聚丙烯酸钠/高岭土复合高吸水性树脂的制备、结构与性能

以丙烯酸和高岭土为原料,用反相悬浮聚合法合成了聚丙烯酸钠/高岭土复合高吸水性树脂。研究了加入高岭土的聚丙烯酸钠复合高吸水性树脂合成中反应温度、中和度、交联剂用量、引发剂用量、高岭土添加量等影响树脂吸水性能的主要因素。结果表明,用反相悬浮聚合法合成的复合高吸水性树脂后处理容易,树脂的吸水率达到512g/g,吸盐水率达到81g/g,吸水速度比不加高岭土提高20%,保水能力提高15%,在250℃加热30min仍能保持原吸水率的95%。用IR和TEM研究了复合高吸水性树脂的表面和结构,TEM显示高岭土的加入对树脂颗粒大小和形状有较大的影响,IR初步表明聚丙烯酸与高岭土产生了交联。     

聚丙烯酸盐/高岭土高吸水性树脂的合成与性能研究

以丙烯酸和高岭土为原料，用溶液法合成复合高吸水性树脂。研究了单体中和度、高岭土加入量、交联剂用量、引发剂用量等影响吸水倍率的主要因素。加入高岭土粉体的复合型高吸水性能脂用溶液法聚合，产物不易粘壁，后处理方面优于纯的交联聚丙烯酸盐树脂。     

聚丙烯酸钠∕高岭土复合高吸水性树脂的制备、结构与性能

以丙烯酸和高岭土为原料,用反相悬浮聚合法合成了聚丙烯酸钠/高岭土复合高吸水性树脂.研究了加入高岭土的聚丙烯酸钠复合高吸水性树脂合成中反应温度、中和度、交联剂用量、引发剂用量、高岭土添加量等影响树脂吸水性能的主要因素.结果表明,用反相悬浮聚合法合成的复合高吸水性树脂后处理容易,树脂的吸水率达到512 g/g,吸盐水率达到81 g/g,吸水速度比不加高岭土提高20%,保水能力提高15%,在250 ℃加热30 min仍能保持原吸水率的95%.用IR和TEM研究了复合高吸水性树脂的表面和结构,TEM显示高岭土的加入对树脂颗粒大小和形状有较大的影响,IR初步表明聚丙烯酸与高岭土产生了交联.     

水溶液聚合高岭土复合聚丙烯酸钠-丙烯酰胺高吸水性树脂的研究

以N ,N-亚甲基双丙烯酰胺为交联剂 ,过硫酸铵 /亚硫酸氢钠为氧化还原引发剂 ,采用水溶液聚合法合成出高岭土复合聚丙烯酸钠 -丙烯酰胺高吸水性复合树脂。研究了高岭土的添加量对复合树脂的吸水性、吸水速度及保水性等的影响 ,并用TGA和DSC分析研究了高岭土复合高吸水树脂的保水性和脱水动力学     

聚丙烯酸钾-高岭土高吸水性树脂的制备及表征

以丙烯酸钾、高岭土为原料,通过水溶液聚合法合成高岭土-聚丙烯酸钾复合高吸水性树脂。并对单体的中和度、高岭土的添加量、交联剂用量和引发剂用量对复合高吸水性能的影响因素进行了研究。实验结果表明：当单体的中和度为85％,引发剂用景为0．25％,交联剂用量为0．015％时,可以合成出性能较好的复合型高吸水性树脂,其在蒸馏水中的吸水倍率可达728g／g。     

水溶液聚合高岭土复合高吸水性树脂的研究

以N，N-亚甲基双丙烯酰胺为交联剂，过硫酸铵／亚硫酸氢钠为氧化还原引发剂，采用水溶液聚合法合成出高岭土复合聚丙烯酸钠．丙烯酰胺高吸水性复合树脂。研究了高岭土的添加量和交联剂用量等因素对复合树脂的吸水性、吸盐性、保水性等的影响。热重分析(TGA)表明加入高岭土可提高复合树脂的保水性。(FTIR)表明聚丙烯酸与高岭土产生了表面化学交联，X射线衍射(XRD)表明单体在聚合过程中未能插入到高岭土层间。     

HEMA-AA水溶液聚合合成高吸水性树脂研究

以甲基丙烯酸－β－羟乙脂（HEMA）和丙烯酸（AA）为原料，过硫酸铵为引发剂，N，N'-亚甲基双丙烯酰胺为交联剂，采用水溶液聚合法可合成HEMA－AA共聚高吸水性树脂。考察了有关聚合条件对高吸水性树脂性能的影响，HEMA的加入对树脂的耐盐性能有提高。     

