有機/無機多面體矽氧烷寡聚物 奈米複合材料

Abstract

本研究中，針對含有苯乙烯官能基之多面體矽氧烷寡聚物(以下簡稱Styryl-POSS )之性質探討，合成出一系列的共聚物;其中包含了:苯乙烯共聚甲基丙烯醯胺、甲基丙烯醯胺共聚Styryl-POSS、苯乙烯共聚Styryl-POSS以及苯乙烯、甲基丙烯醯胺、Styryl-POSS三聚物。對於每個共聚物系統，改變不同組成，觀察其性質改變，最後再探討不同系統中，Styryl-POSS添加量所造成的影響。由於POSS奈米結構的效應，所以我們只需加少量Styryl-POSS於系統中即可造成性質變化。本篇研究將主要針對加入甲基丙烯醯胺於三聚物中，其極性官能基與POSS產生作用力，進而得到較佳的熱安定性。 由1H-NMR分析中，可清楚鑑定出各系統之組成百分比，並可求出共聚物之單體反應常數(r1、r2)，再由13C-NMR光譜中，鑑定出此一系列共聚物之結構，而29Si-NMR則可看出Si化學位移(-66與-67ppm)皆相近，表示POSS籠狀結構並未明顯受到極性作用而變形;並利用FT-IR做官能基的鑑定並比較不同系統間的光譜變化，尤其觀察甲基丙烯醯胺的NH2(3200~3500cm-1)、C=O(1653cm-1)與POSS籠狀(1108cm-1)結構吸收峰的變化;而DSC證明三聚物由於極性作用力使玻璃轉移溫度(Tg)較共聚物穩定，不會因POSS含量增加而降低;再由TGA證實其熱重損失溫度(Tdec)在三聚物相對於共聚物時明顯提升了40oC;最後利用X-ray說明POSS在共聚後並未有奈米相的聚集情形。

In this study, the styryl polyhedral oligomeric silsesquioxanes (POSS) containing polymers were synthesized and indentified. These copolymers include: poly(styrene-co-methacrylamide), poly(methacrylamide-co-POSS), poly(styrene-co-POSS) and poly(styrene-co-methacrylamide-co-POSS). We change different compositions of each copolymer and study their properties. Finally, we discuss the influence of POSS content within different copolymers. We can just incorporate small amounts of POSS with polymers and get obvious changes of property as a result of POSS nano-cage. In this study we focus on enhanced thermal stability due to polar amide group of methacrylamide. From analysis of 1H-NMR, we can identify mole composition of each copolymer and terpolymer. Then we calculate monomer reactivity ratio (r1, r2) from copolymer composition equation. From analysis of 13C-NMR, the structure of these copolymers and terpolymer are characterized. From 29Si-NMR spectrums, the cage chemical shifts of POSS (-66 and –67 ppm) don’t change. This means cage structure of POSS does not deform by amide polar forces. From analysis of FT-IR, we compare different absorbances of functional groups between different copolymer systems especially in amide group (3200~3500 cm-1) and carbonyl group (1653 cm-1). And the Si-O absorbances of terpolymer broaden. From analysis of DSC, we find that the glass transition temperatures (Tg) of terpolymers do not decrease with increasing content of POSS through polar amide group in contrast to copolymer systems. From TGA curves, the thermal decomposition temperatures (Tdec) of terpolymers exceed 40oC than that of copolymers. Finally, X-ray curves show that there isn’t any aggregation of nano-phases.