脂肪族聚胺酯反應動力學之研究及發泡體合成

Abstract

論文中動力學的研究可分為兩部分，一是對於異佛爾酮二異氰酸酯(IPDI)的特性與預聚物反應特性分析(prepolymerization)。二是總體聚合反應下(bulk polymerization)異氰酸鹽與醇的反應，反應產生的是聚胺基甲酸酯(polyurethane)的特性分析與異氰酸鹽與水的反應，反應產生的是聚脲(polyurea)的特性分析，利用傅立葉轉換紅外光儀(FTIR)掃描400~4000cm-1之吸收光譜並紀錄異氰酸鹽基吸收峰（-NCO，2270cm-1）面積變化來代入速率式進行參數推導並分別以催化劑種類與濃度、溫度、反應結構為因素說明影響反應變化，活化能的參數則分別在30~60℃下反應所得的動力學數據推導，而由動力學資料分析發現異佛爾酮二異氰酸酯容易受結構障礙影響，而預聚物反應初、中期遵守二階反應(second order)與文獻所提相同，而後期反應較快，偏離理論反應率，總體聚合下異氰酸鹽的反應則發現伴隨顯著的自加速反應(autoacceleration)並推测其反應加速的原因是因為胺基甲酸酯(urethane)或脲(urea)鍵的氫鍵吸引力活化單體所造成，經由實驗數據與理論速率式驗證，證明反應初期應是由催化劑催化起始反應且遵守二階反應(second order)，而由於胺基甲酸酯(urethane)或脲(urea)鍵濃度隨著反應的增加，開始出現自加速反應且以三階反應(third order)速率式進行，所以重新定義異氰酸鹽反應速率式，並推導胺基甲酸酯(urethane)或脲(urea)鍵加速反應的機構。另外針對發泡的配方，探討了聚醚多元醇單體特性及光安定性及各種鏈延長劑與交聯劑的熱穩定性，並對所有參與發泡反應的成份，催化劑、界面活性劑、水、物理發泡劑、合成方式逐一探討其對泡體性質的影響。

Kinetics of the catalyzed reaction between isophorone diisocyanate(IPDI) and hydroxyl-terminated Polyolpolypropylene glycol(PPG) and polytetramethylene glycol(PTMG) and the reaction between isocyanate-terminated prepolymer (IPDI-PPG2000-IPDI) and water was investigated by using FTIR spectroscopy.Dibutyltin dilaurate(DBTDL) was used as the prepolymeriztion catalyst and various tertiary amines were used for the foaming reaction catalysts ,the reaction was followed by monitoring the change in intensity of the absorption band at 2270 cm-1 for NCO stretching in the FTIR spectrum,and the activation parameters were obtained from the evaluation of kinetic data at different temperatures in the range of 30~60℃.Analysis of the kinetic data indicates that the isocyatate-hydroxyl reaction for prepolymerization was shown to follow a second-order kinetics in the initial stage ,while in bulk polymerization that we find an autoacceleration reaction obviously and reaction was shown to follow a third-order kinetics. Steric structure has a great effect on the isophorone diisocyanate’s reaction .An activation energy of 64.88kJ/mol for the reaction between IPDI and PPG2000 under DBTDL catalyzed and that of 70~90kJ/mol for the reaction between isocyanate-terminated prepolymer and water under tertiary amines catalyzed showed that the influence of the temperature in urea-forming reaction is higher than the urethane-forming reaction.Finally the effects of PPG monomer,catalyst,surfactant,blow agent,chain extender and synthetic process on the properties of flexible polyurethane foam were investigated.