合成含甲基丙烯酸乙酯之規則樹枝狀高分子應用於光交聯蜂窩狀孔洞薄膜

Abstract

本研究使用具有反應選擇性單體4-isocyanato-4＇-(3,3-dimethyl-2,4-dioxo-azetidino)-diphenylmethane (IDD) 為構築單元，與壓克力基的單體2-hydroxyethyl methacrylate (2-HEMA) 進行反應，得到末段具有壓克力基的樹枝狀分子構築單元G0.5-MA，再經由與Diethylenetriamine (DETA)和重複單元逐步進行收斂式反應，製備出不同代數，末端具有多個壓克力基的規則樹枝狀poly(urea/malonamides)高分子(G1.0-G2.5)，並經由多種結構鑑定法確認規則樹枝狀分子具有高密度雙鍵且精準的結構。而藉由改質G0.5-MA和十八碳系列的樹枝狀分子G1.5-C18，分別合成具有二醇結構的A-G0.5-MA和A-G1.5-C18，並與Methylene diphenyl isocyanate (MDI)以不同的比例聚合形成PU-PMA，而PU高分子結構中的雙親性樹枝狀高分子能穩定水分子及高分子溶液間的界面，並控制水分子整齊排列於溶液表面的自組裝現象，等到水分子及溶劑完全揮發即得到規整的孔洞結構。藉由混摻適當比例的樹枝狀分子G1.5-MA和G2.5-MA以及光起始劑CQ (Camphorquinone)、EDMA (Ethyl-4-dimethylaminobenzoate)、AIBN (Azobisisobutyronitrile)，使得形成蜂窩狀孔洞結構同時具有可光交聯的性質。而在適當的光波長照射之下，能夠使膜上的雙鍵結構進行光交聯，並在浸泡於交聯前無法承受之特定溶劑後，仍在膜上維持孔洞結構。本研究成功製備出光交聯之蜂窩狀孔洞膜，使原先較為脆弱之孔洞膜具有更為強健的溶劑抗性。

In this study, a series of dendritic diluents with each molecule featuring for multiple photo-crosslinkable moieties were developed. Through the convergent route, well-defined poly(urea/malonamide) dendrons of different generations (G0.5~G2.5) with peripheral methacryloyl groups were synthesized by using a building block with selective reactivity such as 4-isocyanato-4'-(3,3-dimethyl-2,4-dioxo-azetidino) -diphenylmethane (IDD). These newly synthesized dendrons were utilized as dendritic diluents for polyurethanes. Subsequently, honeycomb-array would able to be prepared in the presence of the diluents, and acrylate-containing dendritic polyurethanes (PU-PMA) which were synthesized based on amphiphilic dendrons and methylene diphenyl isocyanate (MDI). Consequently, robust honeycomb-like films with solvent resistance were realized after the exposure of ultra-violet (UV) light, i.e. photo-crosslinking.