Synthesis and water absorbency of the copolymer of acrylamide with anionic monomers

A series of novel copolymer superabsorbents based on acrylamide, sodium allylsulfonate, sodium acrylate, and N,N′-methylenebisacrylamide were prepared by copolymerization. The resulting superabsorbents have a fast swelling rate. The experimental results show that absorbency increases to a maximum as the cross-linking increases, but an excess of cross-linking leads to a swelling decrease. Their water retention was observed at pressures of 1–10 kg/cm² and temperatures of 60 and 100°C, respectively. The water retention of soil has been enhanced by using the poly(acrylamide–sodium allysulfonate–sodium acrylate) superabsorbent; its use for bean growth was also investigated. © 1994 John Wiley & Sons, Inc.     

Synthesis,swelling capacity,and texture of polymers from monomers of sulfonic acid and acrylamide

The monomers 2‐acrylamido‐2‐methyl‐propanosulfonic acid and acrylamide, and methyleno‐bisacrylamide (BA) whenever a crosslinker was added, were selected for the synthesis of superabsorbent polymers. Texture was observed by scanning electronic microscopy, and specific gravity and swelling were measured. The influence of synthesis conditions—polymerization technique, reaction medium pH, and BA addition—on the texture of the synthesized polymer and its influence on polymer characteristics were assessed. The tests showed that the pores' sizes and distribution in the polymer depend on the polymerization conditions. Swelling rate of the polymers, namely from inverse emulsion technique, with BA and at pH 9, is remarkably high, suiting applications. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Synthesis and physicochemical properties of graft copolymer of corn starch and acrylamide

Graft copolymerization of corn starch with acrylamide using ceric ammonium sulphate/citric acid initiation system has been studied under nitrogen atmosphere in aqueous medium. The grafting parameters are favored by increasing monomer concentration and reaction time but are affected by higher concentration of initiator and high temperature. The optimum conditions established for grafting were as follows: the concentration of initiator, 0.003 mol/L; the concentration of citric acid, 0.03 mol/L; monomer/starch, 1:1 feed ratio (w/w); reaction time, 3.0 h; and temperature, 35°C. The extent of grafting was examined by Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy. Both swelling power and solubility increased with the increase in temperature. Graft copolymerization increased swelling power and reduced solubility. Rapid visco‐analyzer pasting profile was studied. Graft copolymerization of corn starch results in high pasting temperature, high peak viscosity, and setback as compared with native starch. Breakdown was retarded at low percentage grafting (6.60%) but increased at high percentage grafting (60.27%). POLYM. COMPOS. 28:47–56, 2007. © 2007 Society of Plastics Engineers     

自交联阳离子丙烯酰胺共聚物合成及应用

以甲基丙烯酰氧乙基三甲基氯化铵（DMC）作为阳离子单体,甲基丙烯酸缩水甘油酯（GMA）为交联单体,与丙烯酰胺（AM）通过水溶液共聚法,并采用分子量调节剂和活性基团保护剂,本文制备得到自交联阳离子丙烯酰胺共聚物（G-CPAM）。通过傅里叶红外光谱（FTIR）及溶液稳定性测试对G-CPAM的结构和稳定性进行了表征,探讨了DMC及GMA单体用量对G-CPAM的性能及施胶后纸张的物理性能的影响,利用热失重分析仪（TGA）、X射线光电子谱（XPS）以及纸张施胶前后的FTIR测试对G-CPAM的自身交联与纸张性能增强机理进行了研究。结果表明：当DMC用量为质量分数20%,GMA用量为质量分数13%时,制备得可交联环氧阳离子聚丙烯酰胺,此时聚合物溶液平均粒径为176.9nm,黏度为143mPa·s,分子量为63204,且在150℃下稳定存在。 G-CPAM添加量为质量分数1.6%,进行浆内施胶,纸张干、湿抗张指数分别为58.29N·m/g和17.75N·m/g,环压强度指数为11.10N·m/g,撕裂指数为12.41mN·m²/g,纸张物理性能增强明显。     

水溶性微交联丙烯酰胺共聚物的表征与溶液性能

以丙烯酰胺(AM)为主要单体,以2-甲基-2-丙烯酰胺基丙磺酸(AMPS)为增溶单体,以二乙烯基苯(DVB)为交联单体,采用自由基胶束聚合法合成了水溶性微交联共聚物(PADM),研究了AMPS和DVB的反应加量、NaC l浓度、温度及剪切速率对共聚物溶液性能的影响。结果表明,引入DVB使共聚物具有优良的增粘和抗盐能力,DVB摩尔分率为0.7%的0.15 g/dL PADM于45℃在淡水和7.5 g/dL盐水中的表观粘度分别为376.9 mPa.s和155.4 mPa.s。另外,PADM也显示了良好的抗剪切和耐温性能。     

