Polymerization Of Acrylamide In Solution Research Articles

Dual-Cross-Linked Chitosan-Based Antibacterial Hydrogels with Tough and Adhesive Properties for Wound Dressing.

Biocompatible chitosan-based hydrogels have attracted extensive attention in wound dressing due to their human skin-like tissue characteristics. However, it is a crucial challenge to fabricate chitosan-based hydrogels with versatile properties, including flexibility, stretchability, adhesivity, and antibacterial activity. In this work, a kind of chitosan-based hydrogels with integrated functionalities are facilely prepared by solution polymerization of acrylamide (AAm) and sodium p-styrene sulfonate (SS) in the presence of quaternized carboxymethyl chitosan (QCMCS). Due to the dual cross-linking between QCMCS and P(AAm-co-SS), the optimized QCMCS/P(AAm-co-SS) hydrogel exhibits tough mechanical properties (0.767MPa tensile stress and 1100% fracture strain) and moderate tissue adhesion (11.4kPa). Moreover, biological evaluation in vitro illustrated that as-prepared hydrogel possesses satisfactory biocompatibility, hemocompatibility, and excellent antibacterial ability (against S. aureus and E. coli are 98.8% and 97.3%, respectively). Then, the hydrogels are tested in a rat model for bacterial infection incision in vivo, and the results show that they can significantly accelerate epidermal regeneration and wound closure. This is due to their ability to reduce the inflammatory response, promote the formation of collagen deposition and granulation tissue. The proposed chitosan-based antibacterial hydrogels have the potential to be a highly effective wound dressing in clinical wound healing.

High-strength amphoteric hydrogel that can realize self-repairing of cement microcracks triggered by CO2 gas

During the completion of a natural gas well, the annular gas migration of the cement paste significantly damages the cement quality. Thus, the cement with self-repairing property has great significance in oil well applications. In this work, chemically cross-linked hydrogels were synthesized by the solution polymerization of acrylamide, acrylic acid, and 2-(dimethylamino)ethyl methacrylate (DMAEMA) with NMBA as cross linker to plug the CO2-triggered microcracks in the cement paste. The mechanical strength of the hydrogel (Cu-PMAD) was significantly enhanced by complexation between Cu2+ and the carboxyl group of the hydrogel network. As a self-healing plugging material, Cu-PMAD hydrogel powder was mixed with cement to prepare self-repairing cement slurry. The amphoteric structure of hydrogel was triggered by CO2 due to the DMAEMA unit of the hydrogel was protonated, and the hydrogel can swell further by the anti-polyelectrolyte effect under CO2 of nature gas and formation salt-bearing fluid. The good swelling ability and mechanical properties endowed the Cu-PMAD hydrogel with excellent plugging ability for cement microcracks triggered by CO2.

Evaluation of removal of acid dyes using PAM-FeSO4 hybrid polymer as flocculant

PurposeIn this study, the removal of a series of acid dyes by hybrid polymer adsorbent was investigated. Textile industry wastewater is mainly consisted of suspended solid particles and organic compounds with complex and nondecomposable structures. Treatment of such wastewaters has received much attention by researchers because of high water consumption and the presence of various chemical compounds, especially dyes. The use of polymers has recently attracted much attention for the treatment of textile wastewaters. According to the literature, hybrid polymers are highly capable of adsorbing dyes. In this research work, polyacrylamide/iron sulfate (PAM-FeSO4) hybrid polymer was successfully synthesized through solution polymerization of acrylamide with ammonium persulfate and sodium thiosulfate and gradual addition of iron sulfate. The hybrid polymeric adsorbent was then used for removing acidic dyes with different chemical structures.Design/methodology/approachThe effects of various experimental conditions and parameters, such as initial concentrations of dye and adsorbent, on the adsorption capacity of the adsorbent were investigated. The dye concentration was measured by an UV–vis spectrophotometer. The adsorption equilibrium was studied by plotting adsorption isotherms. The experimental data was fitted to Langmuir and Freundlich isotherms.FindingsThe adsorption experiments indicated that the PAM-FeSO4 hybrid polymer has a high adsorption capacity (117.64 mg g−1 for the Orange ІІ and 80.64 mg g−1 for the Sunset Yellow [SY]) when 80 mg of adsorbent was immersed in the dye solution (1 g L−1) with a pH of 11 at 25°C. The analysis of the equilibrium isotherms using the Langmuir and Freundlich isotherms indicated that the Langmuir model fit well to the experimental data.Originality/valueTo the best of the authors’ knowledge, this study is original. The removal of acid dyes such as Sunset Yellow and Methyl Orange using PAM-FeSO4 hybrid polymer as flocculant was done for the first time.

