金属盐催化剂对气体甲醛与纤维素及其模型化合物反应的影响

Effect of Catalyst on the Cross-linking of Formaldehyde Vapor with Cellulose Model Compounds

本文研究了在无机金属盐催化剂作用下 ,气体甲醛与棉纤维、微晶纤维素、纤维二糖和木聚糖的反应。结果表明 :催化剂的种类、浓度、反应时间以及纤维素模型化合物的分子体积、空间位阻等对反应都有重要影响。相同条件下 ,气体甲醛与微晶纤维素的反应性高于棉纤维 ,而纤维素的模型化合物纤维二糖与气体甲醛可发生交联反应 ,生成多聚糖。

The reaction of cotton fiber and other polysaccharides with formaldehyde vapor under the catalysis of inorganic salts was studied It was found that the catalysts kind, concentration and reaction time played an important role in the vapor phase formylation The results indicated that ZnCl 2 was the most efficient catalysis among the salts ZnCl 2, Zr(SO 4) 2 and Al 2(SO 4) 3 There existed an optimum concentration when ZnCl 2 was employed, i e , the highest weight percent gain ( WPG ) was obtained at a catalyst content of 8 2×10 5 Meanwhile, extending the reaction duration was helpful to increase WPG Fourier transform infrared spectrometry (FT IR) and high performance liquid chromatography (HPLC) analyses illustrated that cross linking reaction happened between formaldehyde and fiber WPG was less when compared cotton fiber with other cellulose model compounds, which suggested the cross linking was related with steric effect and finite zone HPLC spectrum of cellobiose proved digestible polysaccharide formation