高折射奈米有機無機壓克力混成複合材料與聚氨酯改性環氧樹脂複合材料之性質研究

本論文為有機/無機高分子混成複合材料與聚氨酯改性環氧樹脂複合材料之研究。分成四個部分進行探討，第一部份以四氯化鈦(TiCl4)作為起始劑通過溶膠-凝膠反應合成二氧化鈦(TiO2)。然後將丙烯酸(AA)引入系統中進行表面改性，防止奈米顆粒團聚且提供壓克力官能基團以利應用。熱重分析儀(TGA)分析顯示，所製備的TiO2奈米顆粒之熱裂解溫度為200℃，且AA改性TiO2之重量損失與添加的AA量成正比。由傅立葉轉換紅外線光譜儀(FTIR)分析，觀察到羧酸基和羥基之間的縮合或螯合在表面改性中起重要作用，由FTIR監控分析顯示完成反應時間需要48小時。為了確定最佳的反應條件，於25℃和50℃下進行AA改性TiO2合成反應，在25℃下添加的丙烯酸越多，對TiO2顆粒避免團聚的保護作用就越好。觀察AA改性TiO2照片，當TiO2與AA的莫耳數比等於1:6或1:14時在溫度升至50°C下皆發生團聚。然而有適量AA的T1A10H仍能保持球狀且奈米級(10-15 nm)結構，並在50°C下很好地分散在水溶液中。第二部分為探討多官能基之壓克力樹脂以及與奈米TiO2摻混成複合材料後之性質研究，以紫外光硬化的方式進行多官能壓克力樹脂固化後性質分析，觀察到以三官能基季戊四醇三丙烯酸酯(PETA)改性之聚氨酯壓克力樹脂(MUA)擁有最佳熱性質，熱裂解溫度(Td10%)可達386℃。第三部分以聚氨酯壓克力樹脂(MUA)混成奈米TiO2複合材料進行研究，奈米複合材料顯示出高折射率和良好的熱性質。以異丙氧基鈦(TTIP)為起始劑，在限水環境中合成TiO2，並以3-甲基丙烯醯氧丙基三甲氧基矽烷(MSMA)進行TiO2表面改性，使表面包含疏水基團，增加與MUA樹脂的相容性，提高其折射率。通過動態光散射粒徑分析儀(DLS)進行測量，MSMA-TiO2有機/無機複合材料的最高折射率可以達到1.71，由TGA分析熱裂解溫度(Td 10%)可達415℃。第四部份為探討聚氨酯改性環氧樹脂應用於有機甘蔗纖維與無機岩石添加物之性質分析。這項研究分析了生物添加劑對動態力學性質，由結果顯示添加未改性的生物添加劑後，生物添加劑的含量與tanδ峰值之間存在不規則的趨勢。由於結果不一致，很難得出任何可靠的結論。因此，使用3-環氧丙氧基丙基三甲氧基矽烷(GPS)偶合劑對生物添加劑甘蔗渣進行了改性，以增強其相容性。結果顯示，當增加生物添加量時，tanδ峰值在一定範圍內線性下降(R2>0.99)。但是由於線性模型的截距值和其他問題，因此使用對數分析有更好地趨勢(R2>0.95)。與tanδ值不同，每增加10wt%的甘蔗渣，IPN的Tg線性降低約5℃。基於這些發現，推測GPS不會在高分子基材和生物添加劑之間產生任何共價鍵。相反，偶合劑通過均勻分散生物添加劑並減少這些生物添加劑的團聚來改善界面。研究無機岩石添加物觀察到3-氨基丙基三乙氧基矽烷(APS)改性環氧樹脂(AE)/岩石複合材料撓曲強度皆高於APS改性聚氨酯交聯環氧樹脂(APU-EP)/岩石複合材料，主要是因AE主鏈段為線性，分子量也較小，分子較易浸潤(wetting)岩石中，岩石表面能有良好的樹脂包覆，使複合材料撓曲強度較高，而值得注意的是，APU-EP雖然有較多的Si-OMe基團，但因聚氨酯交聯環氧樹脂(PU-EP)分子量也較高，使得分子間不易形成鍵結，導致撓曲強度低於AE。AE/岩石複合材料於岩石含量達到40wt%擁有最大值，可達28.5MPa，而APU1000-EP/岩石複合材料與APU2000-EP/岩石複合材料最大值則在岩石含量達50wt%分別為24.3MPa與20.2MPa。

