反相悬浮法合成高耐盐性的超强吸水剂

以多元醇为交联剂、烷基磷酸钠 -司盘 (NP -SP)为复合悬浮稳定剂、丙烯酸 (AA)为单体、过硫酸铵 (APS)为引发剂、环己烷为分散介质 ,采用反相悬浮法合成耐盐性聚丙烯酸钠超强吸水剂。研究了交联剂类型和用量 ,悬浮稳定剂类型、用量和质量比 ,引发剂浓度 ,单体中和度(丙烯酸钠占单体总量的摩尔分数 ) ,聚合温度等对产品物理性状、耐盐性及体系稳定性的影响。当 ρ(多元醇 ) =0 5 3g/L、ρ(NP -SP) =0 0 0 8～ 0 0 1g/mL、m(SP)∶m(NP) =(2 3～ 4 0 )∶1 0、c(APS) =40 5mmol/L、单体中和度x(丙烯酸钠 ) =79 2 %、聚合温度 70～ 76℃时 ,体系稳定 ,产品成球性好 ,吸盐水 (生理盐水 )率 199mL/ g ,吸水 (蒸馏水 )率 86 4mL/ g ,耐盐性高于其他交联剂交联型产品。     

Inverse suspension polymerization of sodium acrylate: Synthesis and characterization

Crosslinked Poly(acrylic acid) was synthesized by inverse suspension polymerization. This process was investigated to determine the influence of different parameters like temperature, stirring speed, solution pH, and crosslinker concentration and to obtain the best control of the kinetics. An aqueous phase containing partially neutralized acrylic acid, crosslinking agent, and initiator agent was dispersed in an organic phase and stabilized by a surfactant. The inverse suspension was carried out in heptane as the organic phase with a different ratio of neutralization of the monomer, different crosslinker concentrations, and several stirring speeds. The polymerization was initiated by potassium persulfate (K₂S₂O₈) with N‐N′‐methylenebisacrylamide (MBA_C) as the crosslinker and sorbitan monooleate as the surfactant. The influence of several parameters on the bead size and the swelling capacity was investigated. Particle diameters ranged from 10 to 130 μm. The kinetic results obtained by differential scanning calorimetry showed that conversion and polymerization rates are a function of the solution pH, and they fell when the concentration of the crosslinking agent was higher than 7.5% in the mass of MBA_C. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2621–2630, 2000     

静态反相悬浮聚合法合成聚丙烯酸钠

以过氧化氢为引发剂,以食用植物油如菜子油、花生油、茶油、葵花油、大豆油或者玉米油为分散相,采用静态反相悬浮聚合工艺合成聚丙烯酸钠,研究了引发剂用量、分散相以及反应温度对聚丙烯酸钠分子量的影响。结果表明,随过氧化氢浓度增大、丙烯酸钠单体浓度降低、聚丙烯酸钠的分子量降低;玉米油为分散相时聚丙烯酸钠的分子量最大;随反应温度升高,聚丙烯酸钠的分子量增大;但反应温度超过60℃时,聚丙烯酸钠的分子量随反应温度升高而降低。     

Superabsorbent polymeric materials VII: Swelling behavior of crosslinked poly[sodium acrylate‐CO‐trimethyl methacrylamido‐propyl ammonium iodide] in aqueous salt solutions

A series of xerogels based on sodium acrylate (SA), cationic comonomer trimethyl methacrylamidopropyl ammonium iodide (TMMAAI), and N,N‐methylene‐bis‐acrylamide (NMBA) were prepared by inverse suspension polymerization. The water absorbency and the swelling behavior for these highly absorbent polymers in deionized water and various saline solutions were investigated. Results indicated that the water absorbency increased when a small amount of TMMAAI monomer was introduced into the SA gel. The water absorbency decreased with increase in TMMAAI content, but the contrary result was observed for initial absorption rate. Moreover, with more crosslinking agent, the water absorbency was lower. Finally, the adsorption of copper ion by these gels was also investigated. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1749–1759, 2000     

Influence of reaction parameters on water absorption of neutralized poly(acrylic acid‐co‐acrylamide) synthesized by inverse suspension polymerization

Highly water‐absorbing polymers of neutralized poly(acrylic acid‐co‐acrylamide) were synthesized in an effort to investigate the influences of reaction parameters on water absorption. In addition, the extent of water absorption and the absorption rate were studied to determine their relationship with the reaction parameters. This article explains the synthesis technique, characterization of the water‐absorbing copolymers, and their properties. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1349–1366, 1999     

