酚／雙酚A液化柳杉製備環氧化Novolac型酚醛樹脂之性質

Property of Epoxidized Novolac Phenol-Formaldehyde Resin Prepared from Phenol/Bisphenol A Liquefied Cryptomeria Japonica

朱建芳(Chien-Fang Chu) ； 李文昭(Wen-Jau Lee)

《林產工業》 38卷1期 (2019/03) Pp. 31-42

https://doi.org/10.6561/FPI.201903_38(1).0003

摘要

本研究將柳杉木粉以酚／雙酚A為溶劑進行液化處理，並利用酚及液化木材（Liquefied wood; LW）為原料合成PF及LW-PF兩種Novolac型酚醛樹脂（Phenol-formaldehyde resin; PF），再將重量比100／0、70／30及50／50之PF／LW-PF混合樹脂與環氧氯丙烷反應製備EPF-100、EPF-73、EPF-55三種環氧化PF樹脂（Epoxidized PF resin; EPF）。由結果得知，PF樹脂之OH基可與環氧氯丙烷反應而導入環氧基。添加三乙基四胺（Triethylene tetramine; TETA）、六亞甲基四胺（Hexamethylenetetramine; Hexamine）及Hexamine／TETA之EPF樹脂在熱示差掃描卡量（Differential scanning calorimetry; DSC）分析過程皆出現架橋反應之放熱峰。採用Hexamine／TETA為架橋硬化劑之EPF樹脂有較大的溶出試驗重量保留率。熱重分析（Thermogravimetry analysis; TGA）結果顯示硬化EPF樹脂之熱裂解包含兩個階段，其中藉由亞甲基形成之架橋結構的熱抵抗性大於透過環氧基所形成之架橋連結。不同EPF樹脂比較，以EPF-73所製作成型板有較高的彎曲強度及較佳的熱抵抗性。

關鍵字

柳杉 ； 架橋硬化劑 ； 環氧化酚醛樹脂 ； 液化木材 ； 成型板

並列摘要

In this study, wood powders of Cryptomeria japonica (Japanese cedar) were liquefied in the mixture of phenol and bisphenol A. The novolac-type phenol-formaldehyde resins, PF and LW-PF, were synthesized by using phenol and liquefied wood as raw materials, respectively. Epoxidized PF resins (EPF), named EPF-100, EPF-73, and EPF-55 were prepared by reacting the mixture of PF and LW-PF that had the weight ratio of 100/0, 70/30, and 50/50 with epichlorohydrin, respectively. The results showed that epoxy groups could be introduced into PF resins by reacting PF resin with epichlorohydrin. The exothermic peak that caused by the crosslinking reaction had been found in differential scanning calorimetry (DSC) analysis when the EPF resin was mixed with triethylene tetramine (TETA), hexamethylenetetramine (hexamine), or a mixture of hexamine and TETA as a crosslinking hardener. EPF resin that cured with hexamine/TETA had larger weight retention after dissolution test. Thermogravimetric analysis (TGA) showed a two-stage thermo-degradation of cured EPF resins. The crosslinked structure built with methylene bridging had better heat resistance than that formed by epoxy group. Comparison between different EPF resins, molding plate made with EPF-73 had higher bending strength and better heat resistance than others.

並列關鍵字

Cryptomeria japonica ； Crosslinking hardener ； Epoxidized phenol-formaldehyde resin ； Liquefied wood ； Molding plate