Aqueous dispersion polymerization of acrylamide with quaternary ammonium cationic comonomer

Using aqueous solution of ammonium sulfate as medium, acrylamide (AM) and dimethylaminoethyl methacrylate methyl chloride (DMC) as main raw materials, poly(dimethylaminoethyl methacrylate methyl chloride) (PDMC) as stabilizer and 2,2′‐azobis (2‐amidinopropane) dihydrochloride (V‐50) as initiator, the cationic polyelectrolyte of P(DMC‐AM) was synthesized by aqueous dispersion polymerization. The effects of the major reaction variables on synthesis conditions, product characteristics (particle size and molecular weight), and polymerization rate were investigated. The polymerization was retarded by the presence of the ammonium sulfate. The optimum reaction conditions for obtaining a stable aqueous dispersion were concentrations of 1.8 × 10^?4–7.0 × 10^?4 mol L^?1 for V‐50, 1.5–3.5% for stabilizer, and 23.2–30.0% for salt. The molecular weight of PDMC formed was 1.5 × 10⁵ to 7.0 × 10⁵. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

阳离子聚丙烯酰胺“水包水”乳液的制备研究

在硫酸铵溶液中,以相对分子质量为7.44×10~5～1.21×10~6的聚甲基丙烯酰氧乙基三甲基氯化铵为分散剂,在偶氮二异丁脒盐酸盐引发剂的作用下,通过分散聚合进行了丙烯酰胺和甲基丙烯酰氧乙基三甲基氯化铵的二元共聚。分别探讨了分散剂浓度、无机盐浓度、单体总浓度及其配比、引发剂浓度、反应温度等对分散聚合的影响,找出了各影响因素之间的协同规律,最终确定出最佳的合成条件和体系配比。在上述条件下制备出颗粒分散性较好、流动性较好、稳定性较高、特性黏数及黏均分子量较高的阳离子聚丙烯酰胺＂水包水＂乳液。     

Dispersion polymerization of acrylamide with 2‐acrylamido‐2‐methyl‐1‐propane sulfonate in aqueous solution

The copolymer of acrylamide (AM) and 2‐acrylamido‐2‐methyl‐1‐propane sulfonate (AMPS) was synthesized through the free radical dispersion polymerization in an aqueous solution of ammonium sulfate and in the presence of poly(2‐acrylamido‐2‐methyl‐1‐propane sulfonate) as stabilizer. The average particle size of the copolymer ranged from 1 to 4 μm, and the molecular weight was from 2.0 × 10⁶ to 7.0 × 10⁶ g mol^?1. By analyzing apparent viscosity and particle size, the swelling property of the dispersion copolymer was studied. When the dispersion was diluted with salt water in which the ammonium sulfate concentration kept equal with that of the original dispersion, particle size and particle size distribution of the diluted dispersion changed a little, compared with that of the original dispersion. While diluted with deionized water, particle size and particle size distribution could expand several times. The effects of varying concentrations of the stabilizer, the monomer, the salt and the initiator on particle size, and molecular weight of the copolymer were investigated, respectively. The reaction conditions for preparing stable dispersion were concentrations of 20–28% of the salt, 6–14% of monomers, and 1.8–2.7% of the stabilizer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:2379–2385, 2006     

Methyl methacrylate/2-hydroxyethyl methacrylate/N-hydroxyphenyl maleimide terpolymer as novel photostabilizer for rigid poly(vinyl chloride)

A novel terpolymer based on a polymerizable derivative of 2-hydroxyethyl methacrylate monomer was prepared and evaluated as a photostabilizer for rigid polyvinyl chloride (PVC). The terpolymer, namely, methyl methacrylate/2-hydroxyethyl methacrylate/N-hydroxyphenyl maleimide, MMA/HEMA/N-OHPh-MI, was characterized and its structure was confirmed by FTIR, and ultraviolet–visible (UV–vis) spectroscopy. Gel permeation chromatography was applied to determine the molecular weights of the terpolymer, while its structural morphology was investigated using scanning electron microscopy. The terpolymer was blended with PVC in (2, 4, and 6 wt%) to investigate its photostabilizing potency upon UV irradiation. The results revealed that the stabilizing effect of this terpolymer increased upon increasing the stabilizer concentration and the content of the maleimide (MI) units in the terpolymer. Homogeneity in the structure morphology was attained in case of using the terpolymer at high concentration and high MI content.     

