纤维素月桂酸酯的制备及其结构和性能表征

Preparation of cellulose laurate and characterization of its structure and performance

在均相体系下,以微晶纤维素为原料,以月桂酰氯为酯化试剂,吡啶为催化脱酸剂制备纤维素月桂酸酯,研究了酯化试剂用量、反应温度、反应时间对纤维素月桂酸酯取代度和得率的影响,确定了合成纤维素月桂酸酯的适宜条件为:酰氯用量1.6 mol(基于纤维素上羟基摩尔数),反应温度100℃,反应时间10 h,此时纤维素月桂酸酯的得率为310.8%,取代度达2.48。采用红外光谱和核磁共振氢谱对纤维素月桂酸酯的结构进行了表征,证明了纤维素已发生酯化反应。接触角实验结果表明,所得纤维素月桂酸酯的接触角随取代度增加而增加,取代度>1.6时产物具有极强的疏水性。

Cellulose laurate was prepared using microcrystalline cellulose as the raw material and lauroyl chloride and pyridine as catalyst under homogeneous reaction conditions.Effects of dosage of lauroyl chloride,reaction temperature,and reaction time on yield and the degree of substitution（DS） of cellulose were investigated.The optimal preparation conditions of cellulose laurate were as follows： dosage of lauroyl chloride 1.6 mol（based on molar of—OH）,reaction temperature 100 ℃,reaction time 10 h,the DS and yield of cellulose laurate was reached 2.48 and 310.8 % respectively.The results of FTIR and 1H-NMR indicated that the esterification had indeed occurred.Dynamic contact angle measurements of cellulose ester revealed that contact angle increased with increasing the DS and better hydrophobic property could be achieved on the condition of DS1.6.