玉米秸秆纤维素基保水缓释肥的制备及性能研究

Preparation and properties of corn stover cellulose-based water-retaining and slow-release fertilizer

以玉米秸秆纤维素(CSC)和丙烯酸(AA)为原料,采用溶液聚合法制备可降解高吸水聚合物玉米秸秆纤维素-g-聚丙烯酸(CSC-g-PAA)。通过扫描电镜(SEM)和傅里叶变换红外光谱(FTIR)对CSC-g-PAA材料的形貌和结构进行表征。进一步研究CSC-g-PAA在土壤中的持水性、保水性以及降解性。结果表明,CSC-g-PAA在去离子水中的吸水率可达702.89 g/g, 5次循环后CSC-g-PAA的吸水率仍然为初始吸水率的47.27%;添加土壤3%(质量分数)的CSC-g-PAA,土壤持水率为70.51%,36 d后保水率为15.50%;CSC-g-PAA在土壤中50 d的降解率为24.14%。采用液体浸渍法CSC-g-PAA尿素最高负载率为81.76%,具有优异的缓释性能,符合M_(t)/M_(∞)=Ktn模型。CSC-g-PAA能集吸水、保水和负载养分及缓释的功能于一体,在农业生产中具有节水、减施增效的巨大潜力。

A degradable superabsorbent polymer of corn stover cellulose graft polyacrylic acid(CSC-g-PAA)by solution polymerization using corn stover cellulose(CSC)and acrylic acid(AA)as raw materials.The structure and morphology of CSC-g-PAA were characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric analysis(TGA).The water holding,water retention and degradability of CSC-g-PAA in soil were studied.The results showed that the water absorption rate of CSC-g-PAA in deionized water could reach 702.89 g/g,and that of CSC-g-PAA after five cycles was about 47.27%of the initial water absorption rate;the water holding rate of soil containing CSC-g-PAA content of 3%was 70.51%,and after 36 d,the water retention rate was 15.50%;the degradation rate of CSC-g-PAA was 24.14%after 50 d.The maximum loading rate of urea by liquid impregnation method is 81.76%.CSC-g-PAA Loaded with urea has slow-release effect on the release of urea in deionized water,and its slow-release performance accords with M_(t)/M_(∞)=Kt n model.Obviously,CSC-g-PAA can integrate the functions of water absorption,water retention,nutrient loading and slow release,which has great potential of saving water,reducing fertilizer application and increasing efficiency in agricultural production.