Reversible-deactivation radical polymerizations of acrylamide mediated by cobalt complexes supported by amino-bis(phenolate) ligands

Reversible-deactivation radical polymerizations (RDRP) of acrylamide (AM) was carried out via dispersion polymerization mediated by cobalt complexes in alcohol/water and initiated by azobisisobutyronitrile (AIBN) at 65 °C. Well-defined polyacrylamide (PAM) uniform spherical particles with predetermined molecular weight and relatively narrow dispersity (Đ = 1.24–1.53) were obtained under mild thermal conditions based on one polymer chain per cobalt complex demonstrate the living characters of the polymerization process. The living character was demonstrated by the linear fit with different feeding ratios of AM and cobalt complex, as well as a linear increase in the number- average molecular weight observed with the monomer conversion. It is worth pointing out that the high conversion of AM (>90%) was obtained with formation of well-controlled PAM, relative to the cobalt porphyrin (The conversion of AM reached 40%) in dispersion polymerization condition. The effects of the volume ratio of alcohol and water on the morphology of the spherical particles were investigated. There were increasing trends in the particle size with the increasing volume ratio of alcohol and water. Solution polymerization of acrylamide was also studied in the same condition. Linear fit with different feeding ratios of AM and cobalt complex were obtained.

Fabrication of bilayered attapulgite for solar steam generation with high conversion efficiency

Solar steam generation has been attracting wide attention for boosting the evolution of solar-energy-harvesting technology. Here, we demonstrate the fabrication of a novel bilayer photothermal material based on attapulgite/poly acrylamide composite (APAC), which was prepared by the solution polymerization of acrylamide (AM) in the presence of attapulgite using N, N′-Methylene bisacrylamide (MBA) as a crosslinker, for efficient solar steam generation. The APAC shows better thermal stability with a decomposition temperature of 250 °C, good mechanical property with a compress strength of up to 125 KPa at 75% strain and a low apparent density (0.0191 g·cm−3) with abundant porosity accompanying with a low thermal conductivity (0.07 W m−1 K−1). To enhance the light absorption of APAC, a thin carbon layer was created on the surface of APAC via a facile flame treatment. Under our conditions, the bilayered APAC shows a high vapor rate of 1.2 kg m−2 h−1 under 1 sun illumination, equal to 85% solar-to-vapor efficiency. With the merits of cost-efficient, scalable manufacture, high solar energy conversion efficiency, the APAC may hold the great potential as high-performance photothermal materials for solar energy generation.

Guar Gum-Grafted Terpolymer Hydrogels for Ligand-Selective Individual and Synergistic Adsorption: Effect of Comonomer Composition.

Grafting of guar gum (GG) and in situ strategic attachment of acrylamidosodiumpropanoate (ASP) via solution polymerization of acrylamide (AM) and sodium acrylate (SA) resulted in the synthesis of a sustainable GG-g-(AM-co-SA-co-ASP)/GGAMSAASP interpenetrating polymer network (IPN)-based smart superadsorbent with excellent physicochemical properties and reusability, through systematic optimization by response surface methodology (RSM) for removal of methyl violet (MV) and/or Hg(II). The relative effects of SA/AM ratios, in situ allocation of ASP, grafting of GG into the AMSAASP terpolymer, ligand-selective superadsorption mechanism, and relative microstructural changes in individually/synergistically-adsorbed MV–/Hg(II)–/Hg(II)–MV–GGAMSAASPs were determined by extensive analyses using Fourier transform infrared (FTIR), proton nuclear magnetic resonance, ultraviolet–visible (UV–vis), and O 1s-/N 1s-/C 1s-/Hg 4f7/2,5/2-X-ray photoelectron spectroscopies, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive spectroscopy and were supported by % gel content, pHPZC, and % graft ratio. The ionic/covalent-bonding, monodentate, bidentate bridging, and bidentate chelating coordination between GGAMSAASPs and Hg(II), and MV+–Hg(II) bonding were rationalized by FTIR, UV–vis, fitment of kinetics data to the pseudo-second-order model, and thermodynamic parameters. The maximum adsorption capacities of 49.12 and 53.28 mg g–1 were determined for Hg(II) and MV, respectively, under optimized conditions.

