【作者】 杨番；

【导师】 张超灿；

【作者基本信息】 武汉理工大学 ， 材料学， 2008， 硕士

【摘要】 由于材料的组成和结构呈连续分布、材料的性质和功能沿厚度方向呈梯度变化,高分子梯度材料作为梯度功能材料的一个重要分支,在许多技术领域和日常生活领域都有着极大的应用前景。有机硅聚合物的表面能比丙烯酸酯类聚合物的表面能低,通过控制成膜条件,含硅丙烯酸酯类聚合物共混乳液在成膜时会发生自组织行为(如自分层),由此得到的有机硅高分子梯度膜的一侧表面具备有机硅的耐沾污、疏水、耐腐蚀和耐老化等优点,另一侧表面具备丙烯酸酯类聚合物优异的粘接性、成膜性、耐候性和装饰性。本论文首先用γ-甲基丙烯酰氧丙基三甲氧基硅烷(KH-570)和三甲基氯硅烷(CMS)发生取代反应合成高硅含量单体γ-甲基丙烯酰氧丙基三(三甲基硅氧基)硅烷(TRIS),不但解决了KH-570在乳液聚合过程中的水解问题,还引入了-Si(CH3)3基团,可以提高聚合物中的硅含量和憎水性。以甲基丙烯酸甲酯(MMA)和TRIS为原料,以十二烷基硫酸钠(SDS)和1-丙烯基-2-羟基烷基磺酸钠(COPS-1)为复配乳化剂,采用种子乳液聚合半连续滴加法,分别制备了有机硅均聚物(PTRIS)乳液、一系列不同配比的聚(TRIS-甲基丙烯酸甲酯)(P(TRIS-co-MMA))乳液和聚甲基丙烯酸甲酯(PMMA)乳液。测试结果表明,随着乳液中TRIS单体比例的增加,乳液的稳定性逐渐降低,乳胶粒的粒径增大而粒径分布变宽,并且共聚物出现宽泛的Tg平台；所合成的聚(TRIS-甲基丙烯酸甲酯)乳胶粒子具有三层核／壳结构的特殊形态。随着共聚物组分中TRIS含量的增加,各乳胶膜的表面能依次降低,疏水性能随之提高。由于乳液共混成膜时链段会发生自组织迁移,以一种聚(TRIS-甲基丙烯酸甲酯)核／壳乳液分别与三种不同Tg的丙烯酸酯共聚物乳液共混,制备共混乳胶膜。通过表面接触角测试、SEM和AFM等测试,详细探讨了成膜温度、热处理条件、两共混组分的Tg差异和成膜基材等因素对硅丙共混乳液自组织形成梯度结构的影响。测试结果表明,1.适当提高成膜温度,有助于共混乳胶膜中两组分发生自分层,产生梯度结构。2.以玻璃为成膜基材,当P(TRIS-co-MMA)组分不能参与成膜(即成膜温度为25℃和45℃)时,退火有利于乳胶膜中的含硅组分进一步迁移,使得乳胶膜两接触表面的表面能差异继续增大,并且沿断面方向上Si成梯度化分布；当P(TRIS-co-MMA)组分能够参与成膜(即成膜温度为55℃和65℃)时,退火对两接触表面的表面能影响不大。3.共混组分的Tg差别越大,其共混乳胶膜的自组织迁移效果越明显。4.成膜基材不同,会影响含硅组分的迁移方向,从而对乳胶膜的表面性能和梯度结构造成影响,并且共混组分的Tg差别会对含硅链段向两接触表面的迁移程度造成影响。更多还原

【Abstract】 Gradient polymer blend materials through self-organization have attracted increasing attention of many investigators recently. Due to one component in blends having special functional groups, this component could self-organize to the surface of blend films during film-formation process or annealing process, and accordingly, a film surface with special properties is obtained. Organosilicone acrylate polymers have much lower surface free energy than non-organosilicane acrylate polymers, so self-organization will happen during the film-formation of their latex blends under effects of surface free energy. Finally, an organosilicone acrylate polymer material with gradient film structure is obtained. In this gradient material, one surface side of the blend film exhibits special surface properties, such as antifouling property, self-cleaning property, water-resistance and oil-resistance, whereas, the other surface side shows good adhesionIn this theses, firstly, a reactive organosilicone monomer mathacryloxypropyltris (trimethlsiloxy)silane(TRIS),was synthesized by substitution reaction between math acryloxypropyltrimethloxysilane(KH-570) and chlorotrimethylsilane (CMS).Not only the hydrolysis problem of KH-570 was solved in the process of emulsion polymerization, but also -Si(CH3)3 group was induced into the molecular, that could effectively increase the content of organosilicon of the latexes prepared, and provided the copolymer excellent water-resistance.Secondly, with sodium lauryl sulfate(SDS) and sodium 3-alyoxy-2-hydroxy propane sulfonate(COPS-1) as composite emulsifier system, methylmethacrylate and self-made monomer TRIS were used as raw materials, a series of TRIS/MMA copoly-mer latexes were prepared by seeded semibatch emulsion polymerization. A PTRIS latex and a PMMA latex were prepared by batch emulsion polymerization. The properties, average particle size and distribution, particle morphology and Tg of these latexes were tested, respectively. The results indicated that as the mass content of TRIS increased, the latexes’stability decreased, the average particle size increased while the distribution and Tg platform boarded. In the end, the TEM photograph showed that the copolymer latex particle had a special morphology with three layers. The free energy of these copolymer films decreased as the content of organic silicone decreased, and all of them provided excellent water-resistance.Finally, polysilane-polyacrylate gradient films were prepared by emulsion blend method through self-organization. How the factors, such as film-formation temperat-ure, Tg difference, heat treatment and film formation matrix influenced on the formation process of self-organization of polysilane-polyacrylate gradient films were discussed in details with the characterizations of surface contact angel method, SEM, TEM and so on. The results indicated that increasing the film-formation temperature could promote the two components migrate in latex blend. Take Samplel for example, when the film-formation was lower than the Tg of P (TRIS-co-MMA), annealing could help organic silicone segment migrate, that could increase the difference between the two surface free energies of the film, while when the film-formation was higher than the Tg of P (TRIS-co-MMA), annealing had Iittlie influence with the two surface free energies. The larger the Tg difference between two components was, the more obvious the self-organization effect appeared. In the end, matrix kind could influence the migrate direction,degree of organic silicone segment and the gradient structure.更多还原