多元醇液化柳杉製備聚胺基甲酸酯樹脂塗料

Polyurethane Coatings Prepared from Polyhydric Alcohol Liquefied Cryptomeria japonica

本研究將柳杉（Cryptomeria japonica；Japanese cedar）木材以聚乙二醇－丙三醇（PEG-Glycerol）混合液為溶劑，H2SO4為催化劑進行液化處理，進一步將其液化木材與與異氦酸醋DesmodurL混合調配成聚肢基甲酸醋樹脂（Polyurethane resin；PU），探討此PU樹脂之乾燥性、乾燥薄膜機械性質、熱性質，及其塗裝材之塗膜性質。由試驗結果得知，在氮氣環境下進行液化處理對降低液化木材之顏色並無改善效果，然其液化產物之殘渣率及粘度明顯較低：液化木材與Dosmodur L混合所調配之PU樹脂具備常溫乾燥硬化性，隨NCO／（OH+COOH）官能基莫耳比增加，其薄膜之拉伸破壞強度提高，破壞伸長率則減少，熱活動性降低，加熱可促進常溫硬化之樹脂進行其後硬化反應；此PU樹脂塗裝材之塗膜硬度隨NCO／（OH+COOH）莫耳比提高而增加，抗彎曲性則降低，其塗膜具良好之耐候性、耐酸性及耐鹼性。 The wood of Cryptomeria japonica (Japanese cedar) was liquefied in polyethylene glycol-glycerol co-solvent with H2SO4 as the catalyst. The liquefied product was mixing with Desmodur L, one of the isocyanate compounds, to prepare polyurethane (PU) resins. The drying property of these PU resins and the mechanical and thermal properties of their dried films were investigated. In addition, the feasibility of using these PU resins as coatings was also investigated. The results showed that wood liquefied under nitrogen atmosphere had no effect to reduce the color of liquefied wood. However, their products had lower un-liquefied residue and lower viscosity. The PU resins those prepared by blending liquefied wood with Desmodur L could dry under room temperature. When the molar ratio of NCO/(OH+COOH) of PU resins increased, the tensile strength of films increased, the elongation at breaking decreased, and the thermal activity lowered. Heat treatment could promote the post-curing of room temperature cured PU resins. Increasing the molar ratio of NCO/(OH+COOH) could increase the hardness of coating films, but decrease the bending resistance. All the PU coating films had a good weather resistance, acid resistance, and alkali resistance.

The wood of Cryptomeria japonica (Japanese cedar) was liquefied in polyethylene glycol-glycerol co-solvent with H2SO4 as the catalyst. The liquefied product was mixing with Desmodur L, one of the isocyanate compounds, to prepare polyurethane (PU) resins. The drying property of these PU resins and the mechanical and thermal properties of their dried films were investigated. In addition, the feasibility of using these PU resins as coatings was also investigated. The results showed that wood liquefied under nitrogen atmosphere had no effect to reduce the color of liquefied wood. However, their products had lower un-liquefied residue and lower viscosity. The PU resins those prepared by blending liquefied wood with Desmodur L could dry under room temperature. When the molar ratio of NCO/(OH+COOH) of PU resins increased, the tensile strength of films increased, the elongation at breaking decreased, and the thermal activity lowered. Heat treatment could promote the post-curing of room temperature cured PU resins. Increasing the molar ratio of NCO/(OH+COOH) could increase the hardness of coating films, but decrease the bending resistance. All the PU coating films had a good weather resistance, acid resistance, and alkali resistance.