Study on properties of hydrophobic associating polymer as drag reduction agent for fracturing fluid

In the paper, the hydrophobic associating polymer ACS-210 was prepared by solution polymerization of acrylamide, acrylic acid, salt-resisting monomer and hydrophobic monomer. Chemical structure and properties of the polymer was characterized by FTIR, TGA and XRD. The rheological property of ACS-210 solution was investigated by rheometer. The frictional resistance of the ACS-210 solutions at different application condition was examined using friction testing system. Results showed that the thermal stability of polymer ACS-210 increases and crystallinity of ACS-210 declines after incorporating of hydrophobic monomer. The viscosity of ACS-210 solution of different concentration decreased with prolonging the shearing time and the retention rate of viscosity is relatively high after long shearing time. The relation curve between the viscosity of polymer solution and shear rate followed the power law model. When the concentration of ACS-210 aqueous solution was less than the critical associating concentrations, storage modulus G’ is less than loss modulus G”, the association was weaker between the molecular chains, and the effective spatial structure did not form. After increasing the concentration of the polymer solution, G’ is more than G”, the degree of association of polymer is stronger. The synthesized polymer has favorable drag reduction effect. The molecular weight is not the only factor to determine drag reduction efficiency. The hydrophobic association can also improve the drag reduction efficiency.

A novel polyacrylamide‐based superabsorbent with temperature switch for steam breakthrough blockage

ABSTRACTA novel high‐temperature resistant superabsorbent polymer (SAP) with a temperature switch to control its water absorbency was prepared through solution polymerization of acrylamide (AM), using N,N‐methylenebisacrylamide (NMBA) and tetraallylammonium chloride (TAAC) as crosslinking agents. The SAPs were structurally characterized by Fourier transform infrared (FTIR) spectroscopy and energy dispersive X‐ray spectroscopy (EDX). The factors that influence the water absorbency such as total crosslinker concentration, molar ratio of NMBA to TAAC and temperature were investigated. The SAP with optimized crosslinker concentration showed a swelling ratio less than 10 g/g at 25°C, and drastically enhanced water absorption capacity (190 g/g) at 300°C. The water absorption characteristics can be tuned by varying the temperature. Swelling experimental results combined with crosslinking density study and morphology observation by scanning electron microscopy (SEM) clearly demonstrated that the hydrolysis of amide bonds on NMBA played a critical role in creating these previously unreported SAPs, and that the use of TAAC with an appropriate amount rendered the SAPs high‐temperature resistance. This kind of SAPs has high application potentials as plugging material for steam breakthrough and channeling in heavy oil reservoirs. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42067.

Preparation and swelling behaviors of a high temperature resistant superabsorbent using tetraallylammonium chloride as crosslinking agent

A new high temperature resistant superabsorbent was synthesized through solution polymerization of acrylamide (AM) and partially neutralized acrylic acid (AA), using tetraallylammonium chloride (TAAC) as crosslinker, ammonium persulfate (APS) as initiator. Parameters that influence water absorbency of the superabsorbent at 25°C and 200°C such as molar ratios of AM to AA, TAAC to AA, APS to AA and neutralization degree, were investigated. Swelling behaviors of superabsorbent prepared at the optimum conditions in different pH and saline solutions were studied. The swelling ratios of superabsorbent in distilled water and 1wt% NaCl solution at 250°C reach 287g/g and 69g/g, respectively.

