ABSTRACT

A novel biodegradable super absorbent polymer (SAP) was synthesized by γ-poly (glutamic acid) (γ-PGA) and poly (ethylene glycol) with the units of glycidyl ether as chain ends (PEGGE). The resultant γ-PGA SAPs with different PEGGE contents were characterized and their effects on soil total available water (TAW) were investigated. The γ-PGA SAP was synthesized at 45 °C for 48 h when γ-PGA was 160 g L⁻¹ (pH = 4.9) and the minimum mass of PEGGE was 20% of the γ-PGA mass. When the PEGGE increased from 20% to 60%, the water absorption rate (WAR) of γ-PGA SAP in distilled water and 0.9% NaCl solution gradually decreased from 651.16 g g⁻¹ to 302.91 g g⁻¹ and from 44.83 g g⁻¹ to 32.9 g g⁻¹ respectively. The γ-PGA SAP with 40% PEGGE had the highest WAR after being reused six times. The field water capacity (FC) and TAW increased with the increasing γ-PGA SAP content; however, when the same amount of γ-PGA SAP was added to the soil, the FC and TAW in the soil gradually decreased with the increasing PEGGE in the γ-PGA SAP. The γ-PGA SAP with a proportion of 0.15% in the soil presented the largest soil WAR.

摘要

以缩水甘油醚为链端（PEGGE）为单元的γ-聚（谷氨酸）（γ-PGA）和聚（乙二醇）合成了一种新型可生物降解的高吸水性聚合物（SAP）。表征了所得的具有不同PEGGE含量的γ-PGA SAPs，并研究了它们对土壤总有效水（TAW）的影响。当 γ-PGA 为 160 g L ^-1 (pH = 4.9) 且 PEGGE 的最小质量为 γ-PGA 质量的 20% 时，γ-PGA SAP 在 45 °C 下合成 48 小时。当 PEGGE 从 20% 增加到 60% 时，γ-PGA SAP 在蒸馏水和 0.9% NaCl 溶液中的吸水率（WAR）从 651.16 gg ^-1逐渐下降到 302.91 gg ^-1和从 44.83 gg ^-1到32.9 克^-1分别。含有 40% PEGGE 的 γ-PGA SAP 在重复使用 6 次后 WAR 最高。田间持水量（FC）和TAW随着γ-PGA SAP含量的增加而增加；然而，当土壤中添加相同量的γ-PGA SAP时，随着γ-PGA SAP中PEGGE的增加，土壤中的FC和TAW逐渐降低。土壤中含量为0.15%的γ-PGA SAP表现出最大的土壤WAR。