酚液化孟宗竹材製備Novolak型酚樹脂及其在成型物製作之應用

Preparation of Novolak Type PF Resins from Liquefied Moso Bamboo (Phyllostachys pubesens) and Utilization in the Manufacturing of Moldings

本研究以酚為溶劑，硫酸及鹽酸為催化劑對孟宗竹進行液化處理，探討酚液化竹材應用於Novolak型酚樹脂製備之合成條件，並進一步將所得合成樹脂應用於成型材製造。由試驗結果得知，酚液化竹材與甲醛反應性高，以一般Novolak型酚樹脂之合成法易於反應過程發生膠化現象而不適用，採用間苯二酚甲醛樹脂之合成法則可有效降低其反應性，並獲得液體態合成樹脂。於液體態Novolak型酚樹脂中添加四氮六甲基圜、竹粉及硬脂酸鋅所得之成型材原料以DSC分析顯示其具備熱硬化性，熱壓所得成型物經丙酮溶出試驗顯示具有高的膠化度，然浸水時之吸水率較一般Novolak型酚樹脂為原料所製造者為高，其成型物之吸水率與樹脂合成條件及熱壓溫度並無明顯關係，然其中以硫酸為催化劑之液化竹材在甲醛與酚之莫耳比為0.8／1.0所合成之R-S2樹脂為原料，並以溫度180℃熱壓成型者吸水率最低。 In this study, moso bamboo (phyllostachys pubesens) was liquefied in phenol with theH2SO4 and HCl as catalyst. The appropriate synthesis conditions of novolak type PF resins preparedfrom the liquefied bamboo was investigated. The results showed that the synthesis method used fortraditional novolak PF resins would be not suitable. The reactivity of liquefied bamboo was too high and the reactant would cure at the period of synthesis process. But using the method as resorcinolformaldehyde (RF) resin prepared, the reactivity could be deceased effectively and the liquid stateresins obtained. DSC thermal analysis shown the liquid novolak resins mixed with hexamine, bamboopowder, and zinc stearate had the capability of thermosetting. The acetone solubility test shown themoldings made from these novolak resins had the high degree of gel. But the water absorption rateafter soaked in water was higher than that of normal novolak PF resins. There was no significantrelationship between the water absorption and hot-pressing temperature. But the moldings using RS2that prepared from the liquefied bamboo with H2SO4 as a catalyst and had the molar ratio offormaldehyde with phenol as 0.8/1.0, as the raw material and hot-pressed with the temperature of180℃ had the lowest water absorption.

In this study, moso bamboo (phyllostachys pubesens) was liquefied in phenol with theH2SO4 and HCl as catalyst. The appropriate synthesis conditions of novolak type PF resins preparedfrom the liquefied bamboo was investigated. The results showed that the synthesis method used fortraditional novolak PF resins would be not suitable. The reactivity of liquefied bamboo was too high and the reactant would cure at the period of synthesis process. But using the method as resorcinolformaldehyde (RF) resin prepared, the reactivity could be deceased effectively and the liquid stateresins obtained. DSC thermal analysis shown the liquid novolak resins mixed with hexamine, bamboopowder, and zinc stearate had the capability of thermosetting. The acetone solubility test shown themoldings made from these novolak resins had the high degree of gel. But the water absorption rateafter soaked in water was higher than that of normal novolak PF resins. There was no significantrelationship between the water absorption and hot-pressing temperature. But the moldings using RS2that prepared from the liquefied bamboo with H2SO4 as a catalyst and had the molar ratio offormaldehyde with phenol as 0.8/1.0, as the raw material and hot-pressed with the temperature of180℃ had the lowest water absorption.