三次采油耐温抗盐聚合物的合成与评价

The copolymer (AM-AANa-AMPSNa) was synthesized by solution polymerization of acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and sodium hydroxide (NaOH) with (NH 4 ) 2 S 2 O 8 , Na 2 SO 3 and N(CH 3 ) 2 CON(CH 3 ) 2 as initiator. The effects of initiator content, monomer concentration, pH and reaction temperature on the viscosity-average molecular weight were investigated, and the optimal conditions were obtained: the initiator content of 0.035%, the monomer concentration of 25%, pH 7, reaction temperature of 0 ℃. The structure of copolymer was characterized by IR spectrum and 13 C NMR spectroscopy. In the performance experiments, physicochemical properties, viscoelasticity, injection, oil displacement were evaluated. Results indicated that the copolymer (AM-AANa- AMPSNa) demonstrated superior temperature-resistance and salt-resistance compared to higher molecular weight partially hydrolyzed polyacrylamide (HPAM). It was found that the viscosity-average molecular weight of the copolymer could reach 3.0 × 10 7 , and the viscosity of the copolymer solution, obtained with Shengli III salt water could reach 17.7 mPa s at the concentration of 1500 mg/L at 85 ℃. The simulative oil displacement signified that copolymers (AM-AANa-AMPSNa) could remarkably enhance 15.8% of oil recovery ratio, especially after water flooding at the oil recovery ratio of 51.8%. These features indicated that the copolymers had a great potential application for tertiary oil recovery, especially in high-temperature and high-mineralization oil fields.

Superparamagnetic Core-Shell Polymeric Nanocomposites for Efficient Removal of Methylene Blue from Aqueous Solutions

Ultrafine well-dispersed Fe3O4 magnetic nanoparticles (NPs) were directly prepared in an aqueous solution using controlled co-precipitation method. The Fe3O4-poly(acrylamide-co-sodium acrylate) core-shell magnetic nanogels are prepared by solution polymerization of acrylamide (AM) and sodium acrylate (AA-Na) monomers in the presence of Fe3O4 NPs, N,N'-methylenebisacrylamide (MBA) as a cross-linker, N,N,N',N'-tetramethylethylenediamine and potassium peroxydisulphate (KPS) as the redox initiator system. The novel Fe3O4-poly(acrylamide-co- sodium acrylate) core-shell magnetic nanocomposite hydrogels are prepared by in situ free radical co-polymerization of AM and AA-Na in an aqueous dispersion of nanogel particles using MBA as the cross-linker and KPS as the initiator. The as-prepared nanocomposite hydrogels are characterized by Fourier transform infrared spectroscopy spectra, X-ray powder diffraction and transmission electron microscopic measurements. The mean particle size of the synthesized magnetite (Fe3O4) NPs was approximately 8 nm. The diameter of the stabilized polymer-coated Fe3O4 nanogels is approximately 11 nm. The surface morphology of the nanocomposites has been studied by scanning electron microscopy and atomic force microscopy. The Fe3O4-poly(acrylamide-co-sodium acrylate) nanocomposites have been extensively investigated for the removal of basic dyes from aqueous solutions. Results of batch experiments showed that these adsorbents exhibited high sorption capacities towards methylene blue (MB). Experimental data were analyzed using first-order kinetics, pseudo-second-order kinetics and intra-particle diffusion models. The kinetics followed a pseudo-second-order equation. Equilibrium isotherm data were analyzed according to Langmuir and Freundlich equations. The thermodynamic parameters for the adsorption of MB onto the nanocomposite hydrogels were also calculated. Regeneration of nanocomposite adsorbents can be easily achieved.

Response Surface Methodology (RSM) for Wastewater Flocculation by a Novel (AlCl<sub>3</sub>-PAM) Hybrid Polymer

In this study, a novel aluminum chloride-ploy(acrylamide) hybrid polymer has been synthesized by free radical solution polymerization of acrylamide (AM) onto aluminum chloride (AlCl3) in the presence of ammonium persulphate and sodium hydrogen sulphite as polymerization’s initiators. On the other hand, the structure of hybrid polymer (AlCl3-PAM) has been characterized by Fourier transform infrared spectroscopy (FTIR). The central composite design (CCD) and response surface methodology (RSM) have been applied in the flocculation process of wastewater treatment to achieve maximum removal efficiencies of total suspended solids (TSS), turbidity , and chemical oxygen demined (COD), as the other objectives of this study. The operating variables in this experiment were new hybrid polymer dose and wastewater pH. The maximum conditions have been found to be wastewater pH 7, and hybrid polymer dose 100 mg/l. Under these optimal conditions, the removal of turbidity, TSS, and COD in the effluent have been reached to 98.2%, 99.1%, and 90.6% respectively. According to these results, domestic wastewater treatment using (AlCl3-PAM) has proved to be an effective alternative in the administration of COD, TSS, and turbidity problems of municipality wastewater.

