聚丙烯酸接枝碱木质素基铁肥的制备及其缓释性能

为提高铁元素的累积释放率,以丙烯酸单体接枝无定形高分子碱木质素制备了具有保水、缓释功能的聚丙烯酸接枝碱木质素基铁肥(简写,ALS-G-P(AA)铁肥)。考察了丙烯酸中和度、引发剂用量、交联剂用量、温度、碱木质素接枝率等因素对ALS-G-P(AA)铁肥吸水倍率的影响,研究了ALS-G-P(AA)铁肥在水中的Fe离子的缓释行为。结果表明:最佳制备条件为丙烯酸中和度60%、引发剂用量0.06g、交联剂用量0.03g、温度为60℃、碱木质素接枝率为25%;该产物铁质量分数为7.74mg/g,吸水倍率可达1017g/g。吸水饱和的ALS-G-P(AA)铁肥的肥效期为22d,其在水中铁元素累积溶出特征符合一元二次方程模型,铁元素释放曲线呈"S"形。该研究为高效施用铁肥和碱木质素在农业可降解缓/控释载体领域的应用提供了参考,并有望进一步拓展。

Preparation and release performance of polyacrylic acid grafted alkali lignin-based iron fertilizer

To improve the cumulative release rate of iron,polyacrylic acid grafted alkali lignin-based(ALS-G-P(AA)) iron fertilizer was prepared by acrylic monomer grafted the amorphous alkali lignin.The influences on water absorbency of the materials to neutralization degree of acrylic acid,the dosage of initiator and cross-linking agent,temperature and grafting degree of alkali-lignin were investigated by orthogonal test.Release performance of ALS-G-P(AA) iron fertilizer was researched.The results showed the ideal preparation conditions were as follow:the degree of acrylic acid was 60%,amount of initiator was 0.06 g and the cross-linking agent was 0.03 g,temperature was 60℃ and alkali-lignin grafting was 25%.Water absorbency of ALS-G-P(AA) iron fertilizer was 1 017 g/g,the iron content of which was 7.74 mg/g.Effective release period of water saturated ALS-G-P(AA) iron fertilizer with was 22 days.Iron cumulative released rate of ALS-G-P(AA) iron fertilizer in water fitted a quadric equation.Curve of the iron cumulative release rate was S pattern.The study provides a reference for the efficient application of iron fertilizer,and expanded application of the alkali lignin in agricultural fields of controlled release carriers.