^(60)Co-γ射线引发合成羧甲基纤维素类高吸水树脂实验研究

Experimental study on the carboxymethyl cellulose superabsorbent triggered by^(60)Co-γirradiation

为合成可应用于农业领域的化学节水制剂,以丙烯酸(AA)、丙烯酰胺(AM)、羧甲基纤维素钠(CMCNa)为原材料,N,N’-亚甲基双丙烯酰胺(NMBA)为交联剂,通过^(60)Co-γ射线引发合成高吸水树脂。实验确定了高吸水树脂的最佳制备条件,并对不同的阳离子浓度、压力、环境温度等环境条件下的高吸水树脂的吸水性能进行了分析讨论,还进一步分析了高吸水树脂的吸液速度及在土壤中的保水性能。结果表明:高吸水树脂的最佳制备条件为单体配比m(AA)∶m(AM)∶m(CMCNa)=18∶2∶3,交联剂用量为单体总质量的0.2%,吸收剂量为8.82 kGy;不同阳离子溶液对高吸水树脂的吸水倍率的影响是不一样的,对高吸水树脂吸水抑制作用从大到小依次为Fe^(3+)>Mg^(2+)>Na^(+),因此在施用高吸水树脂时应避免与高价阳离子共混施用;随着环镜压力、温度的增加,高吸水树脂的吸水倍率、保水率均不断下降。制备的羧甲基纤维素类高吸水树脂能够有效减少土壤水分流失,提高土壤的含水量,可为农业抗旱提供技术支持。

In order to synthetize the chemical water-saving agents in agriculture,superabsorbent resin was triggered and synthetized by usingγ-irradiation form a 60 Co source,with acrylic acid(AA),acrylamide(AM),and sodium carboxymethylcellulose(CMCNa)as raw materials,and N,N’-methylene bisacrylamide(NMBA)as crosslinker.The optimal reaction conditions of superabsorbent resin were determined in the experiment,the water absorption properties of superabsorbent resin under different cation concentrations,pressures and ambient temperatures were discussed,and the absorbent speed and water retention property of superabsorbent resin in soil were further analyzed.The results show that the optimal reaction conditions are obtained,when the ratio of monomer is m(AA)∶m(AM)∶m(CMCNa)=18∶2∶3,the amount of crosslinking agent is 0.2%of the total mass of monomer,and the absorbed dose is 8.82 kGy.The influence of different cationic solutions on water absorbency of superabsorbent resin is different,and the inhibitory effect of cations on the absorption efficiency is ranked as:Fe^(3+)>Mg^(2+)>Na^(+).Therefore,it should be avoided to mix with high valence cation when using the superabsorbent resin.The water absorption rate and water retention rate of superabsorbent resin decrease continuously with the increase of the environmental pressure and temperature.The prepared carboxymethyl cellulose superabsorbent resin can effectively reduce soil water loss and improve soil water content,which can provide technical support for agricultural drought resisting.