光學級高耐熱聚甲基丙烯酸甲酯共聚合物材料

Abstract

聚甲基丙烯酸甲酯於高分子材料間之透明性佳，質量輕常作為玻璃取代，耐候性佳，良好化學阻抗性，及高絕緣性。本研究藉由探討分子間作用力，調控聚甲基丙烯酸甲酯之耐熱性及降低吸濕性，此分子作用力包括剛硬結構物單體、氫鍵作用力單體、及奈米複合材料。透過此分子間作用力單體與丙烯酸甲酯進行共聚合反應，本研究分做三個主題討論： 1. 探討剛硬結構物作用力對於聚甲基丙烯酸甲酯之影響 製備出一系列poly(isobornyl methacrylate-co-methyl methacrylate) (PIBMA-co-PMMA)共聚合物，此共聚合物具有高耐熱及高透明性特性且低吸濕特性，透過剛硬結構物單體降低共聚合物材料自由體積，並同時達到共聚合物吸濕性，研究中進行分子量探討調控為射出成型用之材料，並進行發光二極管封裝材料試驗。 2. 氫鍵作用力 探討氫鍵作用力對於高分子材料差異，研究合成了poly(methylmethacrylate-co-cyclohexylmaleimide) (PMMA-co-PCHMI)共聚合物，探討CHMI含量對於共聚合物物化性差異，結果顯示導入此氫鍵作用力單體對於對於聚合物材料玻璃轉移度耐熱性提高，並且對於吸濕性上影響不多，此系列共聚合物材料添加1-30 wt% CHMI，並將此共聚合物設計為射出成型可用之高透明高耐熱之材料，其Tg > 146 ºC，分子量落於106，PDI < 1.56-1.78。 3. 多面體矽氧烷寡聚物(Polyhedral Oligomeric Silsesquioxane，POSS)共聚合物探討 本篇研究進行透過聚合方式製備出有機無機混成透明耐熱聚甲基丙烯酸酯材料，透過強氫鍵作用力之聚丙烯醯胺單體及多面體矽氧烷寡聚物進行共聚合，探討適當多面體矽氧烷寡聚物添加量下對於原有物性之影響，在不影響透明度物性下，研究探討其最適化點，研究藉由傅里葉轉換紅外光譜位移證實氫鍵產生作用力的變化。本實驗再導入聚丙烯醯胺單體，以動態機械分析儀觀察於多重氫鍵作用力下擬交聯的情況下，聚甲酯丙烯酸酯的儲存模數提高，阻尼相(tan δ)降低，並觀察到此材料相轉移變化玻璃轉移溫度點與示差掃瞄熱卡量計分析結果相近。

PMMA is a transparent polymeric thermoplastic material possessing colorless, good weather-resistance, high light transmittance, ultraviolet radiation, chemical resistance, dimension stability, and good insolating properties. In this study research the thermal resistant and the moisture absorption of the poly(methyl methacrylate) (PMMA). This study has investigated the results of the synthesis and characterization of the PMMA copolymers. These copolymers were MMA copolymerized with three kinds of comonomer, included the bulky effect, hydrogen-bond effect, and the inorganic effect. 1. Bulky structure of MMA monomer A series of PIBMA-co-PMMA copolymers was prepared using bulk copolymerization by using chain transfer agents to generate the heat-resistance and transparency required for use in injection molding. The results indicated that the fabricated copolymers displayed both lowered moisture absorption levels and excellent optical properties. This novel thermoplastic material was fabricated by copolymerizing isobornyl methacrylate (IBMA) monomer with methyl methacrylate (MMA), yielding a transparency greater than 90%, excellent thermal resistance, and a moisture absorption ratio lower than 0.5 wt%. Thus, these copolymers are attractive for potential applications in the polymer industry. 2. Hydrogen bong monomer effect monomer for PMMAcopolymer The random poly(methyl methacrylate-co-cyclohexylmaleimide) (PMMA-co-PCHMI) copolymers exhibiting the high glass-transition temperature (Tg) and high transparency was prepared in this study. We investigated the effects of the N-cyclohexylmaleimide (CHMI) content on the Tg behavior, moisture absorption, transmittance, and molecular weight of these copolymers. The results indicated that the hydrogen-bonding effect can facilitate the enhancement of thermal properties. Furthermore, the moisture absorption increased and the transmittance decreased when the CHMI content increased in most of the copolymers. In addition, we designed a tetrapolymer with lower moisture absorption and a higher Tg value than pure PMMA. These copolymers have the potential to replace pure PMMA in optical electric field applications. 3. The strong hydrogen bond and inorganic POSS effect In this study we prepared a series of PMMA-co-PMAAM-co-PMAPOSS random copolymers containing low amounts of MAAM and MAPOSS monomer units have been prepared through bulk polymerization. The incorporation of the bulky POSS monomer maintained PMMA’s excellent transmittance in the near-UV region and lower moisture absorption, while the hydrogen bonding of the MAAM monomer units hindered the free rotation of the PMMA copolymers and, thereby, enhanced the thermal properties. The PMMA copolymer incorporating 5 wt% PMAAM and 5 wt% PMAPOSS displayed an enhanced value of Tg (to 142 °C), a higher modulus, a higher water contact angle, and reasonable high transparency. Accordingly, such copolymers have potential uses in optical applications as replacements for PMMA homopolymers