化学结构对聚合物侧链末端甲基在膜表面有序性排列的影响
发布时间：2019-02-20 07:49
【摘要】：聚合物薄膜的表面性质在涂层、密封以及生物相容性材料等领域起着至关重要的作用。材料的表面性质是由其表面最外几层分子结构所决定,包括最外层基团的排列。甲基是聚合物中普遍存在的基团,且表面能较低。在成膜过程中,往往在表面有较强的富集能力。表面甲基的排列结构会影响蛋白质吸附、血小板粘附以及血栓形成等相关性质。所以研究聚合物中甲基在薄膜表面的有序化排列过程及其影响因素,对薄膜表面结构的设计和调控有重要的指导意义。本论文以和频振动光谱(SFG)和界面红外反射吸收光谱(PM-IRRAS)为主要研究手段,研究了侧链长度、与主链连接的间隔基团及α-甲基对聚合物单分子膜、Langmuir-Blodgett膜和浇铸膜表面侧链末端甲基有序化过程的影响。得到以下结论:(1)对于聚丙烯酸甲酯(PMA)、聚丙烯酸乙酯(PEA)和聚丙烯酸丁酯(PBA),烷基侧链越长,酯基侧链末端甲基在其单分子膜、LB膜以及浇铸膜表面的富集能力越强,排列有序度增加越快。原因是由于PBA的烷基侧链较长,酯基的占比较少,其极性作用相对较弱。从而使得丁酯基侧链有较强的运动能力,丁酯基侧链末端甲基更容易往表面富集,排列有序度快速增大。对于聚甲基丙烯酸甲酯(PMMA)、聚甲基丙烯酸乙酯(PEMA)和聚甲基丙烯酸丁酯(PBMA),烷基侧链越短,酯基侧链末端甲基在单分子膜、LB膜以及浇铸膜表面的富集能力越强,排列有序度增加越快。原因是因为PBMA的丁酯基侧链体积相对较大,α-甲基的位阻效应对丁酯基侧链的限制更加明显,严重阻碍了丁酯基侧链的有序排列。从而导致PBMA的丁酯基侧链末端甲基不容易往薄膜表面富集。(2)研究了与主链连接的间隔基团对侧甲基在单分子膜、LB膜和浇铸膜表面富集行为及其有序性排列的影响。以聚乙烯基甲基酮(PVMK)、聚乙烯基甲醚(PVME)、聚丙烯酸甲酯(PMA)和聚醋酸乙烯酯(PVAc)为研究体系。发现羰基和醚基连接的侧甲基在其单分子膜、LB膜和浇铸膜表面的富集能力较强,排列有序度增加较快。酯基和乙酰基连接的侧甲基在单分子膜、LB膜和浇铸膜表面的富集能力较弱,排列有序度增加较慢。原因可能是因为相比于羰基和醚基,酯基和乙酰基的极性更强,它们连接的侧甲基柔性小。因而酯基和乙酰基连接的侧甲基运动能力较弱,不太容易往表面富集。
[Abstract]:The surface properties of polymer films play an important role in coating, sealing and biocompatibility materials. The surface properties of the material are determined by its outermost molecular structure, including the arrangement of the outermost groups. Methyl is a common group in polymers, and the surface energy is low. In the process of film formation, there is a strong enrichment ability on the surface. The structure of surface methylation affects the properties of protein adsorption, platelet adhesion and thrombosis. Therefore, it is of great significance to study the ordered arrangement of methyl in the polymer and its influencing factors for the design and regulation of the surface structure of the film. In this thesis, the sum frequency vibrational spectrum (SFG) and the interface infrared reflectance absorption spectroscopy (PM-IRRAS) were used to study the length of side chain, the spacer groups connected to the main chain and the 伪 -methyl-pair polymer monolayers. Effects of side chain end Methyl ordering on the Surface of Langmuir-Blodgett Film and cast Film. The following conclusions are obtained: (1) the longer the alkyl side chain of polymethyl acrylate (PMA),) ethyl acrylate (PEA) and polybutyl acrylate (PBA), the end methyl group of the ester side chain is in its monolayer membrane. The stronger the enrichment ability of LB film and casting film is, the faster the order of arrangement increases. The reason is that the alkyl side chain of PBA is longer, the proportion of ester group is less, and the polarity of PBA is relatively weak. Therefore, the butylated side chain has a strong mobility, and the methyl group at the end of the butyl side chain is easier to enrich to the surface, and the ordering degree increases rapidly. The shorter the alkyl chain of poly (methyl methacrylate) (PMMA), polyethyl methacrylate (PEMA) and polybutyl methacrylate (PBMA), the stronger the enrichment ability of methyl ester on the surface of monolayer, LB film and cast film. The faster the order of arrangement increases. The reason is that the volume of butyl side chain of PBMA is relatively large, and the steric resistance effect of 伪 -methyl has more obvious limitation on butyl side chain, which seriously hinders the ordered arrangement of butyl side chain. As a result, the butylated side chain end methyl of PBMA is not easy to enrich on the surface of the film. (2) the effect of the opposite side methyl groups connected with the main chain on the surface enrichment behavior and ordered arrangement of monolayer, LB film and cast film are studied. Polyethylene methyl ketone (PVMK),) polyethylene methyl ether (PVME),) polymethyl acrylate (PMA) and poly (vinyl acetate) (PVAc) were used as study systems. It was found that the side methyl group connected with carbonyl group and ether group had strong enrichment ability on the surface of monolayer, LB film and casting film, and the order degree of arrangement increased rapidly. On the surface of monolayers, LB films and cast films, the side methyl groups connected with ester and acetyl groups have weak enrichment ability, and the order degree of arrangement increases more slowly. The reason may be that the polarity of ester group and acetyl group is stronger than that of carbonyl group and ether group. As a result, the side methyl group connected with ester group and acetyl group has weak mobility and is not easy to enrich on the surface.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O631;TB383.2