Superabsorbent polymeric materials. XIII. Effect of oxyethylene chain length on water absorbency for the sodium acrylate and poly(ethylene glycol) methyl ether acrylate (PEGMEAn) copolymeric gels

In a previous study, we prepared a series of xerogels based on sodium acrylate (NaA) and 2‐hydroxyethyl methacrylate (HEMA, OE = 1) or poly(ethylene glycol) methacrylate (PEGMA, OE = 6) with different oxyethylene (OE) units. The effect of the contents of HEMA and PEGMA in the copolymeric gel on the swelling behavior in deionized water and various saline solutions was studied. Their results showed that the water absorbencies for these two series gels were effectively improved by adding a small amount of HEMA or PEGMA. In this article, a series of novel xerogels based on NaA and hydrophilic monomer poly(ethylene glycol) methyl ether acrylate (PEGMEA_n), which was synthesized from acryloyl chloride and poly(ethylene glycol) monomethyl ether with three oxyethylene (OE = 9, 16, 45) chain lengths, were prepared by inverse suspension polymerization. The effects of OE chain length in the copolymeric gel on the water absorption behavior and initial absorption rate for the present xerogels were investigated. Results showed that adding a small amount of PEGMEA_n could effectively increase the water absorbency of the gels. In addition, the water absorbency decreased with an increase of the OE chain length in PEGMEA_n. The initial absorption rate for the present copolymeric gels increased with increasing OE chain length in PEGMEA_n and the content of PEGMEA_n in the copolymeric gels. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 927–934, 2006     

Superabsorbent polymeric materials VIII: Swelling behavior of crosslinked poly[sodium acrylate‐co‐trimethyl methacryloyloxyethyl ammonium iodide] in aqueous salt solutions

A series of xerogels based on sodium acrylate (SA), cationic comonomer, trimethyl methacryloyloxyethyl ammonium iodide (TMMAI), and N,N‐methylene‐bis‐acrylamide (NMBA) were prepared by inverse suspension polymerization. The water absorbency and the swelling behavior for these high absorbent polymers in deionized water and various saline solutions were investigated. Results indicated that the water absorbency for the present copolymer gel increased when a small amount of TMMAI monomer was introduced into the SA gel, then decreased with increase in TMMAI content. The water absorbency was 583 g H₂O/g for a gel sample in deionized water containing 2.5 × 10⁻³ molar fraction TMMAI. But a contrary result was observed for initial absorption rate, that is, the initial absorption rates increased with an increase of TMMAI in deionized water and 0.9 wt % NaCl solution. The absorbency in the chloride salt solution decreased with an increase in the ionic strength of the salt solution. Finally, the adsorption of copper ion by these gels was also investigated. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1665–1674, 2001     

Synthesis and characterization of reinforced acrylic‐based superabsorbents crosslinked with divinylbenzene

A series of superabsorbent polymers were synthesized by an inverse suspension polymerization, with potassium persulfate as the initiator, Span60 as the dispersant, and N,N′‐methylene bisacrylamide (BIS) and divinylbenzene (DVB) as multiple crosslinkers. The synthesis conditions, including the amount of dispersant, concentration of crosslinkers, oil‐to‐water phase ratio (O/W) of the polymerization system, total monomer concentration, and acrylamide (AM) content were studied. The results indicated that there were optima for the following properties: BIS crosslinker concentration (0.075 wt %), O/W (3 : 1), total monomer concentration (37.5 wt %), and AM content (5 wt %). In addition, the particle size had a significant influence on the absorption speed, and the absorption speed increased with decreasing particle size. In comparison with the conventional sample crosslinked only by BIS, the superabsorbent with the same particle size but crosslinked by multiple crosslinkers had the higher absorption rate because of surface crosslinking. It also showed that the salt resistance and antihydrolyzing property of the superabsorbent crosslinked by multiple crosslinkers (BIS and DVB) were enhanced, which was also attributed to surface crosslinking by DVB. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1594–1600, 2006     

Synthesis and characterization of functionalized acrylic‐acrylamide‐based superabsorbent gels

