摘要
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25g/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2.62meq/g和113%.共聚反应后其分子量由木聚糖的21 640g/mol增加为112 350g/mol.木聚糖-METAC共聚物的水溶液符合假塑性流体特征.
Xylan is a part of hemicelluloses of woody materials and can be converted to value- added 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 ttme,75 C reaction temperature,pH 7 and 25 g/L xylan concentration. The copolymer was characterized by charge density analyzer, viscometer, gel permeation chroma-tography （GPC） , hydrodynamic diameter analyzer, fourier transform infrared spectroscopy （FTIR） and elemental analyzer. The results showed that the charge density and 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.
出处
《陕西科技大学学报》
CAS
2017年第3期1-7,13,共8页
Journal of Shaanxi University of Science & Technology
基金
国家自然科学基金项目(31570566
31500489
31170547)
山东省自然科学基金项目(ZR2011CM011
ZR2013CQ020)