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     

Properties of high‐temperature drilling fluids incorporating disodium itaconate/acrylamide/sodium 2‐acrylamido‐2‐methylpropanesulfonate terpolymers as fluid‐loss reducers

The terpolymer of disodium itaconate (DIA), acrylamide (AM) and sodium 2‐acrylamido‐2‐methyl‐1‐propane sulfonate (SAMPS) was synthesized through free‐radical polymerization, and characterized using FTIR and TGA methods. The IR spectra of DIA‐AM‐SAMPS terpolymer confirmed that there was no olefinic band at 1635–1620 cm^?1, while the TGA results revealed that the terpolymer was of higher thermal stability than the SAMPS homopolymer. The filtrate volume reduced with increase of the terpolymer concentration before or after the aging test. The rheology properties of both fresh‐water mud and salt‐water mud were improved by DIA‐AM‐SAMPS terpolymer, and apparent viscosity (η_a); plastic viscosity (η_b) and yield point (τ₀) of salt‐water mud reached the smallest values at 1.2% of the terpolymer concentration after the aging test. The particle size data demonstrated that only a small change of the clay particle size occurred before and after the aging test at 220°C. This further confirmed the thermal stability of the terpolymer–clay dispersion from another point of view. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 3068–3075, 2002; DOI 10.1002/app.2335     

两性聚丙烯酰胺“水包水”乳液的制备

以丙烯酰胺(AM)和两性单体N,N-二甲基(甲基丙烯酰氧乙基)氨基丙磺酸内盐(DMAPS)为聚合单体,聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)为分散稳定剂,2,2'-偶氮(2-脒基丙烷)二盐酸盐(V-50)为引发剂,在硫酸铵水溶液中通过分散聚合制备两性聚丙烯酰胺(AmPAM)"水包水"乳液。考察了分散剂用量、无机盐用量、单体质量分数及其摩尔比和引发剂用量等对分散聚合的影响,其最佳反应条件为:硫酸铵质量分数22.3%～27.4%、分散剂用量为0.195～0.248 g/g(monomer)、单体摩尔比n(AM)∶n(DMAPS)=9∶1、单体质量分数为14%、引发剂用量为4.5×10-4g/g(monomer)。采用红外光谱(FTIR)和核磁共振氢谱(1HNMR)对聚合物结构进行了表征。     

Kinetic study of emulsion copolymerization of ethyl methacrylate/lauryl methacrylate in propylene glycol,stabilized with poly(ethylene oxide)–block–polystyrene–block–poly(ethylene oxide) triblock copolymer

The kinetics of emulsion copolymerization of ethyl methacrylate (EMA)/lauryl methacrylate (LMA) in propylene glycol is very similar to the emulsion copolymerizations of water‐soluble monomers in water because of the high solubility of EMA/LMA in propylene glycol. The initial rate of polymerization depends only on initiator concentration and is not affected by either monomer concentration or stabilizer concentration. The overall rate of polymerization is only slightly dependent on monomer concentration and stabilizer concentration and is independent of initiator concentration. The final particle number density increases with increasing amount of stabilizer and decreases with increasing monomer concentration. The total surface area increases with stabilizer concentration and is not governed by either initiator concentration or monomer concentration. Homogeneous nucleation is the dominant mechanism of particle nucleation, as shown by the kinetic data on seeded polymerization and monomer partition behavior. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1691–1704, 2001     

Preparation of polyacrylamide aqueous dispersions using poly(sodium acrylic acid) as stabilizer

High‐solids, low‐viscosity, stable polyacrylamide (PAM) aqueous dispersions were prepared by dispersion polymerization of acrylamide in aqueous solution of ammonium sulfate (AS) using poly (sodium acrylic acid) (PAANa) as the stabilizer, ammonium persulfate (APS) or 2,2′‐Azobis (N,N′‐dimethyleneisobutyramidine) dihydrochloride (VA‐044) as the initiator. The molecular weight of the formed PAM, ranged from 710, 000 g/mol to 4,330,000 g/mol, was controlled by the addition of sodium formate as a conventional chain‐transfer agent. The progress of a typical AM dispersion polymerization was monitored with aqueous size exclusion chromatography. The influences of the AS concentration, the poly(sodium acrylic acid) concentration, the initiator type and concentration, the chain‐transfer agent concentration and temperature on the monomer conversion, the dispersion viscosity, the PAM molecular weight and distribution, the particle size and morphology were systematically investigated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and evaluation of homopolymer and terpolymer based on phenyl salicylate as photostabilizers for rigid polyvinylchloride

