SYNTHESIS OF POLY(METHYL METHACRYLATE)-SILICA NANO-COMPOSITES. II. POLY[METHYL METHACRYLATE-block-(METHYL METHACRYLATE-co-2-HYDROXYETHYL METHACRYLATE)]

ABSTRACT

One kind of poly(methyl methacrylate [MMA]-block-2-hydroxyethyl methacrylate [HEMA]) block copolymer and two kinds of poly[MMA1-block-(MMA-co-HEMA)] block-random copolymers were synthesized by atom transfer radical polymerization. Then, poly(methyl methacrylate) [PMMA]-silica nano composites were synthesized by blending perhydropolysilazane (PHPS: NN-110) and block or block-random copolymers in 1,4-dioxane and casting the blend solutions. All composite films were transparent. Silica and organic domains were microphase separated in the composites. The effects of PHEMA content and blend ratio of PHPS to hydroxyl group on the microphase separation were investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The thermal properties of the composites were investigated by differential scanning calorimetry (DSC) and thermal gravitic analysis (TGA).     

SYNTHESIS OF POLY(METHYL METHACRYLATE)-SILICA NANO-COMPOSITE

ABSTRACT

Transparent organic/pre-ceramic composite films of poly(methyl methacrylate) [PMMA] and perhydropolysilazane [PHPS] were synthesized by blending poly(methyl methacrylate-co-2-hydroxyethyl methacrylate) [P(MMA-co-HEMA)] random copolymers and PHPS. In the blend films, P(MMA-graft-PHPS) graft copolymers were formed, PMMA and PHPS were microscopically phase-separated in the solid state. Morphology of the microphase separation was investigated by transmission electron microscopy by changing HEMA content of the random copolymers and blend ratio of PHPS to HEMA. To convert PHPS to silica glass, the blend films were calcinated at 100°C. The morphology of the microphase separation of the films was not changed by the calcinations; the calcinated films were transparent. When the molar content of HEMA of P(MMA-co-HEMA) and the molar content of PHPS to HEMA in feed were 14.5% and 150%, respectively, the morphology was well ordered lamellae of PMMA and silica.     

由光敏性全氢聚硅氮烷制备透明高硬Si—O微/纳米结构压印模板

面向可用作压印模板的透明高硬微/纳米结构的低成本制备,无机高分子全氢聚硅氮烷用甲基丙烯酸(2-异氰酸基乙酯)进行光敏改性,经FTIR,1H-NMR,13C-NMR等手段表征,推断获得的是甲基丙烯酸酯化的全氢聚硅氮烷(MPHPS),并以此为原料,用一种含氟聚合物(FP)模板,施加0.1～0.4 MPa的压力,紫外压印制备MPHPS的微结构,发现增加压力,压印复制效果提高,0.23 MPa可以完全复制FP模板的微结构.此外,在0.4 MPa的压力下也制备了分辨率为90 nm,70 nm的纳米级结构.随后在碱性条件下室温水解,MPHPS聚合物结构转化为Si—O无机结构,最终获得透明高硬结构,硬度4.5×103MPa,弹性模量115×103MPa.