荔枝核淀粉接枝丙烯酸合成高吸水树脂

采用静态水溶液聚合法成功制备了一种水凝胶型荔枝核淀粉接枝丙烯酸高吸水树脂(SAP)。研究发现,乙二胺四乙酸二钠(EDTA)的加入不仅显著提高淀粉/高岭土复合吸水性树脂的产率,而且使其吸水性得到提高。详细研究了不同反应条件对产物吸水性和产率的影响,获得了复合吸水性树脂的最佳合成工艺,在最优条件下合成的树脂吸收自来水、纯水、生理盐水和人工尿液的倍率分别为(764±21)、(3 152±26)、(128±2)、(110±1)g/g。分别利用傅里叶变换红外光谱仪(FTIR)、热重分析仪、扫描电镜、能谱和碘染色等对复合吸水性树脂进行定性分析,结果表明:丙烯酸成功接枝到淀粉分子链上,同时保留了部分淀粉的分子链结构;高岭土成功与淀粉基高吸水树脂复合,产物热稳定性有所提高。     

反相悬浮法合成PNaAA高吸水性树脂的聚合工艺

采用反相悬浮法合成PNaAA高吸水性树脂。研究了聚合初始温度、搅拌转速、分散剂的种类及用量等对聚合稳定性、树脂粒径和吸水性能的影响。结果表明:在聚合初始温度为50℃、以Span-60为分散剂、分散剂用量为4.4%(相对于单体质量)及搅拌转速为500r.min-1的条件下,聚合过程稳定性好,树脂粒径适中、饱和吸水率高、吸水速度快。     

丙烯酸钠-丙烯酰胺高吸水树脂的合成与性能

以过硫酸钾为引发剂、N,N-亚甲基双丙烯酰胺(NNMBA)为交联剂,采用水溶液聚合法制备聚丙烯酸钠-丙烯酰胺高吸水性树脂,研究了丙烯酸与丙烯酰胺比例、单体浓度、引发剂用量、交联剂用量以及聚合温度对树脂吸水性能的影响。制备的高吸水性树脂吸蒸馏水为593g·g-1,吸自来水为260g·g-1,吸0.9%Na Cl溶液为66.7g·g-1。     

Synthesis,characterization, and swelling behavior of alginate‐g‐poly(sodium acrylate)/kaolin superabsorbent hydrogel composites

A novel superabsorbent composite based on sodium alginate and the inorganic clay kaolin was synthesized via the graft copolymerization of acrylic acid (AA) in an aqueous medium with methylene bisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. The effects of reaction variables, such as the MBA, AA, and APS concentrations and the alginate/kaolin weight ratio, on the water absorbency of the composite were systematically optimized. Evidence of grafting and kaolin interactions was obtained by a comparison of the Fourier transform infrared spectra of the initial substrates with that of the superabsorbent composite, and the hydrogel structure was confirmed with scanning electron microscopy. The results indicated that with an increasing alginate/kaolin weight ratio, the swelling capacity and gel content increased. The effects of various salt media were also studied, along with the swelling kinetics. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

壳聚糖接枝聚丙烯酸钠/高岭土复合树脂的吸水性能

利用溶液聚合法制备了壳聚糖接枝聚丙烯酸钠/高岭土复合树脂,研究了复合树脂在蒸馏水中的吸水速率、重复吸水性能和人工尿液中的吸水倍率,以及在不同温度、不同电解质溶液离子强度和不同pH值的环境下复合树脂的吸水性能。结果表明,复合树脂的吸水速率较慢,在多次重复吸水后吸水性能也逐渐降低,在人工尿液中的吸水倍率高于聚丙烯酸钠树脂,低于壳聚糖接枝丙烯酸钠树脂;随着温度的升高,复合树脂的吸水能力增强,超过50℃后变化较小;树脂的吸液倍率随着电解质溶液浓度和价态的增大而下降;随着pH值的增大而出现驼峰,在pH=3.5和pH=8.5处分别出现吸液倍率最大值。     

Preparation of poly(acrylic acid‐co‐acrylamide)/kaolin and release kinetics of urea from it

A series of poly(acrylic acid‐co‐acrylamide)/kaolin [poly(AA‐co‐Am)/kaolin] composites were prepared by aqueous solution copolymerization of partially neutralized acrylic acid and acrylamide in the presence of kaolin nanopowder, which was synthesized to act as a release carrier of urea fertilizer. The superabsorbent composite was swollen in aqueous solution of urea to load urea, and the effect of urea concentration on the swelling was investigated. Furthermore, the effects of the contents of crosslinker, kaolin, and acrylamide, the neutralization degree of acrylic acid, and temperature, pH, and ionic strength of release medium on water absorbency and diffusion coefficient of urea release from poly(AA‐co‐Am)/kaolin were studied systematically. It was found that urea loading percentage could be adjusted by urea concentration of swelling medium, and urea diffusion coefficient could be regulated through the contents of crosslinker, kaolin, and acrylamide, and the neutralization degree of acrylic acid. Additionally, temperature and ionic strength of release medium may also affect the urea release process. The conclusions obtained could provide theoretical basis for urea diffusion behavior in superabsorbent used in agriculture. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

