基于松木纤维醚化反应的羟乙基纤维素的制备

松木纤维素中α-纤维素含量高达87％，以其为原料，乙醇为溶剂，2-氯乙醇为醚化剂，采用两次加碱两次醚化的方法制备了具有较高摩尔取代度（MS）的羟乙基纤维素（HEC）。并以正交实验评价了各实验因素对 HEC摩尔取代度的影响。结果表明：各因素对 H EC摩尔取代度影响的大小顺序为：醚化剂总量＞碱剂总量＞第一次加醚百分比＞第一次加碱百分比＞90％（体积分数）乙醇的体积。由此得到的制备HEC的较佳工艺为：于80 mL90％（体积分数）乙醇中，第一次加0．5gNaOH于40℃碱化0．5h，升温至65℃，加2．7mL2-氯乙醇醚化1．5h，然后加入0．5gNaOH和0.3 mL 2-氯乙醇再醚化1．5 h。在此条件下得到了MS高达1．657的HEC ，并用FT-IR、XRD和NMR对其进行了表征。

Preparation of Hydroxyethyl Cellulose Based on Etherification Reaction of Pine Fiber

α-cellulose content in pine cellulose is as high as 87% .hydroxyethyl cellulose （HEC） with high molar substitution degree is prepared through using α-cellulose as the raw material ,ethanol as the solvent and 2-chloroethanol as the etherifying agent and adopting the method of twice adding alkali and twice etherifying .The effects of the experimental factors on molar substitution degree of HEC are evalua-ted with orthogonal experiment .The results show that the order of the effects of each factor on molar sub-stitution degree of HEC was as follows ：the total amount of etherifying agent＆gt;the total amount of alkaline agent＆gt;the percentage of the first addition of ether ＆gt; the percentage of the first addition of alkali ＆gt;90%（volume fraction） of ethanol volume .The optimum process for preparation of HEC is thus gained as fol-lows ：in 80 mL 90% （volume fraction） of ethanol ,firstly add 0 .5 g NaOH to alkalize for 0 .5 h under 40℃ ;heat to 65 ℃ ;add 2 .7 mL 2-chloroethanol and etherify for 1 .5 h;then add 0 .5 g NaOH and 0 .3 mL 2-chloroethanol and etherify for 1 .5 h again .Under these conditions ,the HEC with MS reaching 1 .657 can be gained .And ,it is characterized by FT-IR ,XRD and NM R .