文针对上述问题,首先采用ATRP法合成可交联型大分子引发剂P(MMA-HEMA-BMA)-Br,再引发含氟丙烯酸酯类单体(FMA)聚合生成嵌段共聚物,并选用选择性溶剂,使聚合物在选择性溶剂中形成胶束,成膜时构筑粗糙结构,从而形成较好的疏水表面。 研究中,运用Materials Studio4.4(MS)软件进行分子模拟,首先选用DPD模块对溶液中的胶束进行介观模拟,考察了溶剂、链长、聚合物在有机物中的浓度对胶束形态和粒径尺寸的影响。结果发现:嵌段共聚物PMMA-b-PFMA在选择性溶剂THF、F113中容易形成核壳型胶束。随着浓度的增加,体系由球形胶束变为胶束簇,当浓度继续增大,不能形成规整的胶束结构。链段越长形成的胶束粒径越大。其次,通过分子动力学模拟(MD),可知含氟基团有表面迁移的现象。嵌段共聚物中的含氟基团比无规共聚物中的更容易向涂膜表面迁移。成膜温度为353K(80℃)时,表面迁移的氟含量最高。本模拟对含氟嵌段共聚物制备疏水性涂膜的研究工作具有积极的指导作用。 为提高附着力,引入功能单体甲基丙烯酸羟乙酯(HEMA),与甲基丙烯酸甲酯(MMA)、甲基丙烯酸丁酯(BMA)共聚,以溴代丙酸乙酯(EPN-Br)为引发剂,CuCl为催化剂,2,2’-联吡啶(bpy)为配位剂,ATRP法合成可交联型大分子引发剂P(MMA-HEMA-BMA)-Br。用GPC、FTIR、1HNMR进行表征和分析。考察了单体种类、反应温度、催化体系、溶剂含量对产物转化率、分子量及分子量分布、涂膜性能的影响。结果表明:当单体为MMA/HEMA/BMA,聚合反应温度为110℃,反应时间为8h,催化体系为(EPN-Br/CuCl/bpy),溶剂含量为20%时,产物转化率最高为73.4%,分子量可达20000,分子量分布为1.49,树脂涂膜的附着力达到1级,硬度为H。 在上述制备的大分子引发剂P(MMA-HEMA-BMA)-Br的基础上,引入含氟丙烯酸酯类单体,ATRP法合成含氟嵌段共聚物P(MMA-HEMA-BMA)-b-PFMA,用GPC、FTIR、1HNMR进行表征和分析。考察了反应温度,反应时间,单体与引发剂的比例,反应顺序对转化率和分子量及分布的影响。结果表明:当聚合反应温度为130℃,反应时间为24h,[FMA]:[P(MMA-HEMA-BMA)-Br]=50:1时,反应顺序为先合成丙烯酸酯类大分子引发剂,再引发FMA,含氟链段较长,分子量分布较窄(1.30)。 嵌段聚合物在THF、DMF、F113、氢氟醚等选择性溶剂中形成核壳胶束,成膜时,纳米胶束会聚集形成微纳米结构的粗糙表面,同时由于含氟基团的迁移,表面能降低,从而制备出疏水涂膜。在THF、DMF、F113、氢氟醚中形成的接触角依次增大,含氟链段越长,涂膜接触角越大。当成膜温度为353K(80℃)时,接触角最大为135.2°,涂膜附着力为1级,硬度为HB,表现出良好的综合性能。
[Abstract]:At present, fluorinated acrylate block polymers prepared by ATRP method are mostly polymerized by single acrylate monomer and fluorinated acrylate monomer. The coating film has low adhesion and poor hardness. In order to solve the above problems, the cross-linked macromolecular initiator P (MMA-HEMA-BMA) -Brwas synthesized by ATRP method, and then the block copolymer was synthesized by (FMA) polymerization of fluorinated acrylate monomers. The selective solvent was used to form micelles in the selective solvents. A rough structure is formed during film formation, thus forming a better hydrophobic surface. In the study, Materials Studio4.4 (MS) software was used to simulate the micelles in the solution. The effects of solvent, chain length and polymer concentration on the morphology and particle size of the micelles were investigated by using the DPD module. The results show that the block copolymer PMMA-b-PFMA is easy to form core-shell micelles in the selective solvent THF F113. With the increase of concentration, the system changed from spherical micelle to micellar cluster, and when the concentration increased, it could not form a regular micelle structure. The longer the chain segment, the larger the particle size of the micelle formed. Secondly, the surface migration of fluorine groups was observed by molecular dynamics simulation (MD),). Fluorine groups in block copolymers are easier to migrate to the coating surface than those in random copolymers. When the film forming temperature is 353K (80 鈩，
本文编号：2179216
[Abstract]:At present, fluorinated acrylate block polymers prepared by ATRP method are mostly polymerized by single acrylate monomer and fluorinated acrylate monomer. The coating film has low adhesion and poor hardness. In order to solve the above problems, the cross-linked macromolecular initiator P (MMA-HEMA-BMA) -Brwas synthesized by ATRP method, and then the block copolymer was synthesized by (FMA) polymerization of fluorinated acrylate monomers. The selective solvent was used to form micelles in the selective solvents. A rough structure is formed during film formation, thus forming a better hydrophobic surface. In the study, Materials Studio4.4 (MS) software was used to simulate the micelles in the solution. The effects of solvent, chain length and polymer concentration on the morphology and particle size of the micelles were investigated by using the DPD module. The results show that the block copolymer PMMA-b-PFMA is easy to form core-shell micelles in the selective solvent THF F113. With the increase of concentration, the system changed from spherical micelle to micellar cluster, and when the concentration increased, it could not form a regular micelle structure. The longer the chain segment, the larger the particle size of the micelle formed. Secondly, the surface migration of fluorine groups was observed by molecular dynamics simulation (MD),). Fluorine groups in block copolymers are easier to migrate to the coating surface than those in random copolymers. When the film forming temperature is 353K (80 鈩，
本文编号：2179216
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