- 學位論文
靜態與動態環境對高分子紫外光固化之影響
The Influence of Static and Kinetic Environments on Polymer UV-Curing
摘要
本研究為探討三官能基自由基樹脂及環氧系單體陽離子光固化系統於恆溫條件下靜態及動態光固化所產生之差異。自由基光固化系統將具有三個壓克力基之Trimethylolpropane triacrylate (TMPTA)加入裂解型光起始劑HMPP，陽離子光固化系統則是將具有環氧基之3,4-Epoxycyclohexylmethyl-3,4-cyclohexanecarboxylate (CELLOXIDE 2021P)加入路易士酸光起始劑UVI 6976後分別配置不同濃度再曝照紫外光形成網狀交聯結構。 固化過程以Photo-DSC亦稱為DPA (Double Beam Photocalorimetric Accessory)恆溫靜置下偵測反應放熱數值，換算得熱能轉化率，代入Kamal方程式；Real-time FT-IR則以穿透式掃描外加紫外光設備，藉由特徵峰與標準峰比值的變化換算得到其轉化率，亦代入Kamal方程式並輔佐DPA進行靜態光固化的數據比較；而流變儀於光固化過程中，自由基及陽離子樹脂在動態(dynamic)狀態產生黏彈性指標儲存模數(G’)之轉化率，代入Malkin and Kulichikhin方程式，則為動態光固化動力學數據。 自由基及陽離子光固化系統於靜態量測中(DPA、RTIR)皆觀察到在恆溫環境下添加光起始劑濃度存在一臨界值；動態量測(流變儀)發現自由基系統亦有一極限濃度存在並且具有Trommsdorff effect，陽離子系統固化過程G’∞會因鏈成長聚合過程中路易士酸光起始劑之中間產物受到干擾使G’增長受限。
並列摘要
The differences of static and kinetic behaviors under constant temperature while use three functional radicals resin and epoxy cationic type UV curable resins. Three different in situ monitoring techniques including photocalorimetry(DPA)、rheometer (Physica) and real time FT-IR(RT-IR) were used in order to investigate the kinetics of the photopolymerization process. The free radical type photopolymerization mixtures of trimethylolpropane triacrylate (TMPTA) which has three acrylic groups was added with cleavage photoinitiator HMPP, and the cationic type photopolymerization mixtures of 3,4-Epoxycyclohexylmethyl-3,4-cyclohexanecarboxylate(CELLOXIDE 2021P) that was added with Lewis acid photoinitiator UVI 6976. After that, we prepare different concentrations respectively then formed cross-linking network structures by irradiated ultraviolet beam. During the curing process, Photo-DSC which is also called DPA (Double Beam Photocalorimetric Accessory) was used to detect the endothermic or exothermic reaction heats, then converting to calorimetric conversions and were used for Kamal’s model；Real-time FTIR was used to investigate the evolution about the ratio of characteristics peak to standard peak by adding ultraviolet beam, then converting to conversions and were also used for Kamal’s model to test and verify the UV-curing’s data under static behavior with DPA. On the other hand, rheometer was used to get rheological conversions that were calculated from storage modulus (G’) during curing processes, the values are used for Malkin and Kulichikhin’s model to indicate the data about kinetic behavior UV-curing. Free radical and cationic UV curable systems in the static measurement(DPA、RTIR) were both observed to have critical values for the amounts of photoinitiator in isothermal environment；In the kinetic measurement (Physica), we found that Free radical type also have an extreme values and existed ”Trommsdorff effect”. However, the G’∞ of cationic photopolymerization was affected due to chain growth mechanism interfered with dynamic shear strain on intermediate of decomposed photoinitiator.