非均相体系高取代度羟乙基纤维素的制备及表征

Preparation and characterization of hydroxyethyl cellulose with high degree of substitution in heterogeneous system

在500 L反应釜中,以精制棉为原料,在500 L反应釜中,以87.7%异丙醇-水为溶剂,采用一步碱化分步中和分步醚化工艺制备羟乙基纤维素（HEC）。通过色谱法测定所制备HEC的摩尔取代度MS。以纤维素质量为1,运用正交实验设计对碱量、溶剂量、醚化剂加入量进行优化,得到制备高取代度HEC最佳工艺条件为：碱量为0.3,溶剂量为9,环氧乙烷量为1.0。经红外和13C质谱法对所得HEC进行定性分析,并与商品级Dows 250型HEC产品进行对比。结果表明,制备出的产品为羟乙基纤维素,取代度MS为2.2~2.9,达到与取代度为2.2~2.4的商品级Dows 250型HEC产品相同的质量标准。将该HEC用于乳胶漆的制作,对乳胶漆的成膜性、流平性均有改善作用。

Hydroxyethyl cellulose（ HEC） is prepared in isopropanol-water heterogeneous system through an alkalization / fractional neutralization / fractional etherification process by using refined cotton as raw material. The molar degree of substitution（ MS） of HEC is tested by chromatography. The optimization of reaction conditions for preparation of HEC is conducted by using orthogonal experimental method taking the weight of cellulose as 1. The MS of HEC can reach as high as 2. 2 to 2. 9 under the following conditions： 0. 3 of alkali,9 of solvent volume,1 of epoxy ethane volume,which is comparable with the commercial product 250 HEC products from Dows. When HEC is used in the production of latex paint,both latex film formation and leveling effects are improved.