多元醇液化柳杉為基質PU樹脂之薄膜性質及填縫膠合性能

Properties of Films and Performances of Gap-filling Adhesion of Polyurethane Resins Made from Polyhydric Alcohol Liquefied Cryptomeria Japonica

本研究將多元醇液化柳杉與Desmodur L及Desmodur N兩種異氰酸酯在不同NCO／（OH＋COOH）官能基莫耳比條件下混合調配聚胺基甲酸酯樹脂（Polyurethane resins；PU resins），分析其所製作PU樹脂薄膜之物理、機械性質及熱性質，並探討此PU樹脂應用於木材填縫膠合之可行性。由試驗結果得知，以Desmodur N為原料者之薄膜有較佳耐溶劑性及較大的拉伸變形量，以Desmodur L為原料者則有較大之彈性係數。DSC分析顯示常溫硬化之PU樹脂在熱掃描過程均出現放熱現象，其中以Desmodur L為原料者放熱現象較明顯，其放熱峰高度及溫度範圍均較大；TGA分析顯示以Desmodur N為原料者有較佳之耐熱性，其熱裂解重量損失主要發生在300-400℃，而以Desmodur L為原料者則發生在200-350℃，然不同NCO／（OH＋COOH）莫耳比PU樹脂均呈現相似之熱裂解現象。將PU樹脂應用於填縫膠合時，以Desmodur L為原料且採用NCO／（OH＋COOH）莫耳比1.5者具有最佳之溫水浸水及反覆煮沸浸水膠合強度。 In this study, polyhydric alcohol liquefied Cryptomeria japonica was blended with different isocyanate (i.e. Desmodur L and Desmodur N) with various NCO/(OH+COOH) molar ratios to prepare polyurethane resins. The physical, mechanical and thermal properties of PU films were analyzed and the feasibility of gap-filling adhesion of these PU resins was also investigated. The results show that films made with Desmodur N had the better solvent-resistance and had a larger tensile deformation. However, films that using Desmodur L as the raw material a higher elastic modulus. DSC analysis shows that room temperature cured PU resins appeared an exothermic phenomenon during the period of heat-scanning. While, using Desmodur L as the raw material had an exothermic peak with larger height and broader temperature range. TGA analysis shows that using Desmodur N as the raw material had a better heat-resistance; their weight loss due to thermo-degradation mainly occurred at 300-400℃, but it occurred at 200-350℃ for those using Desmodur L as the raw material. However, the PU resins with various molar ratios of NCO/ (OH+COOH) had similar thermal degradation behavior. When PU resins were used for gap-filling adhesion, using Desmodur L as the raw material with the NCO/ (OH+COOH) molar ratio of 1.5 had the best bonding strength after warm water and repetitive boiling water soaked.

In this study, polyhydric alcohol liquefied Cryptomeria japonica was blended with different isocyanate (i.e. Desmodur L and Desmodur N) with various NCO/(OH+COOH) molar ratios to prepare polyurethane resins. The physical, mechanical and thermal properties of PU films were analyzed and the feasibility of gap-filling adhesion of these PU resins was also investigated. The results show that films made with Desmodur N had the better solvent-resistance and had a larger tensile deformation. However, films that using Desmodur L as the raw material a higher elastic modulus. DSC analysis shows that room temperature cured PU resins appeared an exothermic phenomenon during the period of heat-scanning. While, using Desmodur L as the raw material had an exothermic peak with larger height and broader temperature range. TGA analysis shows that using Desmodur N as the raw material had a better heat-resistance; their weight loss due to thermo-degradation mainly occurred at 300-400℃, but it occurred at 200-350℃ for those using Desmodur L as the raw material. However, the PU resins with various molar ratios of NCO/ (OH+COOH) had similar thermal degradation behavior. When PU resins were used for gap-filling adhesion, using Desmodur L as the raw material with the NCO/ (OH+COOH) molar ratio of 1.5 had the best bonding strength after warm water and repetitive boiling water soaked.