Xylan is a part of hemicelluloses of woody materials and can be converted to valueadded products.In this paper,Birch xylan was selected as a model and rendered cationic via copolymerization with [2-(Methacryloyloxy) ethyl] trimethylammonium chloride (METAC).The influences of reaction conditions,including molar ratio of METAC/xylose,temperature,pH,reaction time as well as xylan concentration,on the copolymerization were investigated in details.The optimum conditions were 3 ∶ 1 molar ratio of METAC/xylose,2.5 h reaction time,75 ℃ reaction temperature,pH 7 and 25 g/L xylan concentration.The copolymer was characterized by charge density analyzer,viscometer,gel permeation chromatography (GPC),hydrodynamic diameter analyzer,fourier transform infrared spectroscopy (FTIR) and elemental analyzer.The results showed that the charge density and grafting ratio of xylan-METAC copolymer prepared at optimum conditions could reach to 2.62 meq/g and 113 ％ respectively.The molecular weight was increased from original 21 640 g/mol to 112 350 g/mol.The solution of xylan-METAC copolymer had pseudoplastic behavior.%木聚糖是半纤维主要的聚糖之一,通过改性可以转变为高附加值的产品.进行了木聚糖和阳离子功能性单体[2-(甲基丙烯酰氧基)乙基]三甲基氯化铵(METAC)在水相中共聚合成木聚糖-METAC共聚物的研究.对共聚反应中的各个因素,包括METAC/木聚糖的摩尔比、反应温度、反应时间、pH以及木聚糖浓度,对最终产物的接枝率和电荷密度的影响进行了探讨.利用傅里叶红外光谱(FTIR)、电荷密度测定仪、元素分析仪、凝胶渗透色谱(GPC)、粘度仪以及水力学粒径分析仪对木聚糖-METAC的结构及特性进行了分析.结果表明,在水相溶液中,采用过硫酸钾为引发剂,可以成功制备出具有阳离子电荷的木聚糖-METAC共聚物.最优合成工艺条件为:3∶1 METAC/木糖摩尔比,2.5h反应时间,75℃,pH 7.0和25 g/L木聚糖浓度.制得的木聚糖-METAC的电荷密度和接枝率分别可以达到2.62 meq/g和113 ％.共聚反应后其分子量由木聚糖的21 640 g/mol增加为112 350 g/mol.木聚糖-METAC共聚物的水溶液符合假塑性流体特征.
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