AM-g-CMC/高岭土高吸水性复合材料研究

用硝酸铈铵作引发剂，通过水溶液聚合法制备了羧甲基纤维素接枝丙烯酰胺共聚物(AM-g-CMC)／高岭土高吸水性复合材料。研究了羧甲基纤维素与丙烯酰胺的配比，以及引发剂、交联剂、高岭土和皂化碱用量对复合材料吸水率的影响。用红外光谱表征复合材料的结构，用电子显微镜观察复合材料的形态。结果表明，制得的高吸水性复合材料吸蒸馏水达1182g／g，吸氯化钠水溶液(质量分数为0．9％)达92g／g，     

油田堵漏用高吸水树脂的合成与吸水性能

用水溶液聚合法制备了丙烯酰胺(AM)/2-丙烯酰胺基-2-甲基丙磺酸(AMPS)/高岭土三元复合型高吸水树脂,最佳制备条件为:w(AM)=20%,w(N,N′-亚甲基双丙烯酰胺)=0.08%,w(过硫酸铵)=0.6%,反应温度40℃。优选样在105℃烘干6h后,在室温下的吸蒸馏水倍数和吸w(NaCl)=0.9%水溶液倍数分别达到1634g/g及138g/g。考察了温度、电解质浓度、树脂粒径、不同种类的矿物、高岭土质量分数以及溶液pH对吸水树脂吸水性能的影响,测试了不同温度下树脂的吸水率和保水率。通过添加有机羧酸CA和调整树脂的粒径大小,制备了一种吸水速率可控的油田堵漏用高吸水树脂。红外光谱分析表明,有机羧酸CA能有效地与树脂复合,形成共聚物。     

有机/无机复合高吸水树脂的制备及性能

以玉米淀粉、羧甲基淀粉钠和丙烯酸为主要原料,同时加入活性高岭土,采用水溶液共聚法制备了复合高吸水树脂。考察了接枝共聚过程的影响因素,确定了合成树脂的最优工艺条件,合成的树脂吸水倍率为1195.4 g·g^-1,吸盐水(质量分数为0.9%的氯化钠溶液)倍率为90.1 g·g^-1。借助于傅里叶红外(FTIR)、扫描电镜(SEM)及热重-差热分析(TG-DTA)技术对合成树脂进行了性能和结构表征,并考察了样品的热稳定性。结果表明,高吸水树脂在100℃下具有良好的热稳定性,所制备样品具有商业化前景。     

Hydrogel composites based on linear low‐density polyethylene‐g‐poly (acrylic acid)/Kaolin or halloysite nanotubes

Two series of superabsorbent hydrogel composites were prepared using waste linear low‐density polyethylene, acrylic acid, and two types of clays including kaolin and halloysite nanotube (HNT) through emulsion polymerization. The effects of the clay content on Water absorbency were investigated to obtain a high swelling capacity. The prepared samples were characterized using FTIR, SEM, thermogravimetric analysis, XRD, solid‐state ¹³C Nuclear Magnetic Resonance spectroscopy, and ²⁹Si NMR. SEM characterization of the samples showed that the hydrogel composites have more pores and a higher swelling ratio than the clay‐free hydrogels. The hydrogel composite containing kaolin had higher water absorbency compared to the hydrogel composites with HNT. The swelling behavior of the hydrogel composite was investigated in various saline solutions. The hydrogel composite containing 5 wt % kaolin had the highest water absorbency (760 g/g in distilled water). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40101.     

Controlled release NPK compound fertilizer with the function of water retention

Controlled release nitrogen, phosphorus and potassium (CRNPK) compound fertilizer with the function of water retention was prepared, which possessed the core/shell structure. Its core was urea formaldehyde (UF) and polyphosphate potassium (PAK) fertilizer, and the shell was P(acrylic acid-co-acrylamide)/kaolin (P(AA-co-AM)/kaolin) superabsorbent composite. Analysis results showed that the N, P and K contents were 11.3, 21.1 (shown by P₂O₅) and 8.6 (shown by K₂O) wt%, respectively. The synthesis conditions of inversion suspension polymerization were studied systematically. The water absorbency of the product was 91 g/g in tap water. The swelling rate, slow release and water retention properties of CRNPK were also investigated. Additionally, the effect of temperature on the nutrients release behaviors was studied. The results showed that the product had high initial swelling rate, and the product not only had a good slow release property but also excellent water retention ability, which could effectively improve the utilization of fertilizer and water resource at the same time.