以總體聚合法製備壓克力／黏土奈米複材及其性質探討

Preparation and Characterization of Poly(methyl methacrylate) /Clay Nanocomposites by Bulk Polymerization

張銘軒(Ming-Hsuan Chang)

指導教授 ： 蔡宗燕

中原大學/理學院/化學研究所/碩士(2018年)

https://doi.org/10.6840/cycu201800609

摘要

本研究主要探討，以總體聚合法製備具高熱穩定性的聚甲基丙烯酸甲酯奈米複材（Highly thermal stability of poly(methyl methacrylate) nanocomposite），其組成包含無機層狀材料、起始劑BPO、甲基丙烯酸甲酯單體。無機層狀材料為天然黏土層狀材料 （Clay）。選用三種不同有機長碳鏈改質劑天然黏土做有機改質劑，分別是椰油醯胺丙基甜菜鹼、椰油醯兩性基二丙酸二鈉和氯化苄二甲烴銨利用離子交換法將天然黏土進行有機化改質，增加其與高分子基材的相容性，以少量無機層狀材料作為添加材混入聚甲基丙烯酸甲酯。另外探討起始劑濃度、固化時間、不同比例的材料的添加等，對聚甲基丙烯酸甲酯的影響。利用廣角X光繞射儀觀察無機層材之層間距變化，以掃瞄式電子顯微鏡觀察黏土表面型態的變化，並藉傅立葉轉換紅外線光譜儀鑑定其改質土之有機與無機的官能基，接續以熱重分析儀分析改質土中改質劑的插層量。
接著將聚甲基丙烯酸甲酯/黏土奈米級複合材料，以廣角X光繞射光譜儀（WXRD）、穿透式電子顯微鏡（TEM）觀察其分散性，在P-CL120-K2體系中分散型態為島型脫層。熱性質以P-CL120-K2-2wt%之熱裂解溫度最高提升57.07 °C，自240.20 °C提升至297.21 °C。機械性質方面，以動態機械分析儀（Dynamic Mechanical Analyzer, DMA）檢測儲存模數是P-CL120-HP-0.5wt%提升最多，增加471 MPa，由1491 MPa提升至1784 MPa。光學性質方面，以紫外光譜儀-可見光譜分析儀P-CL120-BEN-0.5wt%在可見光波段550 nm，穿透率下降14.68%，從92.07%下降至77.34%。而P-CL120-K2系列在UVB波段320 nm下降70.07%~83.94%而UVA 波段375 nm則下降50.62%~80.81%，顯示K2改質劑對UV波段有明顯的吸收。此外，上述的結果顯示了PMMA/Clay複合材料用於LED封裝的潛力。

關鍵字

總體聚合法 ； 甲基丙烯酸甲酯 ； 天然黏土

並列摘要

The potential to improve the mechanical, thermal, and optical properties of poly (methyl methacrylate) (PMMA)/montmorillonite nanocomposites by bulk polymerization using organic modified clay, were investigated. Pristine sodium montmorillonite clay was modified by using (cocamidopropyl Betaine, HP) and (disodium cocoamphodipropionate, K2) and (benzalkonium chloride, BEN), via ion exchange to enhance the compatibility between the clay platelets and the PMMA polymer matrix. The morphology and modification of clay have been confirmed by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and Fourier Transform Infrared spectroscopy (FT-IR) to identify the functional group in modified clay. The dispersion morphology of PMMA nanocomposites has been confirmed by XRD and transmission electron microscopy (TEM) analysis. Thermal and Mechanical properties of PMMA nanocomposites were investigated by using a thermal gravimetric analyzer (TGA), a dynamic mechanical analyzer (DMA), respectively.
In this study, three different types of modified clays (CL120-HP, CL120-K2, and CL120-BEN) were applied to prepare the series of PMMA/clay nanocomposites. From the TEM results, it is confirmed that P-CL120-K2-2wt% nanocomposite displayed exfoliated morphology. Conversely, P-CL120-HP-2wt% and P-CL120-BEN-2wt% nanocomposites displayed intercalated morphologies. The decomposition temperature (Td) of P-CL120-K2-2wt% is increased 57 ℃compared to pure PMMA. The PMMA nanocomposites transmission rate is decreased in the visible light region as clay content increased but maintained an optical transmission of approximately 77.50%. The UV resistance of P-CL120-K2-2wt% was massively decreased by 83.9% from 84.9% to 0.93%. The storage modulus of P-C120-HP-0.5wt% was increased by 20% as compared to pure PMMA. Moreover, these results suggest the potential of the PMMAcomposites for LED packing.

並列關鍵字

bulk polymerization ； montmorillonite ； layered silicates ； methyl methacrylate

參考文獻

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