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为开发环境友好型木材胶黏剂,利用差示扫描量热法(DSC)和流变仪分析了葡甘聚糖、壳聚糖、聚乙烯醇共混胶黏剂的热固化过程和流变特性。结果表明:三元共混胶黏剂的流变特性呈明显的非线性,黏度与剪切速率的关系可用Cross模型拟合,黏度与温度的关系可用Arrhenius方程拟合,前置因子K为1.25×10-6Pa.s,流动活化能为54.24 kJ/mol,频率曲线可用四阶多项式拟合,同时可得到胶黏剂的平均分子量随温度升高逐渐降低,分子量分布随着温度升高逐渐增大。温度和时间扫描得到凝胶化温度110.4℃,凝胶时间20.1 min,玻璃化转变温度87.4℃,加热温度130℃。
In order to develop environment-friendly wood adhesives, the thermosetting process and rheology of glucomannan, chitosan and PVA blend adhesives were analyzed by differential scanning calorimetry (DSC) and rheometer characteristic. The results show that the rheological properties of the ternary blend adhesives are obviously non-linear. The relationship between viscosity and shear rate can be fitted by Cross model. The relationship between viscosity and temperature can be fitted by Arrhenius equation, and the pre-factor K is 1.25 × 10-6Pa · s, and the activation energy of flow is 54.24 kJ / mol. The frequency curve can be fitted by the fourth-order polynomial. At the same time, the average molecular weight of the adhesive decreases gradually with increasing temperature. The molecular weight distribution gradually increases with increasing temperature Big. Temperature and time scanning gelation temperature 110.4 ℃, gel time 20.1 min, glass transition temperature 87.4 ℃, heating temperature 130 ℃.