微波辅助低共熔溶剂法制备高聚合度木质纤维

Microwave-assisted deep eutectic solvents pulping to produce wood fibers with high degree of polymerization

关键词:  微波  低共熔溶剂  纤维素聚合度  力学性能

Key Words:microwave  deep eutectic solvents  cellulose degree of polymerization  mechanical properties.

摘要:以云杉木片为原料,以氯化胆碱/乳酸为反应液,采用微波辅助低共熔溶剂制浆方法制备高聚合度木质纤维,考察了氯化胆碱与乳酸的摩尔比、反应温度、反应时间和水掺杂量等制浆工艺参数对纤维素聚合度的影响。结果表明,在氯化胆碱与乳酸的摩尔比为1:11,反应温度140℃,反应时间45 min,水掺杂量3 wt% 时,制备的木质纤维聚合度最高(1998)。微波加热有效地缩短了脱木质素反应所需的时间,从而减少了纤维素的酸降解水解,有效地保留了木质纤维的聚合度。所得的木质纤维的零距抗张强度达到261.9 N?m?g-1^,其抄造的纸张也呈现出良好的拉伸应力(51.6 MPa)和韧性(2.0 MJ?m-3⁾。

Abstract:Wood fibers with high cellulose degree of polymerization (DP) were prepared via microwave-assisted deep eutectic solvents pulping method using spruce wood chips as material and choline chloride/lactic acid as reaction liquid. The effects of molar ratio of choline chloride to lactic acid, reaction temperature, reaction time and water content on the DP were investigated. The consequence showed that DP reached 1998 under conditions of molar ratio of choline chloride to lactic acid of 1:11, reaction temperature of 140℃, reaction time of 45 min, water content of 3 wt%. Microwave heating shortened the time for delignification, which decreased the acid hydrolysis of wood fiber in the acidic medium and maintained high DP of wood fiber. The as-prepared wood fibers with high DP have high zero-distance tensile strength of 261.9 N?m?g^-1, and the paper made by these fibers also exhibited an excellent tensile strength of 51.6 MPa and toughness of 2.0 MJ?m-3^.