含羟基苯乙烯/甲基丙烯酸甲酯无规共聚物薄膜的界面行为

Interfacial behavior of hydroxy-containing styrene/methyl methacrylate random copolymer film

通过自由基聚合方法制备一系列含侧羟基的不同苯乙烯含量的苯乙烯和甲基丙烯酸甲酯的无规共聚物(SMMA-r OH),并与含端羟基的不同苯乙烯含量的无规共聚物(SMMA-t OH)对比,研究化学改性硅片表面的界面行为。采用红外光谱(FT-IR)、核磁共振波谱(NMR)等手段进行SMMA-r OH的结构表征。通过测量聚苯乙烯(PS)和聚甲基丙烯酸甲酯(PMMA)两种均聚物、无规共聚物膜的水相与油相接触角得到极性和非极性表面能,计算得到PS和PMMA均聚物与无规共聚物间的界面能,通过引入表面能极性占比参数,对比羟基接枝前后含羟基无规共聚物的表面能。结果表明:在SMMA-r OH中苯乙烯摩尔分数为54%时,PS与无规共聚物间的界面能和与PMMA无规共聚物间界面能相等。SMMA-r OH退火后表面基底覆盖率较高,相比于SMMA-t OH在洗涤前后的界面行为变化较小。证明侧羟基无规共聚物作为基底更适用于嵌段共聚物引导组装的中性基底。

A range of different content of styrene and methyl methacrylate of side-chain hydroxy-containing random copolymers（ SMMA-r OH） were prepared by radical polymerization. Contrasting with different content of styrene and methyl methacrylate of end-hydroxyl-functionalized random copolymer（ SMMAt OH）,the interfacial behavior of chemical modification silicon wafer surface was investigated. The structure of SMMA-r OH was characterized by Fourier transform infrared spectrum（ FT-IR） and unclear magnetic resonance（ NMR）. The surface energy of random copolymer,polystyrene（ PS） and polymethyl methacrylate（ PMMA） homopolymer was obtained by measuring contact angle of polymers,then the interfacial energy between PS and PMMA homopolymer with random copolymer was calculated. For comparison of the surface energy of hydroxy-containing random copolymer before and after hydroxyl grafting,the surface energy polarity ratio was introduced. Results showed that the mole fraction of styrenein SMMA-r OH was 54% and interfacial energy between PS with random copolymer and PMMA with random copolymer was equal. And compared to the SMMA-t OH,surface coverage of SMMA-r OH was higher and interfacial behavior change was smaller. It was proved that as the neutral substrate,side-chain hydroxy-containing random copolymer was more suitable for block copolymer guided assembly.