Novel carrageenan-based hydrogel nanocomposites containing laponite RD and their application to remove cationic dye

Novel hydrogel nanocomposites were synthesized by solution polymerization of acrylamide in the presence of carrageenan biopolymer and laponite RD clay. Laponite was used as an inorganic cross-linker. Ammonium persulfate was applied as an initiator. The structure and morphology of the nanocomposites were investigated using XRD, scanning electron microscopy, and transition electron microscopy techniques. The influence of both laponite nanoclay and the carrageenan content on the swelling degree of nanocomposites was studied and it was found that all nanocomposites containing carrageenan component have a high swelling degree compared to a nanocomposite without carrageenan. The obtained nanocomposites were examined to remove a cationic crystal violet (CV) dye from water. The effect of carrageenan and clay contents on the speed of dye adsorption revealed that while the rate of dye adsorption is enhanced by increasing the clay content, it was depressed as the carrageenan content increased in nanocomposite composition. The results showed that the pseudo-second-order adsorption kinetic was predominant in adsorption of CV onto nanocomposites. The experimental equilibrated adsorption capacity of nanocomposites was analyzed using Freundlich and Langmuir isotherm models. The results indicated that the experimental data fit the Langmuir isotherm best. Maximum adsorption capacity was obtained for carrageenan-free nanocomposite with 79.8 mg g−1 of adsorbed CV onto nanocomposite.

Composite sorbent for attrition minimization

Attrition is erosion by friction, i.e., wearing down of particles by friction due to water. Powdery materials such as titanium dioxide (TiO2), a well known sorbent, suffers from attrition loss during metal ion recovery, mainly during regeneration of TiO2 for reuse. To minimize the inorganic sorbent (TiO2) loss, inorganic–organic composite (hybrid) sorbent was prepared from a radical initiated solution polymerization of acrylamide and freshly prepared titanium dioxide. Uranium uptake has been compared with titanium dioxide (freshly prepared), TiO2–polymer composite and virgin polymer. The potential of this composite sorbents for the uranium recovery was ascertained.

Competitive adsorption of Hg 2+, Pb 2+ and Co 2+ ions on polyacrylamide/attapulgite

In the present study, the competitive adsorption characteristics of binary and ternary heavy metal ions Hg 2+, Pb 2+ and Co 2+ on polyacrylamide/attapulgite (PAM/ATP) were investigated in batch systems. PAM/ATP was prepared by the solution polymerization of acrylamide (AM) onto γ-methacryloxypropyl trimethoxy silane (KH-570) modified attapulgite (ATP) and characterized by the technique of X-ray photoelectron spectroscopy (XPS). Equilibrium and kinetic adsorption data showed that PAM/ATP displays a high selectivity towards one metal in a two-component or a three-component system with an affinity order of Hg 2+ > Pb 2+ > Co 2+. The equilibrium behaviors of heavy metal species with stronger affinity toward PAM/ATP can be described by the Langmuir equation while the adsorption kinetics of the metals can be well fitted to a pseudo-second-order kinetic model. Desorption was performed using hot acetic acid, and the regenerated adsorbents could be reused with little loss of adsorption capacity.

Preparation and characterization of polyacrylamide /palygorskite

Polyacrylamide/palygorskite(PAM/PA) as prepared by solution polymerization of acrylamide (AM) on the γ-methacryloxypropyl trimethoxy-silane (KH-570) modified palygorskite (PA). The influence of monomer concentration, polymerization time, initiator concentration and polymerization temperature on mercury adsorption of PAM/PA was investigated. The maximum adsorption capacity was 135.5 mg/g at optimum polymerization conditions. PAM/PA was characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD).