Terpolymer based on polymerizable derivative of phenyl 5‐methacryloxy methyl salicylate (PMMS) methyl methacrylate (MMA)/2‐hydroxyethyl methacrylate (HEMA)/PMMS was synthesized and evaluated as a photostabilizer for rigid polyvinylchloride (PVC). Evaluation of stabilizing efficiency was carried out by measuring the induction period and the rate of dehydrochlorination by the continuous conductometric determination of the hydrochloric acid (HCl) evolved at 25°C under nitrogen in addition to the extent of discoloration. The results indicated that the stabilizing effect of this terpolymer increased upon increasing the stabilizer concentration and the content of the UV absorber units in the terpolymer. The prepared terpolymer showed higher stabilizing efficiency when compared to the homopolymer of the phenyl salicylate‐based monomer and the commercial UV absorber, phenyl salicylate. Structural morphology of PVC/terpolymer blend was investigated using a scanning electron microscopy (SEM) and thermal properties of the blends were also studied using differential scanning calorimetry (DSC). J. VINYL ADDIT. TECHNOL., 23:70–77, 2017. © 2015 Society of Plastics Engineers     

低电荷密度聚丙烯酰胺水分散体的触变性研究

从流变学的角度,利用静态剪切法对低电荷密度聚丙烯酰胺（D-amPAM）水分散体触变性进行了研究.考察了分散稳定剂浓度、分散稳定剂黏均分子量、共聚物单体浓度以及硫酸铵浓度对D-amPAM体系触变性以及触变强度的影响.结果表明,随分散稳定剂浓度的增加,体系的触变性越来越明显,触变强度越来越大;随分散稳定剂黏均分子量的增加,体系的静态剪切黏度及触变强度先增加后减小;共聚物单体浓度越大,体系的触变形态越稳定单一,触变强度以及静态剪切黏度越大;不同硫酸铵浓度下制取的分散体系触变性及触变强度变化较大.     

Formation of liquid‐crystalline morphologies in dilute solutions of a charged random terpolymer

Formation of micellar morphologies in aqueous solutions of charged random copolymers has been reported in several studies. This paper reports on liquid crystallization of the cationic random acrylic terpolymer i.e., poly[(dimethylaminoethyl methacrylate)‐co‐(methyl methacrylate)‐co‐(butyl methacrylate)] containing no mesogenic groups. The viscometric behaviour of the terpolymer solutions deviated in several ways from ordinary behaviour of polyelectrolytes supporting the possibility of self‐assembly of this cationic random terpolymer in a solvent mixture containing acetone, ethanol and 1‐propanol or each of these solvents separately. The existence of nano‐sized liquid‐crystalline structures was demonstrated using small‐angle X‐ray scattering (SAXS) analysis of the terpolymer solutions. Morphology and sizes of the liquid‐crystalline structures were determined according to the SAXS results and confirmed by dynamic light scattering and atomic force microscopy findings. Liquid crystallization was reasoned on the basis of the existence of a segregated chain microstructure as for polyelectrolytes containing folded parts connected to each other by monomer strings. In a random amphiphilic copolymer or the terpolymer under investigation, the folded parts and strings must be hydrophilic and hydrophobic, respectively. The role of alcohol aggregates should be considered in self‐assembly of the terpolymer chains. The alcohol aggregates can act as physical crosslinkers leading to the formation of more compact liquid‐crystalline structures. The deviations observed in the viscometric behaviour of the terpolymer solutions are suggested as the result of the ability of terpolymer chains to self‐assemble. © 2013 Society of Chemical Industry     

Dispersion polymerization of methyl methacrylate in supercritical carbon dioxide using a silicone‐containing fluoroacrylate stabilizer