We have synthesized series of superabsorbent polymers (SAPs) by solution free radical polymerization of acrylic acid (AA), acrylamide (AM) with different functional monomers (FM). Three functional monomers including zwitterionic monomer [3‐(methacryloylamino) propyl] dimethyl (3‐sulfopropyl) ammonium (MPDSA), cationic monomer (3‐acrylamidopropyl) trimethylammonium chloride (APTAC) and anionic monomer 2‐acrylamidoglycolic acid monohydrate (AGAM) were selected to provide different charged groups on the superabsorbents. The effect of reaction parameters, such as degree of neutralization, content of initiator and crosslinker on the swelling capacity were assessed. The water absorbency of the superabsorbent were characterized in the distilled water, 0.9 wt % NaCl solution and the mixed solution containing 60 mg L^?1 CaCl₂ and 30 mg L^?1 MgCl₂, respectively. In addition, the swelling rate and water retention capacity in the soil were also investigated. Finally, the mechanism of different absorbency induced by the variety kinds of functional monomers was studied by XPS and FTIR, and tentative interpretation was presented as well. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

复配成孔剂对高吸水树脂吸液性能的影响

以丙烯酰胺(AM)、丙烯酸(AA)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)为单体,过硫酸铵为引发剂,N,N-亚甲基双丙烯酰胺为交联剂,山梨醇酐单硬脂酸酯为分散剂,碳酸氢钠与丙酮为复配成孔剂,采用反相悬浮聚合法制备了AA/AM/AMPS多孔型高吸水树脂,并研究了成孔剂种类、复配成孔剂配比、水与环己烷质量比(简称水油比)、中和度、交联剂用量对高吸水树脂吸液性能的影响。结果表明:在水油比为1.0∶2.5,中和度为73%,交联剂用量为0.3%(w),碳酸氢钠与丙酮质量比为1.0∶1.5时,高吸水树脂的吸水倍率和吸盐倍率达到最高,分别为1732.5,142.9 g/g,且具有较好的保水性能。     

高吸水性树脂的合成研究

采用反相悬浮聚合法 ,运用两种不同的交联剂分阶段聚合 ,合成核壳型高吸水树脂。研究了反应温度、丙烯酸中和度、分散剂、交联剂及核壳比对吸水剂吸水性能的影响     

Preparation and water absorbency of a novel poly(acrylate‐co‐acrylamide)/vermiculite superabsorbent composite

A novel poly(acrylate‐co‐acrylamide)/expanded vermiculite (EVMT) superabsorbent composite was synthesized by aqueous solution polymerization method. The water absorbency of the superabsorbent composite still reaches 850 g/g when 50 wt % EVMT is added, which is significant in decreasing the production cost of the superabsorbent composites. By controlling the molar ratio of acrylic acid monomer and acrylamide monomer, and neutralization degree of acrylic acid, the hydrophilic groups on the composite can be adjusted, and it is found that the collaborative absorbent effect of ? CONH₂, ? COOK, and ? COOH groups is superior to that of single ? CONH₂, ? COOK, or ? COOH group. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 735–739, 2007     

Superabsorbent polymeric materials IX: Effect of cationic structure on swelling behavior of crosslinked poly(sodium acrylate‐co‐cationic monomers) in aqueous salt solutions

Two series of xerogels based on sodium acrylate (SA), trimethyl methacrylamidopropyl ammonium iodide (TMMAAI), trimethyl methacryloyloxyethyl ammonium iodide (TMMAI), and N,N′‐methylene‐bis‐acrylamide (NMBA) as a crosslinker were prepared by inverse suspension polymerization. The water absorbency and swelling kinetic behavior for these xerogels in water or various saline solutions were investigated. The results showed that the swelling behaviors of these absorbents are related to their chemical structures, their compositions, and the type of external salt solutions. There would be effective improvement in the water absorbency of these two gel series by copolymerizing SA with a small amount of cationic monomer (TMMAAI or TMMAI). The initial absorption rates in deionized water were found to be faster for TM series gels than for TA series gels. The two series of superabsorbents had a tendency to absorb water in dilute nitrate aqueous solutions in the order: Fe³⁺, Ni²⁺, Ca²⁺, Cu²⁺, and Na⁺ for Fe(NO₃)₃, Ni(NO₃)₂, Ca(NO₃)₂, Cu(NO₃)₂, and NaNO₃ aqueous solution, respectively. The absorbency and initial absorption rate for these gels were related to the gel compositions and salt concentrations. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1827–1837, 2001     

辐射法合成高强吸水剂交联聚丙烯酸钠

利用^60Co辐照引发丙烯酸钠聚合,制得高强吸水剂交联聚丙烯酸钠。研究了单体浓度,中和度．交联剂,辐照剂量等因素对交联聚丙烯酸钠吸水性的影响。结果表明,辐射剂量为20kGy,中和度为70％。单体浓度为16．7％时．交联聚丙烯酸钠具有较高的吸水率,吸生理盐水(0．9％NaCl水溶液)可达128倍．吸自来水可达干重的252倍,吸去离子水可达干重的2096倍。     