Adsorption of Hg 2+ from aqueous solution onto polyacrylamide/attapulgite

Polyacrylamide/attapulgite (PAM/ATP) was prepared by the solution polymerization of acrylamide (AM) onto γ-methacryloxypropyl trimethoxy silane (KH-570)-modified attapulgite (ATP). PAM/ATP was characterized using Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The effects of contact time, adsorbent dosage, and pH of the initial solution on the adsorption capacities for Hg 2+ were investigated. The adsorption process was rapid; 88% of adsorption occurred within 5 min and equilibrium was achieved at around 40 min. The equilibrium data fitted the Langmuir sorption isotherms well, and the maximum adsorption capacity of Hg 2+ onto PAM/ATP was found to be 192.5 mg g −1. The adsorption kinetics of PAM/ATP fitted a pseudo-second-order kinetic model. Our results suggest that chemisorption processes could be the rate-limiting steps in the process of Hg 2+ adsorption. Hg 2+ adsorbed onto PAM/ATP could be effectively desorbed in hot acetic acid solution, and the adsorption capacity of the regenerated adsorbents could still be maintained at 95% by the sixth cycle.

Ceric ion‐induced graft copolymerization of acrylamide on cationic guar gum at low temperature

AbstractThe solution polymerization of acrylamide (AM) on cationic guar gum (CGG) under nitrogen atmosphere using ceric ammonium sulfate (CAS) as the initiator has been realized. The effects of monomer concentration and reaction temperature on grafting conversion, grafting ratio, and grafting efficiency (GE) have been studied. The optimal conditions such as 1.3 mol of AM monomer and 2.2 × 10−4 mol of CAS have been adopted to produce grafted copolymer (CGG1‐g‐PAM) of high GE of more than 95% at 10°C. The rates of polymerization (Rp) and rates of graft copolymerization (Rg) are enhanced with increase in temperature (<35°C).The Rp is enhanced from 0.43 × 10−4 mol L−1 s−1 for GG‐g‐PAM to 2.53 × 10−4 mol L−1 s−1 for CGG1‐g‐PAM (CGG1, degree of substitute (DS) = 0.007), and Rg from 0.42 × 10−4 to 2.00 × 10−4 mol L−1 s−1 at 10°C. The apparent activation energy is decreased from 32.27 kJ mol−1 for GG‐g‐PAM to 8.09 kJ mol−1 for CGG1‐g‐PAM, which indicates CGG has higher reactivity than unmodified GG ranging from 10 to 50°C. Increase of DS of CGG will lead to slow improvement of the polymerization rates and a hypothetical mechanism is put forward. The grafted copolymer has been characterized by infrared spectroscopy, thermal analysis, and scanning electron microscopy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3715–3722, 2007

Kinetic study of radical polymerization. III. Solution polymerization of acrylamide by 1H‐NMR

AbstractSolution and radical polymerization of acrylamide in the presence of potassium persulfate in D2O was investigated up to high conversion by high‐field 1H‐NMR spectroscopy. The kinetics of reaction was studied according to the data obtained from the corresponding spectra at various times during the polymerization reaction progress. Processing of the data led us to derive the rate equation of this polymerization reaction and determine the reaction order of each component in the rate equation. The order, with respect to initiator, was consistent with the classical kinetic rate equation (0.45), whereas the order with respect to monomer was greater than unity (1.49). The effect of temperature on the polymerization rate was also investigated and the activation energy of 48.4 kJ mol−1 was obtained over the temperature range of 60–75°C. Also some mechanistic studies were discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2007–2013, 2004

Solution polymerization of acrylamide using potassium persulfate as an initiator: kinetic studies, temperature and pH dependence

The kinetics of the radical polymerization of acrylamide in aqueous solution using potassium persulfate as initiator has been investigated by the gravimetric technique. Up to 94% conversion was obtained. The rate of polymerization was governed by the expression at 55°C R po =k [ K 2 S 2 O 8] 0.5[ M] 0 1.26 The order with respect to initiator was consistent with the classical kinetic rate equation, while the order with respect to monomer was greater than unity. The effects of temperature and pH on the polymerization rate were also investigated. An overall activation energy of 45.1±0.1 kJ/mol was obtained over the temperature range 35–55°C. It was found that the rate of conversion increased with increasing polymerization temperature, while the polymerization rate was insensitive to the change of pH value when monomer and initiator concentrations, and temperature were all kept constant.