Carbonaceous microsphere-based superabsorbent polymer as filler for coating of NPK fertilizer: Fabrication,properties, swelling,and nitrogen release characteristics

Recently, the use of controlled release fertilizers in agriculture has resulted in huge benefits in plant growth and cultivation. Superabsorbent polymer (SAP)-coated fertilizers have the added advantage in retaining water in soil after irrigation and also reduce the nutrient release rate from soil in a controlled manner. This study aimed to produce a nitrogen–phosphorus–potassium (NPK) fertilizer coated with superabsorbent carbonaceous microspheres polymer (SPC) by inverse suspension polymerization method with water-retention and controlled release properties. Two sets of experiments were conducted: (1) three different weight percentages and (2) different materials. NPK coated with SPC showed increasing water-retention ability with respect to carbon microsphere percentages and retains >80% water at the 30th day of experiment compared with pure NPK and NPK coated with SAP. The slow release behavior of all samples was investigated by induced coupled plasma mass spectrometry spectrometry and results showed that NPK coated with SAP and SPC has a low release rate with <50% nutrient release compared with uncoated NPK at the 30th day. The release mechanism kinetics of NPK coated with SAP and SPC were studied based on the Kosmeyer–Peppas model. The mechanisms approached Fickian diffusion-controlled release as the n value for both samples was less than 0.5. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48396.     

纳米纤化纤维素接枝AMPS及其在高吸水树脂中的应用研究

以纳米纤化纤维素(NFC)为基材,使用硝酸铈铵为引发剂,将抗盐性单体2-丙烯酰胺基-2-甲基丙磺酸(AMPS)接枝到NFC表面,使得接枝后的NFC更亲水和耐盐,并研究了AMPS-NFC在丙烯酸基高吸水树脂中的应用。结果显示,AMPS的用量越多,接枝到NFC表面的AMPS就越多,所制备的吸水树脂的吸收性能越好,与添加TEMPO氧化制备的NFC相比,添加2%用量AMPS-NFC(接枝量为1.725 mmol/g)制得的高吸水树脂的吸收性能有显著提高,其中吸水量由380 g/g增加至620 g/g,吸收去离子水的速度增加13.3%,而吸收0.9%Na Cl的速度增加20.8%。     

交联聚丙烯酸钠与交联羧甲基淀粉复配的高吸水性树脂的制备

采用交联聚丙烯酸钠和交联羧甲基淀粉进行复配,将两种原料按配比经混合、糊化、制片、粉碎、筛分制得复配高吸水性树脂成品.研究表明,最佳制备条件为:交联聚丙烯酸钠与交联羧甲基淀粉的质量比为8,糊化时的加水量为400g/g,糊化25min,制片温度为140℃.此产品将这两种高吸水性树脂组分的优缺点互补,生产成本低、安全性好,其吸蒸馏水倍率为800～1100倍,吸生理盐水的倍率为60～95倍.     

高吸水复合材料吸水速度的研究

本研究使用聚丙烯酰胺与蒙脱土复合而成的高吸水复合材料(简称SAPC)对其在各种情况下的吸水速度进行初步的探讨,测定了材料的吸水速度,讨论了水溶液中离子(盐)和醇浓度以及温度、时间等各种因素对SAPC吸水率的影响及影响吸水速度的原因。     

鱼蛋白高吸水剂的吸湿保湿研究

利用鱼蛋白与丙烯酸通过水溶液聚合法,以N,N-亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发荆,接枝共聚制备鱼蛋白高吸水荆(FP-g-PAA),并对其结构进行了IR分析.通过与变色硅胶进行比较,对其吸湿保湿性能进行了初步研究.结果发现,该吸水剂具有较大的吸湿容量和良好的吸湿稳定性,IR表明其具有大量的亲水基团,在88%±1%相对湿度下的平衡吸湿量达到了2.65g/g,保湿性能好,优于广泛使用的变色硅胶,在吸湿保湿方面具有一定的应用潜力,为开发多功能干燥剂提供了实验参考.     

Conversion of Fine Particle Waste of Water-Absorbents to Value-Added Oil-Absorbents

This is a preliminary report on conversion of fine particle waste of superabsorbent polymer (SAP) hydrogels to value-added oil-absorbing organogels via a facile and green approach. Thus, SAP was hydrophobically modified with different contents of an R₄N⁺Br^– to incorporate long alkyl groups to the polymer structure. FTIR and DSC were employed to study the structural and thermal characteristics of the product. Swelling measurements verified that the SAP could be easily converted to efficient organophilic samples with absorption capacity up to 6 g/g in toluene and 4 g/g in crude oil media. Therefore, the product may be employed in environmental decontamination.     

交联剂对魔芋超强吸水剂凝胶强度和吸水倍率的影响

以魔芋葡甘聚糖为基体,丙烯酸为单体,过硫酸钾为引发剂,分别以N,N’-亚甲基双丙烯酰胺(MBA)、甘油、聚乙二醇600(PEG600)、Ca(NO3)2.4H2O为交联剂,制备魔芋超强吸水树脂(KSAP),测试其凝胶强度和吸水倍率,同时对其进行红外光谱结构表征。实验表明,以MBA为交联剂制得的KSAP的凝胶强度最大,可达到153.7g/cm2,以甘油为交联剂制得的KSAP的吸水倍率最高,可达1201g/g。     

魔芋超强吸水剂的生物降解性能研究

采用霉菌侵蚀法和土壤掩埋法对自制的吸水性材料魔芋超强吸水剂(KSAP)的生物降解性能进行了研究.结果表明,KSAP在霉菌侵蚀和土壤掩埋的条件下均具有可生物降解性,它的使用可减少环境污染.     

反相悬浮聚合法制备P(AM-co-AMPS)水凝胶球

采用反相悬浮聚合法合成丙烯酰胺与2-丙烯酰胺-2-甲基丙磺酸共聚高吸水性树脂P(AM-co-AMPS),研究反应条件对高吸水性树脂吸水性能的影响.结果表明在环己烷用量为100 g、蒸馏水20 g、AMPS用量为6.75 g、丙烯酰胺用量为2.25 g、石蜡0.5 g、搅拌速率为400 r/min、反应4 h情况下,当引发剂与单体用量之比为0.4%、交联剂与单体用量之比为0.08%、分散剂与单体用量之比为0.8%、反应温度70℃时,可得到平均粒径为0.7 mm的均匀分散的P(AM-co-AMPS)水凝胶球,其吸蒸馏水倍率为315 g/g,吸0.9% NaCl水溶液为33 g/g.     

黄原胶改性制备高吸水性树脂的研究

以丙烯酸(AA)和丙烯酰胺(AM)为黄原胶(XG)的接枝改性剂,采用反向悬浮聚合法制备了高吸水性树脂——接枝改性共聚物(XG-g-AA/AM)。采用U*10(104)均匀设计法对XG-g-AA/AM的合成工艺进行了优化。结果表明:XG-g-AA/AM的最佳合成条件为m(AA)=10.0 g、w(引发剂)=0.5%(相对于单体总质量而言)、AA中和度80%和反应温度60℃,此时XG-g-AA/AM的吸水倍率为890.1 g/g、吸盐水倍率为172.2 g/g;热失重分析(TGA)结果显示,XG-g-AA/AM的热稳定性优于XG;扫描电镜(SEM)观测结果显示,XG-g-AA/AM表面形成的多孔网络结构,有利于其对水分子的接触与吸附。