Synthesis and properties of a poly(sodium acrylate) bioadhesive nanocomposite

Poly(sodium acrylate) (PNaA) based nanocomposites were synthesized using different nanosilver loadings via redox solution polymerization at room temperature and under full exposure to the atmosphere. The nanocomposites exhibited increasing antibacterial activity with increased nanosilver content. Biocompatibility was determined using an MTT assay; no significant cytotoxicity was observed at the examined nanosilver loadings. Adhesion was measured using a tensile test and the stress versus strain curve showed an acceptable stress development in the model tissue using bioadhesive containing 2 wt% nanosilver. Introducing a second, more degradable polymer to the system as an interpenetrating polymer network enabled tuning the bioadhesive degradation rate.     

Novel degradable superabsorbent materials of silicate/acrylic‐based polymer hybrids

Novel superabsorbent materials, inorganic–organic hybrids, were synthesized by polymerizing acrylic acid or acrylamide with sodium silicate without any other crosslinking agent. The crosslinking bonds of Si? O? C form through the reaction of carboxyl groups with silanol groups (Si? OH) existing in reaction system. Results of FTIR, swelling, and degrading experiments show that the crosslinking degree increased as the mol ratio of silicate increased in a certain range. The hybrids possess the properties of high absorbency and high absorption rate in both distilled water and normal saline solution. Because of the hydrolysis of Si? O? C bonds in aqueous solution, the hybrid hydrogels can degrade in days, and maybe beneficial to environment protection. This property is quite different from those superabsorbent polymer crosslinked with organic crosslinking agent. By monitoring the temperature of the reaction system, sodium silicate was also found to facilitate the trommsdorff effect in polymerization process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 936–940, 2004     

聚丙烯酸类超强吸水剂的合成与性能研究

以丙烯酸烯丙酯作为交联剂、丙烯酸(AA)为单体、过硫酸钾(KPS)为引发剂,采用溶液聚合法合成了一种聚丙烯酸类超强吸水剂。研究了合成条件对吸水性能的影响:当ρ(丙烯酸烯丙酯)=0 594g/L,ρ(KPS)=0 178g/L,单体中和度x(丙烯酸钠)=90%,c(丙烯酸钠)=4 17mol/L,聚合温度为60℃时,制得的聚合物每克吸去离子水最高达到1360mL,吸盐水(生理盐水)162mL。所得的聚合物具有良好的吸水可逆性,30min的吸水量可以达到饱和吸水量的90%。制得聚合物的热重分析表明,未吸水的该聚合物在350℃开始分解。聚合物吸水前后XRD测试结果显示:吸水前聚合物结构基本无规整性,吸水后膨胀使主链展开,结构趋于规整。     

反相悬浮聚合丙烯酸钠树脂合成方法的研究

用反相悬浮聚合的方法合成了聚丙烯酸钠吸水树脂，通过加入十二烷基磷酸酯作保护剂，使树脂颗粒的烘干和粉碎更容易，并选择了最佳分散介质和油水比。     

丙烯酸钠的聚合及吸水性能研究

以正己烷为连续相,司班80为分散剂,N,N‘-亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发剂,采用反相悬浮聚合法合成了高吸水性聚丙烯酸钠树脂。通过调整分散剂、引发剂、交联剂的用量,制备了几种高吸水性的树脂。在制得的高吸水性聚丙烯酸钠树脂中,性能最好的树脂吸去离子水为550mL／g,吸自来水为170mL／g,吸0．9％NaCl溶液60mL／g。     

Water‐soluble copolymers. II. Inverse emulsion terpolymerization of acrylamide,sodium acrylate,and acryloyloxyethyl trimethylammonium chloride

Inverse emulsion terpolymerization of acrylamide, sodium acrylate, and acryloyloxyethyl trimethylammonium chloride was investigated. Aqueous monomer solutions were emulsified in diesel oil with a blend of two surfactants (SPAN80 and TWEEN80) using 2,2′‐azobis(2‐amidinopropen)‐dihydrochloride as the initiator. The effects of temperature, initiator concentration, monomer concentration and composition, and emulsifier content on the polymerization conversion and the polymer intrinsic viscosity were examined. Polymer intrinsic viscosity increased with a decreasing concentration of initiator and an increasing concentration of monomer. The sizes of the latex particles of the terpolymer emulsions were observed with a scanning electron microscope, and the structure of the terpolymer was identified by FTIR spectroscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1381–1385, 2006