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標題: | 形狀記憶聚氨酯:合成,結構與性能 Synthesis, Structure and Property of Shape Memory Polyurethane |
作者: | Chien-Hsin Wu 吳建欣 |
指導教授: | 鄭如忠(Ru-Jong Jeng) |
關鍵字: | 形狀記憶,聚氨酯,規則樹枝狀高分子,交替式合成,有機/無機混成,金剛烷, shape memory,polyurethane,drndron,organic/inorganic hybrid,iterative synthesis,adamantane, |
出版年 : | 2016 |
學位: | 博士 |
摘要: | 透過單體設計,製備出一系列構築單元類似,構型相異的聚氨酯硬鏈段,接枝在高結晶性的聚己內酯(PCL)軟鏈段以及二異氰酸酯MDI 為主體的聚氨酯側鏈。產物包括(1)可交聯軟鏈段聚氨酯SPU,(2)化學及無機交聯聚氨酯CPU-A 與CPUS,(3)線性側鏈聚氨酯CPU-LG,(4)規則樹枝狀側鏈聚氨酯CPU-DG,(5)含金剛烷規則樹枝狀聚氨酯APU,(6)含金剛烷規則樹枝狀聚氨酯封端聚氨酯EPU,並與傳統的線性聚氨酯LPU 探討硬鏈段構型對聚氨酯機械性質的影響。開發出反應選擇性單體4-isocyanato-4’ (3,3-dimethyl-2,4 -dioxo-azetidino)diphenylmethane (IDD)作為構築單元,將雙苯環高分子重複單元逐步反應製備出末端長碳鏈的高極性巨分子,控制成長出一系列單分佈的線性與樹枝狀的poly(urea/maloanmides)。利用IDD 製備的聚氨酯短側鏈,成為聚氨酯後修飾的反應點:比起傳統聚氨酯化學交聯生成脲基甲酸酯鍵結,改善反應控制性與監控性,降低反應溫度。透過改質高分子側鏈,聚氨酯產生有別於傳統聚氨酯的物理或化學交聯,改變聚氨酯軟鏈段與硬鏈段結晶性,影響材料對溫度的相轉移,並呈現出迥異的機械性質。根據材料特性選出具有潛力應用於形狀記憶材料的聚氨酯,研究形狀記憶行為。 Shape memory polyurethanes (SMPUs) were prepared from similar chemistry but in different polymer architectures with crosslinkers. The dual functional building block 4-isocyanato-4’ (3,3-dimethyl-2,4 -dioxo-azetidino)diphenylmethane (IDD) was selected to prepare poly(urea/maloamid) and a chain extender of PUs under mild condition without resorting to painstaking protection-deprotection or activation methodology. A diol compound with reactive azetidine-2,4-dione group was prepared and introduced as side chain moieties of poly(ε-caprolactone) (PCL) based polyurethane (SPUs). The SPUs with reactive pendants were crosslinked by 1,6-diaminohexane, or modified by an alkoxysilane (3-aminopropyltriethoxysilane, APTS) followed by a sol-gel reaction to bring about crosslinked PUs for shape memory applications. Thermal and mechanical properties of the crosslinked SPUs are strongly dependent on the chemical structure of the interchain-linker between the polymer chains. In addition, SMPUs comprising dendritic (DG series) or linear (LG series) poly(urea/malonamide) hydrogen bond-rich side chains with uniform chain lengths, providing physical crosslinking interactions to PUs. With the reactive functional group, azetidine-2,4-dione as the side chain of SPU to be a crosslinking site, different grafting ratios with various chain lengths of poly(urea/malonamides) were incorporated onto SPU. Consequently the physical crosslinking density could be adjusted. Via NMR, IR, EA, Mass and GPC analysis, we were able to confirm that the precise control of the poly (urea/malonamide) chain lengths were obtained. Phase transition temperatures of SMPUs were observed via differential scanning calorimeter (DSC). By introducing the chemically crosslinked structures, the deformed samples completely recovered to their original shape in less than 3 second without any deficiency during shape recovery tests. Shape recovery went up to 99% during cyclic thermomechanical tensile tests, indicating that the polyurethanes with chemical crosslinking effects exhibited higher impact than did the linear and dendritic side-chain polyurethanes. Consequently, these novel crosslinked polyurethanes with excellent shape-memory effect have been successfully developed in this work. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/48886 |
DOI: | 10.6342/NTU201603571 |
全文授權: | 有償授權 |
顯示於系所單位: | 高分子科學與工程學研究所 |
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