丙烯酸丁酯/苯乙烯/功能单体多元共聚乳液的合成

通过一步加料和滴加引发剂的方法合成了丙烯酸丁酯、苯乙烯和功能单体的多元共聚乳液,对其性能进行了表征。结果表明:在合适的单体配比条件下,可以得到一种较高固含量、低粘度,且具有良好稳定性的共聚乳液。     

Synthesis and swelling behavior of crosslinked copolymers of neutralized maleic anhydride with other monomers

A series of novel copolymer superabsorbents based on maleic anhydride (MLN), acrylamide (AAM), hydroxyethyl methacrylate (HEMA), and N,N′‐methylenebisacrylamide (NMBA) were prepared by inverse‐suspension polymerization. The influence of the reaction parameters on the water absorption was investigated to improve the understanding and to identify the optimum reaction conditions. The water absorbences or swelling behaviors for these absorbents in various salt solutions and various alcohol solutions were studied. The tendency of the absorbency for these absorbents in salt and alcohol solutions is in the order Na⁺ > Ca²⁺ > Al³⁺ for NaCl, CaCl₂, and AlCl₃ aqueous solutions and a glycerol > glycol > methanol > ethanol solution, respectively. This article also explains the IR and SEM characterization of the water‐absorbing copolymers and their practical use in soil for water retention. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 2725–2731, 2003     

Influence of starch granule swelling on graft copolymer composition. A comparison of monomers

Seven monomers, which varied widely in water solubility and ionic charge, were graft polymerized onto both unswollen starch and starch that had been swollen by heating in water to 60°C. Polymerizations were initiated with ferrous ammonium sulfate hexahydrate–hydrogen peroxide and, where applicable, with ceric ammonium nitrate. Graft copolymers were freed of ungrafted homopolymer by solvent extraction and were characterized by weight percentage of synthetic polymer incorporated in the graft copolymer, molecular weight of grafted branches, and grafting frequency. The influence of starch granule swelling on graft copolymer structure varied with the monomer used and could not be predicted on the basis of water solubility of monomer or its resulting polymer. With acrylonitrile and acrylamide, swollen starch gave higher molecular weight and less frequent grafts than unswollen starch. However, methyl methacrylate, N,N-dimethylaminoethyl methacrylate · HNO₃, N-t-butylaminoethyl methacrylate. HNO₃, and 2-hydroxy-3-methacryloyloxypropyltrimethylammonium chloride produced less frequent graft of higher molecular weight when starch was unswollen. With acrylic acid, graft molecular weight was independent of starch granule swelling, although grafting was less frequent when swollen starch was used.     

Synthesis of N,N'-diallylmalonamide and its copolymer gels with acrylic acid and acrylamide

N,N'-diallylmalonamide (DAM) has been prepared via classical aminolysis of diethyl malonate with allylamine. Its structure was confirmed by elementary microanalysis as well as ¹H NMR and FT-IR spectroscopy. The new diallyl monomer is water-soluble and able to copolymerize radically with water-soluble monomers, such as acrylamide and acrylic acid, to give transparent hydrogels by using K₂S₂O₈ as initiator. Homopolymerization of DAM yields clear hydrogels with high swelling ability.     

Thermodynamic correlation of partial and saturation swelling of styrene-acrylonitrile copolymer particles by styrene and acrylonitrile monomers

The possibility of thermodynamic correlation of partial and saturation swelling of styrene-acrylonitrile (SAN) copolymer particles by styrene (St) and acrylonitrile (AN) monomers is investigated. The unknown Flory-Huggins interaction parameters involved in the thermodynamic swelling equations are estimated by fitting the equations to the experimentally observed monomer concentrations. It is shown that the concentration of each monomer in SAN copolymer particles predicted by using the thermodynamic swelling equations with the parameters and constants estimated in this study agrees fairly well with that observed experimentally over a wide range of experimental conditions. The validity and utility of the parameters and constants estimated from saturation swelling are also demonstrated by showing that the experimental results for partial swelling of SAN copolymer particles by AN monomer dissolved in the aqueous phase agree with those predicted by the thermodynamic equation for partial swelling. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 931–939, 1997     

Synthesis of copolymer of acrylamide with sodium vinylsulfonate and its thermal stability in solution

