机械活化固相法制备丁二酸蔗渣纤维素酯及性能研究

Study on preparation and property of succinate bagasse cellulose ester by mechanical activation solid phase method

以蔗渣纤维为原料,采用机械活化法合成丁二酸蔗渣纤维素酯。通过扫描电子显微镜、傅里叶变换红外光谱仪、示差扫描量热仪、热重分析仪观察改性前后材料的微观形貌、分子基团、热学性能的变化,通过测定结合酸含量描述反应进行的程度。结果表明:蔗渣纤维在机械活化作用下,细化成细小颗粒,机械力能削弱纤维素分子内或分子间的氢键作用,强化蔗渣纤维与丁二酸酐发生酯化反应;反应后材料的亲水性增强,且更易脱水与解聚;接入的羧基含量随反应时间与催化剂用量的增加先提高后减小,提高温度或增加酯化剂用量有利于反应的进行,当反应时间为2.0h、催化剂用量为4%时,羧基含量高达5.21mmol/g。与传统酯化改性相比,机械活化固相酯化反应条件更加温和,且不需要使用有机溶剂,避免了二次污染。

Succinate bagasse cellulose ester(SABC)was synthesized by mechanical activation(MA)method with bagasse cellulose(BC)as raw material.Scanning electron microscope,fourier transform infrared spectrometer,differential scanning calorimeter and thermogravimetric analyzer were used to observe the changes of micromorphology,molecular groups and thermal properties of the materials before and after modification,and described the degree of reaction by measuring the content of combined acid.Results showed that BC was refined into fine particles under MA,and esterified with SA.Besides,carboxyl group was introduced.The mechanical force could weaken the hydrogen bond within or between the molecules of cellulose and strengthened the reaction.The interaction between the product and the bound water was strengthened,and the side chain connected enhanced the dehydration or depolymerization.When the reaction time or the amount of catalyst was increased,the content of the introduced carboxyl group increased initially and then decreased.While raising temperature or increasing the amount of esterification agent was conducive to the reaction.When the reaction time was 2.0 h and the amount of catalyst was 4%,the content of carboxyl group was as high as 5.21 mmol/g.Compared with traditional esterification method,the MA solid reaction had more mild conditions without using organic solvents,which can avoid the secondary pollution.