關鍵字

二氧化鈦；聚氨酯壓克力；表面改性；混成材料；折射率；熱穩定性

並列摘要

In this study, organic and inorganic polymer composite were synthesized and researched. The first part, titanium tetrachloride (TiCl4) served as the precursor to synthesize amorphous titanium dioxide (TiO2) via a sol-gel reaction. Acrylic acids (AA) were then introduced into the system for surface-modification so as to provide not only the protection from aggregation but also hydroxyl groups to react with the functional groups for further applications. Thermal gravimetric analysis (TGA) showed that the thermal decomposition temperature of as-prepared TiO2 nanoparticle was 200°C and the weight loss of AA-modified TiO2 was linear corresponding to the amount of AA added. From FTIR, we found that either condensation or chelating between the carboxylic acid groups and hydroxyl groups plays an important role in the surface modification. FTIR analysis also suggested that 48 hours was required for completing the reaction. The synthesis of AA-modified TiO2 was operated at both 25°C and 50°C in order to determine the optimized reacting condition. At room temperature, the more acrylic acids added, the better the protection of the TiO2 particles from coagulation. When the temperature was raised to 50°C with the AA-modified TiO2 with a molar ratio of TiO2 to AA equal to 1:6 or 1:14, neither T1A6H nor T1A14H could preserve the original nanostructure under 50°C because of the lack of protection or the occurrence of over-polymerization, respectively. However, the T1A10H, with just the right amount of AA, remained spherical, nanosized (10-15 nm) and well-dispersed in aqueous solution under 50°C. The second part was the UV-curable multiple functionality acrylate resins mixed with high refractive index TiO2 nanoparticles are proposed and designed to meet the requirements of light-emitting diode (LED) package material. The obtained novel LED package material is expected to exhibit high refractive index (>1.6), high thermal stability (thermal decomposition temperature>400℃) and high light transmission (>92%). The third part, the UV-curable multi-functional urethane acrylate resin (MUA) was prepared through condensation reaction by isophorone diisocynante (IPDI), pentaerythritol triacrylate (PETA). The TiO2 was synthesized via non-aqueous and sol-gel process and then employ 3-(trimethoxysilyl)propyl methacrylate (MSMA) modification of the TiO2 surface not only contain hydrophobic group increased compatibility with MUA resin but also enhance the refractive index of the resins. The MUA structure was characterized by Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). The characteristics of the TiO2 and MSMA-TiO2 were measured by means of dynamic light scattering (DLS). The highest refractive index of the organic–inorganic hybrid material can reach 1.71 and the thermal properties of the cured coating were investigated by means of thermal gravimetric analysis, with the decomposition temperature (Td 10%) reaching up to 415℃. The fourth part, investigated the effect of bio-additives on dynamic mechanical properties of IPNs. The results show that the neat PU-EP, without bio-additives, has a stable interpenetrating polymer network represented by its singular sharp tan δ peak. After adding unmodified bio-additives, there is an irregular trend between bio-additive amounts and tan δ peak value. It is difficult to derive any solid conclusions on account of the inconsistent results. Thus, the bio-additives, sugarcane bagasse, were modified using a 3-glycidoxypropyltrimethoxysilane (GPS) coupling agent to enhance its compatibility. The results show tan δ peak value decreased linearly at certain range when increasing bio-additive amounts (R2>0.99). On the other hand, the flexural strength of 3-aminopropyl-trimethoxysilane (APS) modified epoxy resin (AE)/sand composite was higher than that of APS modified polyurethane cross-linked epoxy (APU-EP)/sand composite, owing to the AE main chain was linear and the molecular weight was smaller, the molecules were easier to wetting in the sand, and the sand surface can be wetting well, which makes the AE/sand composite higher than APU-EP/sand in bending strength.