功能化接枝奈米矽片及分子接枝PMMA/PNIPAAm 與複合材料應用

Functionalization of Nano Silicate Platelets for Molecular-Level PMMA/PNIPAAm Nanocomposites

李政韋(Cheng-Wei Li)

指導教授 ： 林江珍

國立臺灣大學/工學院/高分子科學與工程學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201701936

摘要

奈米矽片(NSP)是由層狀蒙托土(Na+-MMT)脫層而得。本實驗室已開發透過奈米矽片邊緣之矽醇基 (≡Si—OH) 與有機分子連接形成共價鍵，形成帶胺基、壓克力官能基及高分子如溫度敏感型聚N-異丙基丙烯醯胺(PNIPAAm)的有機-無機的複合材料。本研究旨在開發更簡要之製程來合成由共價鍵連結之NSP 奈米複合材料及其應用,由一步驟的方式，我們可將壓克力官能基透過酯交換反應接上NSP形成NSP-acrylate，再由自由基聚合反應來合成NSP-acrylate-PMMA。
導入NSP-acrylate與NSP-acrylate-PMMA進入壓克力樹酯製備成光學膜。透過NSP上的官能基與壓克力樹酯進行交聯，發現僅添加0.3wt%的NSP-acrylate-PMMA可大幅將光學膜之硬度由4H提升到9H。將NSP-acrylate-PMMA透過混摻導入PMMA,發現添加1wt%即可將PMMA的玻璃轉移溫度(Tg)由112 ºC提升到123ºC。
於另一系統中，我們開發一簡要的製程將具有溫敏性的PNIPAAm透過共價鍵接在NSP上。壓克力官能基透過醯胺鍵鍵結上NSP-amine形成NSP-a-acrylate再以自由基反應合成 NSP-a-acrylate-PNIPAAm，經由新製程所形成的產物僅於低溫分散在水中，高溫下則會聚集沉澱，為一具有最低臨界聚集溫度(LCAT)的複合材。

關鍵字

奈米矽片 ； 有機無機複合材 ； 共價鍵 ； 硬度 ； 玻璃轉移溫度 ； 最低臨界聚集溫度

並列摘要

Nanoscale silicate platelets (NSP) were previously prepared from the newly developed exfoliation of sodium silicate clays (Na+-MMT) by ionic exchange reaction.
Due to the silanol groups (≡Si-OH) on the edges of NSP, the organic group such as amine group, acrylic group and polymers such as poly(N-isopropylacrylamide) (PNIPAAm) was covalently tethered to NSP to generate a new class of organic-inorganic hybrid. The object of this research is to develop a convenient method for synthesizing covalently functionalized NSP and applying in NSP nanocomposites. With one-step procedure, acrylic group was grafted onto NSP via transesterification to produce NSP-acrylate, further PMMA tethered to NSP-acrylate through free radical polymerization to afford NSP-acrylate-PMMA. The synthesized NSP-acrylate and NSP-acrylate-PMMA were added to acrylic resins for UV-curing to yield NSP-nanocomposite films. The hardness of molecular composite films was dramatically increased from 4H to 9H by loading of only 0.3 wt% NSP-acrylate-PMMA while maintaining high transparency (91%) of the film. Moreover, NSP-acrylate-PMMA was blended with PMMA to have the glass transition temperature (Tg) chages from 112ºC to 123ºC with only 1 wt% loading of NSP-acrylate-PMMA.
In another system, we developed a facile method for tethering PNIPAAm onto NSP, the acrylic group grafted onto NSP-amine with amide bond to fabricate NSP-a-acrylate then tethered PNIPAAm by free radical polymerization. In short, we present a practical method for functionalized NSP for the purposes of increasing hardness of the films and Tg for PMMA. In addition, the covalent tethering of PNiPAAm onto NSP generated the property of lower critical aggregation temperature (LCAT).

並列關鍵字

NSP ； organic-inorganic nanocomposites ； covalent bond ； hardness ； Tg ； LCAT

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