改性酰化壳聚糖缓释肥包膜材料的制备与表征

Preparation and Characterization of Modified Acylated Chitosan Coating Materials of Fertilizers

壳聚糖与辛酰氯酰化反应,制备低取代度的酰化壳聚糖。通过元素分析计算酰化壳聚糖的取代度,并用红外光谱、核磁共振、尿素渗透测试对其结构及渗透性能进行分析和表征。以戊二醛为交联剂,制备了一系列酰化交联壳聚糖膜,用吸水倍率、接触角、X射线衍射仪、热重分析、尿素渗透等对其性能进行分析表征。结果表明,交联使酰化壳聚糖热稳定性提高;酰化交联壳聚糖缓释包膜材料结晶度下降,疏水性提高;随戊二醛含量增加,尿素累积渗透量下降,7 d内尿素累积渗透量由74.7%降低至34.2%,28 d时尿素累积渗透量为76.7%,改性酰化壳聚糖膜缓释性能良好。

Acylated chitosan was synthesized by reaction of chitosan and caprylyl chloride. The chemical structures of these polymers were characterized by elemental analysis,FT-IR and1H-NMR. The permeability of the membranes was determined by measuring the diffusion of urea. Acylated chitosan was modified by crosslinking with glutaraldehyde and their characterization and properties were confirmed by water absorption ratio,contact angle,XRD,TG. The results indicate that the crystallinity is decreased and hydrophobicity is increased by crosslinking. The crosslinking enhances thermal properties. With the increasing content of glutaraldehyde,the accumulated permeation amount of urea drops rapidly from 74. 7% to 34. 2% in 7 d. The accumulated permeation amount of urea is 76. 7% on the 28 th day,indicating that the crosslinked and acylated chitosan films have an excellent controlled-release property.