含八邊官能基之非結晶型多面體聚矽氧烷高分子複合材之合成與特性分析

Abstract

OS-POSS（octakis（dimethyl（phenethyl）siloxy）silsesquioxane）以及OA-POSS（octakis（dimethyl（4-acetoxyphenethyl）siloxy）silsesquioxane）兩種POSS衍生物的合成是利用octakis(dimethylsiloxy)silsesquioxane(一種Polyhedral Oligomeric Silsesquioxanes簡稱POSS)進行矽氫加成反應(hydrosilylation)反應，分別在POSS分子的八個角落，接枝上styrene以及4-acetoxystyrene兩種單體，而形成之新穎八角接枝多面體聚矽氧烷結構。此外，將合成出之OA-POSS利用hydrazine monohydrate進行水解後即可得到的產物，OP-POSS（octakis（dimethyl（4-hydroxyphenethyl）siloxy）silsesquioxane）。經由hydrosilylation反應後，POSS衍生物(OS-POSS, OA-POSS, and OP-POSS)的型態由原先結晶型固體[octakis(dimethylsiloxy) silsesquioxane(Q8M8H)]轉變為液態。DSC(微分掃描式熱分析儀)以及XRD(X光粉晶繞射儀)的分析指出：此三種新穎POSS衍生物雖然分子量並未很高，但其分子內存在類似高分子性質的玻璃轉移溫度 (Tg點)且具有非結晶型繞射暈。 經由高分子溶液混掺(polymer blending)[OS-POSS與poly(styrene)混掺、OA-POSS與poly(4-acetoxylstyrene)混掺、以及OP-POSS與poly(4-vinylpyridine)混摻]可得含POSS之高分子奈米複合材。在這些複合材中，OA-POSS與poly(4-acetoxylstyrene)之間的偶極－偶極作用力(dipole-dipole interaction)，使OA-POSS達到最好的分散性[由TEM(穿透式電子顯微鏡)圖得知]。

OS-POSS and OA-POSS were synthesized by hydrosilylation of octakis(dimethylsiloxy)silsesquioxane (Q8M8H) with styrene and 4-acetoxystyrene. OP-POSS was prepared by hydrazinolysis of OA-POSS with hydrazine monohydrate. The chemical structures of three POSSs were characterized by FTIR, 1H-NMR and MALDI-TOF mass spectra. We found that hydrosilylated POSS products became liquid in comparison with crystal Q8M8H. By DSC thermograms and XRD analyses, three amorphous POSS products exhibit polymer-like glass transitions and amorphous halos. With weaker intermolecular interaction of amorphous POSSs, POSS-based nanocomposites can be prepared by solution blend with polymer matrices such as OS-POSS with polystyrene, OA-POSS with poly(4-acetoxystyrene), and OP-POSS with poly(4-vinylpyridine). Among three intermolecular interaction, the dipole-dipole interaction can reach the best dispersion of OA-POSS with the medium strength to separate each other as shown in TEM images.