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標題: Properties of Novolac-Type Phenol-Formaldehyde Resins Prepared from “Cryptomeria japonica” Liquefied with Phenol/Bisphenol A
作者: 朱建芳
Chien-Fang Chu
Wen-Jau Lee
關鍵字: Cryptomeria japonica;Liquefied wood;Molding plates;Novolac-type phenol-formaldehyde resins;柳杉;液化木材;成型板;Novolac型酚醛樹脂
Project: 林業研究季刊, Volume 37, Issue2, Page(s) 133-142.
本研究將柳杉木粉以酚及重量比6/4之酚/雙酚A混合液為液化藥劑,H_2SO_4為催化劑,以150oC加熱60 min進行液化處理,分別獲得PLW及BLW兩種液化柳杉,再將PLW、BLW及化石酚與甲醛於酸性環境下反應製備PF、PLW-PF及BLW-PF三種novolac型PF樹脂。由試驗結果顯示,木材組成分可與液化藥劑結合形成衍生物,其中PLW有較低之平均分子量及分子量分散度。三種novolac型PF樹脂均具備熱熔融特性,其中PF樹脂之熔點及平均分子量較低。未添加硬化劑之novolac型PF樹脂在DSC熱掃描過程出現吸熱現象,添加六亞甲基四胺則出現架橋反應之明顯放熱峰,其中以PF樹脂之熱活動現象及熱架橋反應較PLW-PF樹脂及BLW-PF樹脂明顯。將重量比100/0、70/30、50/50之PF/BLW-PF樹脂混合麻六甲合歡木粉、六亞甲基四胺所製作成型板具備優良之尺寸安定性。然成型板之內聚強度及抗彎強度隨BLW-PF所占比例增加而降低。

In this study, wood powders of "Cryptomeria japonica" (Japanese cedar) were liquefied in phenol and the mixture of phenol/bisphenol A (6/4, wt/wt) with H2SO4 as a catalyst at 150oC for 60 min to obtain the liquefied wood of PLW and BLW, respectively. The fossil phenol, PLW and BLW were reacted with formaldehyde under acid condition to prepare three kinds of novolac resins, named PF, PLW-PF and BLW-PF. The results show that wood components could combine with liquefaction reagents to form derivatives. The PLW had lower average molecular weight and molecular weight dispersity than the BLW. All of these three novalac-type PF resins had the behavior of hot-melting. Among them, PF resin had lower melting point and less average molecular weight than others. Novalac-type PF resins without hardener showed an endothermic phenomenon during DSC heat scanning. However, an obvious exothermic peak due to crosslinking reaction appeared when hexamethylene tetramine was added. The phenomenon of thermal activity and thermal crosslinking were more obvious for PF resin than PLW-PF and BLW-PF. Molding plates made with the mixture of PF/BLW-PF resins that had the weight ratio of 100/0, 70/30 and 50/50, "Albizzia falcate" wood flour and hexamethylene tetramine had good dimensional stability. However, the internal bonding strength and bending strength of molding plates decreased with increasing the weight ratio of BLW-PF.
Appears in Collections:第37卷 第02期

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