采用反相悬浮聚合法,以(NH4)2S2O8-NaHSO3为引发剂,N,N’-亚甲基双丙烯酰胺(MBA)为初体交联剂,环氧氯丙烷(ECH)为表面交联剂,单体丙烯酸(AA)和丙烯酰胺(AM)与羧甲基纤维素钠(CMC)接枝共聚,制得含有阴离子亲水基团和非离子亲水基团的颗粒状高吸水性树脂,研究了表面交联剂的加入量及表面交联时间对树脂吸水性能、保水性能及使用寿命的影响。结果表明表面强化交联与单一交联的产品相比,具有更高的吸液率、吸液速率、脱水速率和使用寿命。通过表面强化交联,树脂的吸水能力可提高一倍以上。在优化的反应条件下,所得树脂在自来水中的吸水率为114 g g 1,在1%NaCl盐水中的吸水率为69 g g 1,吸收至半饱和量的时间小于15 s,吸收至饱和量只需1 min。吸水后的树脂无黏性、分散性好,具有一定的凝胶强度。
A kind of enhanced surface crosslinking super-absorbent polymer having anionic and non-ionic hydrophile groups was synthesized via graft copolymerization reaction of acrylic acid (AA)/acrylamide (AM) onto sodium carboxymethylcellulose (CMC) by means of inverse suspension polymerization in the presence of (NHa)2S2Os-NaHSO3 as initiator, N,N'-methylenebisacrylamide (MBA) as initial crosslinker and epichlorohydrin (ECH) as surface crosslinker. The influences of the amount and adding time of the surface crosslinker on water absorbency, water retention performance and service life were investigated in detail. Compared with single crosslinking product, the surface crosslinking product has higher absorbency, absorption rate, dehydration rate and longer service life. The results show that the absorbencies of the product synthesized under the optimal reaction conditions are 114 g·g^-1 in tap water, 69 g·g^-1 in 1% NaCl solution, respectively, and the half saturated time is less than 15 s. The product after absorption is dispersible, non-sticky with certain gel strength.