超声波辅助纤维素系高吸水树脂的合成及表征

选用可生物降解的纤维素为基本骨架,利用硝酸铈铵作为引发剂处理纤维素,采用超声波辅助方法使其与丙烯酸发生接枝共聚反应,合成高吸水树脂.研究超声波功率、引发剂用量、丙烯酸与微晶纤维素的质量比、中和度、交联剂用量对树脂吸水倍率的影响,并对纤维素系高吸水树脂进行红外光谱和扫描电镜分析.结果表明,最佳工艺条件:超声波功率为500 W,引发剂用量为1.8 mL,丙烯酸与微晶纤维素的质量比为3.0:2.0,中和度为50％,交联剂质量分数为0.10％.此条件下制得的吸水树脂的吸蒸馏水倍率为486倍,吸自来水倍率为173倍.经红外光谱和扫描电子显微镜综合分析,证明超声波处理可以使得微晶纤维素表面发生变化,促进微晶纤维素与丙烯酸的固相接枝共聚,合成的纤维素系高吸水树脂保留了微晶纤维素分子骨架和聚丙烯酸各自的特性,在纤维素大分子表面和无定型区引发了接枝聚合.

Preparation and Characterization of Cellulose Based Absorbent Grafting Copolymerization Under Ultrasonic Wave

Biodegradable cellulose was selected as a basic skeleton, using ceric ammonium nitrate as an initiator treated cellulose, the water-absorbent resin was synthesized by grafting copolymerization with acrylic acid by ultrasound-assisted method. The effects of ultrasonic power, initiator concentration, the ratio of monomer concentration to microcrystalline cellulose, degree of neutralization and crosslinking agent dosage on the water absorbency of the resin were investigated, and the water-absorbent resin was analyzed by infrared spectrum and scanning electron microscope. The results showed that the optimal process conditions were as follows: ultrasonic power was 500 W, initiator concentration was 1.8 mL, the ratio of monomer concentration to microcrystalline cellulose was 3.0:2.0, neutralization degree was 50%, and mass fraction of crosslinking agent was 0.10%. Under these conditions, the absorbency of the absorbent resin was 486 times of distilled water and 173 times of tap water. The structure and properties of grafted product were characterized by IR and SEM, and the results showed that the ultrasonic treatment could lead to the change on the surface of the microcrystalline cellulose, promote microcrystalline cellulose and solid phase graft copolymerization of acrylic acid, the synthesized cellulose resin retained respective characteristics of the microcrystalline cellulose molecular skeleton and polyacrylic, a graft polymerization occurred on the cellulose macromolecular surface and the amorphous zone.