The copolymer of acrylamide and sodium vinylsulfonate (PAMSVS) was synthesized by inverse emulsion polymerization and its thermal stability in aqueous and saline solution was investigated. Four samples with different monomer ratio were prepared and the thermal degradation of these samples in aqueous solutions was carried out at 90 °C, 120 °C and 150 °C, respectively. The variation of apparent viscosity during the degradation was investigated. The results indicate that all three PAMSVS samples have better performance of heat endurance than polyacrylamide. Moreover, the sample, which contains 3.4% (molar ratio) sulfonic groups, has the most excellent property of heat endurance. The salt tolerance test of these samples was carried out at 57 °C in 5 mmol/L CaCl₂, 5 mmol/L MgCl₂ and mineralized water, respectively. The results show that all three PAMSVS samples exhibit better property of Ca²⁺ ion tolerance than PAM and the best one is the sample, which contains 6.5% (molar ratio) sulfonic groups.     

Bismaleimide monomers with amide units: Synthesis and properties

A series of bismaleimide monomers with amide groups were prepared and characterized. Structurally different bismaleimides (with amide units) were synthesized by a reaction between 4‐maleimidobenzoyl chloride and various diamines. The monomers were characterized by infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and elemental analysis. The thermal characterization of the bismaleimides was accomplished with differential scanning calorimetry and dynamic thermogravimetric analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 567–572, 2006     

丙烯酰胺共聚物乳液增稠剂的合成及性能研究

以丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸钠(SAMPS)为聚合单体,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,采用反相乳液聚合法,合成了微交联型丙烯酰胺共聚物乳液。当n(AM)∶n(SAMPS)=3∶2,MBA为单体总质量的0.08%,过硫酸铵为单体总质量的0.03%,异丙醇为单体总质量的0.3%,亚硫酸氢钠为单体总质量的0.06%时,合成产物具有优良的增稠性能和耐电解质性能。测试结果表明,质量分数1%的聚合物水溶液黏度大于1.0×105mPa.s,质量分数1.2%的聚合物水溶液在质量分数0.1%氯化镁和氯化钠存在时的黏度保持率分别为32.76%和24.66%。另外该聚合物乳液的残留丙烯酰胺(2 mg/kg,反相时间(15 s。     

Synthesis and properties of brominate bismaleimide monomers

Brominated bismaleimides were prepared by reacting 3(4)‐maleimidobenzoylchloride with various bisphenols, using chloroform as solvent and triethylamine as acid acceptor. These monomers were characterized by elemental analysis, infrared (IR), and proton nuclear resonance (¹H‐NMR) spectroscopy. Thermal properties of monomers were accomplished by differential scanning calorimetry (DSC) and dynamic thermogravimetric analysis (ATG). The properties of these compounds were compared with those of monomers derived from bisphenol A and bisphenol A chlorinated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3881–3885, 2006     

Synthesis and properties of the copolymer of acrylamide with 2‐acrylamido‐2‐methylpropanesulfonic acid

A cross‐linked copolymer of acrylamide (AM) with 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS) was prepared by solution polymerization. In this reaction, potassium persulfate (PPS) and N,N′‐methylenebisacrylamide (NMBA) were used as initiator and cross‐linker, respectively. This copolymer, poly(acrylamide‐co‐2‐acrylamido‐2‐methylpropanesulfonic acid) (PAMA), can absorb up to 1749 g/g of dry polymer in distilled water and 87 g/g of dry polymer in 0.9 wt % NaCl aqueous solution at room temperature. The PAMA also has excellent performance in absorbing pure alcohols. Its absorbencies in methanol and glycol are about 310 g/g and 660 g/g, respectively. The effects of various salt solutions on the swelling properties were studied systematically, and the relationship between the absorbency and the concentrations of the different salt solutions can be expressed as Q = kcⁿ. Experimental results indicate that the absorbencies were stable at different water temperatures. The swelling rates of the copolymer in distilled water and a water/ethanol mixture (V_water:V_alcohol = 1:1) were also investigated, and the results showed that PAMA could absorb 992 g of distilled water per gram of dry polymer and 739 g of water/ethanol mixture per gram of dry polymer in five minutes. The PAMA has such good water retention at higher temperatures that the swollen gel can retain 71.6 and 49.5% of the maximum absorbency after being heated for 9 hours at 60 and 80 °C, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3481–3487, 2003     

木粉-丙烯酰胺接枝共聚物的制备及其絮凝性能

首先用微波加热法(400 W,90℃)将杉木粉溶解在离子液体氯代1-(2-羟乙基)-3-乙基咪唑([HeEIM]Cl)中,再将溶解体系和丙烯酰胺(AM)原位共混,在过硫酸钾热引发条件下使溶解后的木粉和丙烯酰胺在离子液体介质中接枝共聚,制备了改性絮凝剂AM-g-wood,并用FTIR和XRD对其化学结构和结晶结构进行表征...     

