【摘要】： 目前ATRP法制備含氟丙烯酸酯嵌段聚合物多采用單一丙烯酸酯單體和含氟丙烯酸酯類單體聚合而成,制備出的涂膜附著力不高,硬度等綜合性能不優(yōu)。本文針對上述問題,首先采用ATRP法合成可交聯(lián)型大分子引發(fā)劑P(MMA-HEMA-BMA)-Br,再引發(fā)含氟丙烯酸酯類單體(FMA)聚合生成嵌段共聚物,并選用選擇性溶劑,使聚合物在選擇性溶劑中形成膠束,成膜時構(gòu)筑粗糙結(jié)構(gòu),從而形成較好的疏水表面。 研究中,運用Materials Studio4.4(MS)軟件進行分子模擬,首先選用DPD模塊對溶液中的膠束進行介觀模擬,考察了溶劑、鏈長、聚合物在有機物中的濃度對膠束形態(tài)和粒徑尺寸的影響。結(jié)果發(fā)現(xiàn):嵌段共聚物PMMA-b-PFMA在選擇性溶劑THF、F113中容易形成核殼型膠束。隨著濃度的增加,體系由球形膠束變?yōu)槟z束簇,當濃度繼續(xù)增大,不能形成規(guī)整的膠束結(jié)構(gòu)。鏈段越長形成的膠束粒徑越大。其次,通過分子動力學模擬(MD),可知含氟基團有表面遷移的現(xiàn)象。嵌段共聚物中的含氟基團比無規(guī)共聚物中的更容易向涂膜表面遷移。成膜溫度為353K(80℃)時,表面遷移的氟含量最高。本模擬對含氟嵌段共聚物制備疏水性涂膜的研究工作具有積極的指導作用。 為提高附著力,引入功能單體甲基丙烯酸羥乙酯(HEMA),與甲基丙烯酸甲酯(MMA)、甲基丙烯酸丁酯(BMA)共聚,以溴代丙酸乙酯(EPN-Br)為引發(fā)劑,CuCl為催化劑,2,2’-聯(lián)吡啶(bpy)為配位劑,ATRP法合成可交聯(lián)型大分子引發(fā)劑P(MMA-HEMA-BMA)-Br。用GPC、FTIR、1HNMR進行表征和分析�？疾炝藛误w種類、反應溫度、催化體系、溶劑含量對產(chǎn)物轉(zhuǎn)化率、分子量及分子量分布、涂膜性能的影響。結(jié)果表明:當單體為MMA/HEMA/BMA,聚合反應溫度為110℃,反應時間為8h,催化體系為(EPN-Br/CuCl/bpy),溶劑含量為20%時,產(chǎn)物轉(zhuǎn)化率最高為73.4%,分子量可達20000,分子量分布為1.49,樹脂涂膜的附著力達到1級,硬度為H。 在上述制備的大分子引發(fā)劑P(MMA-HEMA-BMA)-Br的基礎上,引入含氟丙烯酸酯類單體,ATRP法合成含氟嵌段共聚物P(MMA-HEMA-BMA)-b-PFMA,用GPC、FTIR、1HNMR進行表征和分析�？疾炝朔磻獪囟�,反應時間,單體與引發(fā)劑的比例,反應順序?qū)D(zhuǎn)化率和分子量及分布的影響。結(jié)果表明:當聚合反應溫度為130℃,反應時間為24h,[FMA]:[P(MMA-HEMA-BMA)-Br]=50:1時,反應順序為先合成丙烯酸酯類大分子引發(fā)劑,再引發(fā)FMA,含氟鏈段較長,分子量分布較窄(1.30)。 嵌段聚合物在THF、DMF、F113、氫氟醚等選擇性溶劑中形成核殼膠束,成膜時,納米膠束會聚集形成微納米結(jié)構(gòu)的粗糙表面,同時由于含氟基團的遷移,表面能降低,從而制備出疏水涂膜。在THF、DMF、F113、氫氟醚中形成的接觸角依次增大,含氟鏈段越長,涂膜接觸角越大。當成膜溫度為353K(80℃)時,接觸角最大為135.2°,涂膜附著力為1級,硬度為HB,表現(xiàn)出良好的綜合性能。
[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，

本文編號：2179216