DSC法研究苯基异氰酸酯与木素、纤维素、木粉的反应特性  

DSC Characterization of the Reactions of Phenyl Isocyanate with Lignin, Cellulose and Wood Powder

作　　者：顾继友[1] 耿志忠[1] 高振华[1] 

机构地区：[1]东北林业大学材料科学与工程学院,哈尔滨150040

出　　处：《林业科学》2007年第9期57-62,共6页Scientia Silvae Sinicae

基　　金：教育部博士点基金(20050225011)

摘　　要：用差式扫描量热法(DSC)对苯基异氰酸酯与木素、纤维素、木粉的反应进行探究。在不同升温速率下,试验对比苯基异氰酸酯分别与木素、木粉在绝干含水率和平衡含水率(木素为3%,木粉为5%)条件下的反应特征;同时研究木素存在下苯基异氰酸酯与纤维素的反应特性。基于对DSC图的讨论分析和Ozawa方程,求解苯基异氰酸酯分别与木素、木粉反应的活化能,初步揭示异氰酸酯分别与木素、纤维素、木材的胶接反应特性。研究表明:苯基异氰酸酯与木素反应温度和活化能相对于苯基异氰酸酯与木粉反应的温度和活化能要低;木素与纤维素混合时,异氰酸酯主要与木素反应,当纤维素的含量较大时,纤维素与异氰酸酯反应程度加大;当木材含水率为5%时,水分导致含水木材与异氰酸酯反应活化能降低了34%。The bonding reactions of isocyanate resin to wood are composed of those that isocyanate group reacted with lignin, semicellulose, cellulose and water. As a result, the knowledge about reaction of isocyanate group with each wood component does well to understand and to control wood bonding with isocyanate resin. Therfore, the paper mainly studied on the reactions between the phenyl isocyanate （BMI） and lignin, cellulose, wood powder by the differential scanning calorimetry （DSC） technique. In different calefactive rates, it characterized the reactions of isocyanate with lignin, wood powder, respectively, with two moisture contents（MC） which were absolute dry moisture content（ MC = 0% ） and equilibrium moisture content （MC = 3% for lignin, and 5 % for wood powder） . It also evaluated the reactions characterizations of isocyanate with the mixtures of lignin and cellulose with different weight ratios. Based on the analyses to the DSC curves and Ozawa equation, the activation energies of the reactions of the BMI-lignin, BMI-wood powder were obtained, by which the reaction characterizations of the phenyl isocyanate with lignin, cellulose, and wood powder are discussed. The study indicated that the reaction temperature and activated energy of BMI-lignin system were lower than those of BMI-wood system. The BMI mainly reacts with lignin when cellulose and lignin were mixed together. However, the reaction degree of BMI with cellulose increased with the cellulose content increasing in cellulose-lignin mixture. When the moisture content of wood reached 5 %, the reaction activation of BMI-wood system reduced 34%.

关 键 词：异氰酸酯 木素 纤维素 木材 差式扫描量热法 

分 类 号：S781.65[农业科学—木材科学与技术]