Copolymerization of acrylamide with cationic monomers in solution and inverse-microsuspension

The free radical copolymerization of acrylamide with three of the most commonly used cationic comonomers diallyldimethylammonium chloride, dimethylaminoethylmethacrylate, and dimethylaminoethylacrylate, the latter two quaternized with methyl chloride, was investigated. The polymerizations were carried out with azocyanovaleric acid and potassium persulfate over the temperature range 45–60°C. The copolymer reactivity ratios were determined with the error-in-variables method using residual monomer concentrations, measured by a Nalco HPLC method. This combination of estimation procedure and analytical technique has been found to be superior to any methods used previously for the estimation of reactivity ratios for cationic-acrylamide copolymers.     

Synthesis of amphiphilic block copolymer of acrylamide with styrene using free radical interfacial copolymerization

A novel free radical interfacial copolymerization was proposed and used to prepare the amphiphilic block copolymer of acrylamide (AM) with styrene (S). In this copolymerization, a synthesized new kind of initiator, namely, amphiphilic bifunctional initiator, which has not only a hydrophilic and a hydrophobic group but also two functional groups generating radicals in both ends of its molecule, was used to initiate the interfacial copolymerization. The generated amphiphilic block copolymer was characterized by infrared analysis, differential scanning calorimetry, elemental analysis, and dissolution behavior. The migration of generated copolymer from interface to water phase was discussed. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 443–449, 1998     

Synthesis of tetramethyl-p-silphenylenesiloxanedimethylsiloxane triblock copolymer by employing living anionic polymerization

Dimethylsiloxane-tetramethyl-p-silphenylenesiloxane-dimethylsiloxane (DMS-TMPS-DMS) triblock copolymer was synthesized by employing living anionic polymerization of hexamethylcyclotrisiloxane (D₃). Two synthetic methods were carried out for the polymerization. One of those methods was the anionic polymerization of D₃ initiated at the silanolate anion which was prepared from the terminal hydroxyl group of silanol-terminated TMPS prepolymer by reaction with n-butyllithium (method 1). The other was the coupling reaction of vinyl-terminated TMPS prepolymer with hydrosilyl-terminated DMS prepolymer obtained from the anionic polymerization of D₃ by using diphenylmethylsilanolate anion as initiator (method 2). In method 1, DMS contents of the copolymers ranged from 25.8 to 72.5 wt% and the values agreed with the ratio of D₃ to TMPS prepolymer. The weight-average molecular weights ranged from 1.36×10⁴ to 19.4×10⁴ and were close to the predicted values calculated from the $\text{M}\text{?}{}_{\mathrm{v}}$ of the TMPS prepolymer and the amount of D₃ added. In the case of method 2, weight-average molecular weights ranged from 19.5×10⁴ to 24.2×10⁴. The high molecular weight copolymer could thus be obtained by method 2. Intrinsic viscosity values of the triblock copolymers agreed with calculated values obtained by considering the copolymer as a binary mixture of these homopolymers. Differential scanning calorimetry and thermogravimetry were carried out on the triblock copolymers. The equilibrium melting temperatures of each of the copolymers were very close to that of poly-TMPS (160°C). The glass transition temperature and heat of fusion were decreased as the DMS content was increased. The thermogravimetric curves for the copolymers indicated that the thermal stability of the triblock copolymer was intermediate between the DMS and TMPS homopolymers.     

荧光标记丙烯酸-丙烯酰胺共聚物性能研究

对用4-甲氧基-N-(3-二甲氨基丙基)萘酰亚胺烯丙基氯的季铵盐(4-MNDMAPN-AQ)做荧光标记的丙烯酸/丙烯酰胺(AA/AM)共聚物进行性能评价,研究了pH、氧化剂、常规阻垢剂对荧光强度的影响.实验结果表明:在pH=7～10,常规阻垢剂存在的情况下共聚物的荧光强度稳定,氧化剂作用使其荧光强度减弱,荧光强度与其质量浓度(1～10mg/L)呈良好的线性关系.共聚物具有良好的阻垢性能.