Microwave-assisted Choline Chloride/Lactic Acid Deep Eutectic Solvents Pulping to Produce Wood Fibers with High Degree of Polymerization
Wood fibers with high cellulose polymerization degree(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,and the effects of molar ratio of choline chlo-ride to lactic acid,reaction temperature,reaction time,and water content on cellulose DP were investigated.The results showed that micro-wave heating shortened the time for delignification,which decreased the acid hydrolysis of cellulose in the acidic medium and maintained high cellulose DP of wood fiber.The as-prepared wood fibers had cellulose DP of 1 998 under conditions,which were molar ratio of choline chloride to lactic acid of 1∶11,reaction temperature of 140 ℃,reaction time of 45 min,water content of 3％,as well as zero-distance tensile strength of 261.9 N·m/g,and the paper made by these fibers also exhibited excellent tensile strength of 51.6 MPa and toughness of 2.0 MJ/m3.
万方数据
维普
