To determine optimum catalyst concentration, phenol-Eucalyptus bark ratio, liquefaction temperature, and liquefaction time on bark liquefaction, as well as factors influencing resinifieation; phenol in the presence of 36％ (360 g·L-1) suffuric acid was used to liquefy Eucalyptus bark and analyzed using an orthogonal design with a single factor analysis. Results showed that (1) effects on Eucalyptus bark liquefaction, from greatest to least, were: liquid ratio ＞ liquefaction temperature ＞ liquefaction time. (2) The orthogonal experiment revealed optimum liquefaction processing parameters of: phenol-Eucalyptus bark ratio of 10: 3, reactive temperature of 150° C, reactive time of 80 min, and a 36％(360 g·L-1) sulfuric acid content of 6％ for the total liquefaction. (3) To prepare resin and press plywood panels using liquefied bark as a standard, the following was selected: formaldehyde molar ratio of 1.6, NaOH molar ratio of 0.3, water molar ratio of 8.0,and a reaction temperature of 95° C. Thus, Guangxi Zhuang Autonomous Region Product Quality Supervision and Inspection Centre detected a product moisture content of 10％ which was within technical requirements,an average bonding strength of 0.835 8 MPa which met the technical requirements of Type 1 Plywood, and formaldehyde emission of 1.5 mg·L-1 which qualified for classification at E2 levels.%在质量浓度为36%(360g·L-1)的硫酸催化作用下用苯酚对桉树Eucalyptus spp.树皮进行液化,考察催化剂用量、液固比、液化温度和液化时间对液化反应效率的影响;通过正交实验得到桉树树皮液化的较佳方案,并对桉树树皮液化物树脂化的影响因素进行研究.结果表明:①液固比对桉树树皮液化效果的影响最大,其次依次为液化温度、液化时间.②通过单因素分析法和正交试验法相结合,得出桉树树皮较理想的液化工艺条件:液固比为10:3,液化温度为150℃,液化时间为80min,质量浓度36%硫酸用量为液化物总量的6%.③以树皮液化物为基准,选择甲醛摩尔比为1.6,氢氧化钠摩尔比为0.3,水摩尔比为8.0,缩聚温度95℃的树脂化工艺制备树脂胶黏剂用于压板.样板经过广西壮族自治区产品质量监督检验院的检测:产品的含水率为10%,在技术要求范围内;胶合强度的平均值为0.835 8 Mpa,在Ⅰ类胶合板的技术要求内;甲醛释放量为1.5 mg·L-1,属于E2级别.
展开▼
