聚丙烯酸类超强吸水剂的合成与性能研究进展

对聚丙烯酸类超强吸水剂的合成与性能研究进展进行了综述。重点介绍制备方法、稳定剂、交联剂以及共聚单体等的最新发展趋势，同时对此类吸水剂的性能以及其复合材料方面的研究作了简述。此外也评述了其产业化进程及存在的问题。     

Synthesis and Characterization Superabsorbent Polymers Made of Starch,Acrylic Acid,Acrylamide, Poly(Vinyl Alcohol), 2-Hydroxyethyl Methacrylate, 2-Acrylamido-2-methylpropane Sulfonic Acid

Three polymers with excellent absorption properties were synthesized by graft polymerization: soluble starch-g-poly(acrylic acid-co-2-hydroxyethyl methacrylate), poly(vinyl alcohol)/potato starch-g-poly(acrylic acid-co-acrylamide), poly(vinyl alcohol)/potato starch-g-poly(acrylic acid-co-acrylamide-co-2-acrylamido-2-methylpropane sulfonic acid). Ammonium persulfate and potassium persulfate were used as initiators, while N,N′-methylenebisacrylamide was used as the crosslinking agent. The molecular structure of potato and soluble starch grafted by synthetic polymers was characterized by means of Fourier Transform Infrared Spectroscopy (FTIR). The morphology of the resulting materials was studied using a scanning electron microscope (SEM). Thermal stability was tested by thermogravimetric measurements. The absorption properties of the obtained biopolymers were tested in deionized water, sodium chroma solutions of various concentrations and in buffer solutions of various pH.     

A novel method of making PVF porous foam without using the pore forming agent

Different with the conventional method of manufacturing poly(vinyl formal) (PVF) porous foam by using the pore‐forming agents such as wheat or potato starches, a novel method without using the pore‐forming agent is introduced in this article. Through the help of images taken by a scanning electron microscope, the formation process of the present PVF foam will be discussed in terms of the spinodal decomposition (SD) phase separation principle. Additionally, the effect of poly(vinyl alcohol) concentration and reaction temperature on the pore structure of the PVF foam will be investigated. Moreover, the water adsorption capacities of the PVF foams obtained by the present method will be studied in details through the analyses of pore‐size distribution, mechanical modulus, and thermal property. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41270.     

木质素基高吸水性树脂的制备与溶胀行为

以木质素磺酸钠(LS-Na)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、丙烯酸(AA)为原料,N,N-亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发剂,采用微波辐射法,通过接枝共聚合成了具有生物降解性能的LS-g-PAMPS/AA高吸水性树脂。探讨了单体配比、LS-Na用量和单体总用量对LS-g-PAMPS/AA树脂吸水倍率的影响,研究了该树脂在各种盐溶液中的溶胀行为,并利用FTIR和TG等方法分析了该树脂的结构。实验结果表明,当m(AA)∶m(AMPS)=3、LS-Na用量(基于体系总质量,下同)为6%(w)和单体总用量为35%(w)时,LS-g-PAMPS/AA树脂在去离子水和生理盐水中的吸水倍率分别为1 217g/g和125 g/g。LS-g-PAMPS/AA树脂具有较强的热稳定性、耐盐性和盐响应性能,在不同的盐溶液里有良好的可逆行为和多次反复利用性能。     

GA-g-PAMPS/APT复合高吸水性树脂的合成和溶胀行为

以阿拉伯胶(GA)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、凹凸棒石黏土(APT)为原料,采用微波辐射法,通过接枝共聚合成生物质GA-g-PAMPS/APT高吸水性树脂。利用FTIR、XRD和TG分析了树脂的结构和热稳定性能,探讨了树脂在各种盐溶液和不同p H溶液中的溶胀行为,研究了树脂的溶胀速率和反复吸水性能。结果显示:GA、APT与AMPS之间发生了接枝共聚反应,w(GA)=7.5%、w(APT)=10%时树脂在去离子水和生理盐水中的最大吸水倍率分别为783 g/g和91 g/g。树脂在各种盐溶液和不同p H溶液中表现出良好的响应性和可逆性能。适量引入APT能显著提高树脂的热稳定性、溶胀速率、反复吸水性能和p H稳定性。     

膨润土/聚合物复合高吸水材料的研究进展

综述了膨润土／聚合物复合高吸水材料的主要合成工艺路线，并对合成技术进行了评述；同时也指出了这种材料性能今后的改进方向和研究发展的趋势。     

PVA影响海藻酸钠复合水凝胶力学韧性和溶胀性能的研究

以醚化海藻酸钠(ESA)、丙烯酸(AA)、聚乙烯醇(PVA)为单体,N,N-亚甲基双丙烯酰胺为交联剂,过硫酸铵-亚硫酸氢钠为引发剂,水溶液法制备了醚化海藻酸钠-丙烯酸钠-聚乙烯醇复合高吸水性树脂(ESA/NaAA/PVA);采用红外光谱对产物进行了表征,观察了产物的微观相态结构,并测定了树脂的力学性能和溶胀性能.结果表明,体系组分的相容性和相区尺寸的大小与相区的组成有关,当ESA、AA的组成一定时,以w(ESA/NaAA):w(PVA)=88:12比例合成的树脂界面呈分布均匀状态;ESA/NaAA/PVA凝胶的韧性随PVA含量的增加而增大,PVA含量分别占总单体质量的3%、7%、10%、12%时,凝胶分别形变9%、14%、15%、15%时样品被破坏;当w(PVA)＜3.1%时,ESA/AA/PVA树脂在纯水和w(NaCl)=0.9%生理盐水中有较理想的溶胀能力.     

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.