- 期刊
PEG／Glycerol液化杉木製備PU樹脂之性質及其在膠合劑之應用
Properties of PU Resins Prepared from PEG/Glycerol Liquefied China Fir and Its Utilization as Adhesives
摘要
本研究以分子量200、400、600、1000之聚乙二醇（PEG）與丙三醇（Glycerol）之混合液為溶劑，以硫酸（H_2SO_4）為催化劑，對杉木（Cunninghamia lanceolata; China fir）木材進行液化處理，並將不同條件液化杉木與異氰酸酯Desmodur L在NCO／（OH+COOH）莫耳比1.5 及2.0之條件下混合調配PU樹脂，探討其PU樹脂之薄膜性質及膠合性。由結果得知，液化時以PEG-400／Glycerol組成比90／10為溶劑，硫酸添加量3%者有較佳之液化效果。液化杉木與Desmodur L混合所調配之PU樹脂具備常溫硬化性，且膠化度在87.4%以上。PU樹脂調配時NCO／（COOH＋OH）莫耳比為2.0者所得薄膜有較高之拉伸強度及彈性係數，不同條件液化木材比較以PEG分子量400，PEG／Glycerol組成比90／10，酸催化劑添加量3%之C-400-1最佳。液化杉木為基質之PU樹脂具備良好之常態膠合強度，其常態之最大膠合強度值達106 kgf／cm^2，而耐溫水之膠合強度值均可達CNS 11031 號標準中所要求之60 kgf／cm^2以上，耐煮沸反覆浸水之膠合強度則以液化時以PEG-400／Glycerol為90／10，酸催化劑添加量6%，並採用NCO／（OH+COOH）莫耳比2.0之PU樹脂為最佳。
並列摘要
In this study, China fir (Cunninghamia lanceolata) was liquefied by using polyethlyene glycol (PEG) and glycerol co-solvent with H2SO4 as catalyst. The PEG used had various molecular weights, i.e. PEG-200, 400, 600 and 1000. The various liquefied woods were blended with isocyanate (Desmodur L) under the molar ratio of NCO/(OH+COOH) of 1.5 and 2.0 to prepare the PU resins. The properties of the PU films and the adhesion capability of PU resins were investigated. The results showed that China fir liquefied with PEG-400/glycerol co-solvent under the weight ratio of 90/10 and 3% of H2SO4 had the best liquefaction effect. The PU resins prepared from the blending of liquefied China fir with Desmodur L could cure at room temperature and their gel contents were over 87.4%. The films made from PU resins which were prepared with the NCO/(OH+COOH) molar ratio of 2.0 had the higher tensile strength and modulus of elasticity. Comparing among the liquefaction conditions, the liquefied wood of C-400-1 which was liquefied by using PEG-400 with PEG/glycerol ratio of 90/10 and the addition of 3% H_2SO_4 was the best. All the PU resins with liquefied China fir as the base material had good dry and warm water soaked bonding strength, its maximum dry bonding strength could achieve 106 kgf/cm^2 and the warm water soaked bonding strength could meet the standard of CNS 11031 which requires the strength over 60 kgf/cm^2. The PU resin prepared from the liquefied wood that was liquefied with 90/10 of PEG-400/glycerol and 6% of H2SO4, and blending with Desmolur L at the NCO/(OH+COOH) molar ratio of 2.0 had the best cyclic boiling water soaked bonding strength.