稻壳生物炭/醋酸酯淀粉-尿素复合膜的结构和性能

《复合材料学报》优先在线发表论文。

摘  要：采用流延法制备了醋酸酯淀粉:尿素:稻壳生物炭质量比分别为8:1:1、8:2:1、8:4:1的稻壳生物炭(RHBC)/醋酸酯淀粉(AS)-尿素(UR)复合膜，利用SEM、FTIR、XRD、TGA等测试手段对该复合膜的微观形态和结构性能进行了研究，采用流化床喷雾包膜装置制备了RHBC/AS-UR包膜尿素肥并测试了其释放特性。结果表明：RHBC能够均匀的分散于RHBC/AS-UR复合膜中，与UR-AS交联体间形成了“固体桥”的微观结构，结合紧密，同时，RHBC的添加可以提高复合膜的热稳定性。尿素的添加可以提高复合膜的延展性能，当尿素质量添加比例为18.2%时，RHBC/AS-UR复合膜的力学性能达到最佳，断裂伸长率提高了约500%。尿素释放特性试验结果表明，与未包膜尿素相比，不同质量比的RHBC/AS-UR包膜尿素均能有效降低尿素态氮的释放速率，其中，RHBC/AS-18.2%UR包膜尿素在连续24小时浸泡后的总释放率最小(81%)，表现出更好的缓慢释放性能。

关键词：稻壳生物炭；尿素；醋酸酯淀粉；复合膜；性能；释放

Abstract: The rice husk biochar(RHBC)/acetate starch(AS)-urea(UR) composite films were prepared by casting method with different AS : UR : RHBC mass ratios of 8 : 1 : 1, 8 : 2 : 1 and 8 : 4 : 1, respectively. The micromorphology and structure properties were investigated by SEM, FTIR, XRD and TGA. RHBC/AS-UR composite-coated urea fertilizers were prepared in a spouted fluidized bed coating equipment and its release characteristics were tested. The results show that the rice husk biochar can be uniformly dispersed in the RHBC/AS-UR composite film and have good bonding with urea-acetate starch in a “ solid bridge ” structure. In the mean time, the thermal stability of RHBC/AS-UR composite films is enhanced by adding RHBC. The adding of urea can improve the ductility of RHBC/AS-UR composite film. When the dosage of urea is 18.2%, the best mechanical properties of the composite film can be reached and the elongation at break increases by 500%. Compared to the pure urea granule without and with RHBC/AS-UR coating, the urea coated with different mass ratio RHBC/AS-UR composite films can effectively reduce the release rate of urea-N. The total release rate of RHBC/AS-18.2%UR coated urea is the lowest (only 81%), which exhibits better slow-release property.

Keywords: rice husk biochar; urea; acetate starch; composite film; properties; release

作者：钟旋等，华南农业大学 材料与能源学院/农业部能源植物资源与利用重点实验室，广州

通讯作者：王明峰，华南农业大学 材料与能源学院/农业部能源植物资源与利用重点实验室，广州

全文详见中国知网学术期刊优先数字出版。