以酚液化相思樹為基質Novolak型酚甲醛樹脂含浸木粉製造成型板性質之研究

Study on the Properties of Moldings Made with Wood Powders Impregnated with Phenol-liquefied Acacia Confusa Based-novolak Phenol-Formaldehyde Resins

本研究將相思樹木材以酚為溶劑，H2SO4及HCl為催化劑進行液化處理，所得酚液化相思樹與福馬林在甲醇溶液中進行反應製備S-PF及H-PF兩種Novolak型酚甲醛（PF）樹脂溶液，並將其含浸至麻六甲合歡木粉形成樹脂含浸木粉。由DSC熱分析顯示含浸至木粉之乾燥樹脂具熱熔融性，混合六甲基四胺為架橋劑則具備熱硬化性。兩種樹脂含浸木粉混合六甲基四胺後可熱壓製造成型板，其中以H-PF樹脂含浸木粉所製造者其內聚強度及浸水尺寸安定性優於以S-PF樹脂含浸者，在200℃熱壓溫度下，熱壓時間10min者優於熱壓時間12min者；TGA熱分析顯示在相同熱壓溫度下，兩種樹脂含浸木粉所製作成型板具有相似之熱裂解行為，然熱壓時間12min者之耐熱性則優於熱壓時間10min者。 Wood of Acacia confusa Merr. (Taiwan acacia) was liquefied in phenol with H2SO4 and HCl as catalysts. Two kinds of solution-type novolak phenol-formaldehyde (PF) resin, S-PF and HPF, were synthesized by reacting liquefied Taiwan acacia with formalin in methanol. After then, Albizzia falcate wood powders were immersed in these resins to form resin impregnated wood powders. DSC analysis showed that the dried resin that impregnated in wood powders had the behavior of thermo-melting, and had the capability of thermo-setting when mixing with hexamethylenetetramine (hexamine). Both of these PF resin impregnated wood powders could be used to make moldings by hot-pressing when they were mixed with hexamine. Among which, moldings made with H-PF resin impregnated wood powders had better internal bonding strength and dimensional stability than those with S-PF resin impregnated wood powders. When hot-pressed under 200℃, moldings made with the hot-pressing time of 10 min had better properties than those of 12 min. TGA analysis showed that moldings made with H-PF and S-PF resins impregnated wood powders had a similar thermo-degradation behavior for those hot-pressed with the same temperature. However, made with hot-pressing time of 12 min had better thermal resistance than those with 10 min.

Wood of Acacia confusa Merr. (Taiwan acacia) was liquefied in phenol with H2SO4 and HCl as catalysts. Two kinds of solution-type novolak phenol-formaldehyde (PF) resin, S-PF and HPF, were synthesized by reacting liquefied Taiwan acacia with formalin in methanol. After then, Albizzia falcate wood powders were immersed in these resins to form resin impregnated wood powders. DSC analysis showed that the dried resin that impregnated in wood powders had the behavior of thermo-melting, and had the capability of thermo-setting when mixing with hexamethylenetetramine (hexamine). Both of these PF resin impregnated wood powders could be used to make moldings by hot-pressing when they were mixed with hexamine. Among which, moldings made with H-PF resin impregnated wood powders had better internal bonding strength and dimensional stability than those with S-PF resin impregnated wood powders. When hot-pressed under 200℃, moldings made with the hot-pressing time of 10 min had better properties than those of 12 min. TGA analysis showed that moldings made with H-PF and S-PF resins impregnated wood powders had a similar thermo-degradation behavior for those hot-pressed with the same temperature. However, made with hot-pressing time of 12 min had better thermal resistance than those with 10 min.