羧甲基纤维素凝胶小球的制备及其对肥料的缓释作用研究

制备一种羧甲基纤维素(CMC)凝胶,以凝胶小球失水率变化反映交联过程。结果表明,交联剂 Fe³⁺ 浓度越高,失水越快且失水率越大。制备凝胶小球时所用 CMC 溶液质量分数越高,失水率越低。DSC 分析凝胶的降温凝固过程表明,CMC 小球中的水以结合状态为主,且制备小球时所用的交联时间越长,凝胶含水率越低。采用硝酸钾作为化肥的模型化合物,释放实验表明,当硝酸钾在 CMC 凝胶中的载量为 5.0% 时,缓释效果明显。

Preparation of Carboxylmethylcellulose Gel Beads and Their Performance on Slow Release of Fertilizer

The preparation of carboxylmethylcellulose(CMC) gel beads was studied by using the water loss ratio to reflect the crosslinking progress.The results indicated that,the rate of water loss was quicker and the ratio of water loss higher following the increase of concentration of Fe3 as the crosslinking agent.Following the increase of content of CMC in the solution for preparing gel beads,the ratio of water loss was lower.The water in CMC gel beads was mainly in a bonding status through analyzing the freezing process of gels with DSC method,and the longer the crosslinking time for preparing the gels,the lower the content of water in gels. The potassium nitrate was used as the model compound of fertilizer in release experiments.The results showed an apparently slow release when the loading amount of potassium nitrate in gel was 5.0 %.