本文编号：2426967
[Abstract]:The surface properties of polymer films play an important role in coating, sealing and biocompatibility materials. The surface properties of the material are determined by its outermost molecular structure, including the arrangement of the outermost groups. Methyl is a common group in polymers, and the surface energy is low. In the process of film formation, there is a strong enrichment ability on the surface. The structure of surface methylation affects the properties of protein adsorption, platelet adhesion and thrombosis. Therefore, it is of great significance to study the ordered arrangement of methyl in the polymer and its influencing factors for the design and regulation of the surface structure of the film. In this thesis, the sum frequency vibrational spectrum (SFG) and the interface infrared reflectance absorption spectroscopy (PM-IRRAS) were used to study the length of side chain, the spacer groups connected to the main chain and the 伪 -methyl-pair polymer monolayers. Effects of side chain end Methyl ordering on the Surface of Langmuir-Blodgett Film and cast Film. The following conclusions are obtained: (1) the longer the alkyl side chain of polymethyl acrylate (PMA),) ethyl acrylate (PEA) and polybutyl acrylate (PBA), the end methyl group of the ester side chain is in its monolayer membrane. The stronger the enrichment ability of LB film and casting film is, the faster the order of arrangement increases. The reason is that the alkyl side chain of PBA is longer, the proportion of ester group is less, and the polarity of PBA is relatively weak. Therefore, the butylated side chain has a strong mobility, and the methyl group at the end of the butyl side chain is easier to enrich to the surface, and the ordering degree increases rapidly. The shorter the alkyl chain of poly (methyl methacrylate) (PMMA), polyethyl methacrylate (PEMA) and polybutyl methacrylate (PBMA), the stronger the enrichment ability of methyl ester on the surface of monolayer, LB film and cast film. The faster the order of arrangement increases. The reason is that the volume of butyl side chain of PBMA is relatively large, and the steric resistance effect of 伪 -methyl has more obvious limitation on butyl side chain, which seriously hinders the ordered arrangement of butyl side chain. As a result, the butylated side chain end methyl of PBMA is not easy to enrich on the surface of the film. (2) the effect of the opposite side methyl groups connected with the main chain on the surface enrichment behavior and ordered arrangement of monolayer, LB film and cast film are studied. Polyethylene methyl ketone (PVMK),) polyethylene methyl ether (PVME),) polymethyl acrylate (PMA) and poly (vinyl acetate) (PVAc) were used as study systems. It was found that the side methyl group connected with carbonyl group and ether group had strong enrichment ability on the surface of monolayer, LB film and casting film, and the order degree of arrangement increased rapidly. On the surface of monolayers, LB films and cast films, the side methyl groups connected with ester and acetyl groups have weak enrichment ability, and the order degree of arrangement increases more slowly. The reason may be that the polarity of ester group and acetyl group is stronger than that of carbonyl group and ether group. As a result, the side methyl group connected with ester group and acetyl group has weak mobility and is not easy to enrich on the surface.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O631;TB383.2
【相似文献】
相关期刊论文 前2条
1 戈明亮;贾德民;;偏氟乙烯-六氟丙烯共聚物溶剂浇铸膜的非等温结晶动力学行为[J];合成材料老化与应用;2008年04期
2 ;[J];;年期
相关会议论文 前1条
1 王强;赵冰;张希;李宏斌;沈家骢;;傅里叶变换红外掠角反射—吸收光谱对倒浮萍聚合物ES-1浇铸膜有序—无序相变的研究[A];全国第10届分子光谱学术报告会论文集[C];1998年
相关博士学位论文 前1条
1 卜伟锋;通向超分子软材料：表面活性剂包埋的杂多酸复合物[D];吉林大学;2004年
相关硕士学位论文 前1条
1 陈相;化学结构对聚合物侧链末端甲基在膜表面有序性排列的影响[D];浙江理工大学;2016年
，本文编号：2426967
本文链接：https://www.wllwen.com/kejilunwen/huaxue/2426967.html
教材专著