Free radical dispersion polymerization of methyl methacrylate (MMA) was carried out in supercritical carbon dioxide (scCO₂) using poly{(heptadecafluorodecyl acrylate)‐co‐3‐[tris(trimethylsilyloxy)silyl]propyl methacrylate} (p(HDFDA‐co‐SiMA)) as stabilizer. Dry, fine powdered spherical poly(methyl methacrylate) (pMMA) particles with well‐defined sizes were produced. The resulting high yield of spherical and relatively uniform micron‐size pMMA particles was formed utilizing various amounts of p(HDFDA‐co‐SiMA) random copolymer. The particle diameter was shown to be dependent on the weight percent of the stabilizer added to the system. The effects of varying the concentration of stabilizer (1–7 wt%), reaction time (4–12 h) and pressure (15–35 MPa) upon the polymerization yield, molar mass and morphology of pMMA were investigated. Copyright © 2005 Society of Chemical Industry     

Preparation and properties of amphoteric polyacrylamide by seeded dispersion polymerization in ammonium sulfate solution

Amphoteric polyacrylamide (AmPAM) was prepared successfully through seeded dispersion polymerization with acrylamide, methacrylatoethyl trimethyl ammonium chloride and acrylic acid as comonomers in ammonium sulfate solution. It was characterized by ¹H nuclear magnetic resonance (¹H NMR) and elemental analysis. The particle morphology and apparent viscosity of polymer dispersion were obtained by optical microscope and rotary viscometer, respectively. AmPAM dispersion was obtained with low apparent viscosity. The process was smooth without high viscosity stage. The data of ¹H NMR spectrum and elemental analysis indicated that all monomers had participated in the polymerization. The seeded reaction time and the mass ratio of two parts of monomers had significant effects on the dispersion polymerization. The best conditions were seeded reaction time 1.75h and the mass ratio 0.75. The apparent viscosity of AmPAM dispersion depended on the number of particles, particle size and low molecular weight polymer concentration in the continuous phase. AmPAM showed both anti‐polyelectrolyte effect and polyelectrolyte effect. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Dispersion copolymerization of acrylamide with acrylic acid in an aqueous solution of ammonium sulfate: Synthesis and characterization

Dispersion copolymerization of acrylamide with acrylic acid in an aqueous solution of ammonium sulfate using poly(2‐acrylamido‐2‐methylpropanesulfonic acid sodium) as the stabilizer and ammonium persulfate (APS) as the initiator was investigated. The influence of initiator concentration, stabilizer concentration, ammonium sulfate concentration, chain‐transfer agent concentration, and polymerization temperature on the copolymerization was discussed. The results showed that varying the ammonium sulfate concentration could affect the particle size and the intrinsic viscosity of the copolymer significantly. With increasing the stabilizer concentration, the particle size of the copolymer decreased first, and then increased, meanwhile the intrinsic viscosity of the copolymer decreased. The increase of initiator concentration, chain‐transfer agent concentration, and polymerization temperature resulted in the increase in the particle size. Polydisperse spherical particles were formed in the system, and the kinetics for the dispersion copolymerization were discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3685–3690, 2006     

Synthesis of methacrylate copolymers and their effects as pour point depressants for lubricant oil

In this study, polymethacrylate polymers were synthesized by free‐radical polymerization for use as pour point depressants in lubricant oil, and their low‐temperature properties were investigated. Four methacrylate monomers were synthesized by the esterification of methyl methacrylate (MMA) with four kinds of fatty alcohols. The purification step was performed to prepare the pure monomers. Two polymerization experiments were carried out with four kinds of methacrylate monomers obtained previously and MMA. Copolymers, which were made from one kind of monomer and MMA, and terpolymers, which were made from two kinds of monomers and MMA, were prepared. The molecular structures of the synthesized methacrylate monomers and polymethacrylate polymers were verified by ¹H‐NMR, and the molecular weight data were obtained by gel permeation chromatography. The pour points of the base oils containing 0.1 wt % polymethacrylate polymers were measured according to ASTM D 97‐93. The pour points of most base oils containing each polymer decreased compared to that of the pure base oil. Particularly, poly(dodecyl methacrylate‐co‐hexadecyl methacrylate‐co‐methyl methacrylate), made of dodecyl methacrylate, hexadecyl methacrylate, and MMA at a molar ratio of 3.5 : 3.5 : 3, showed the best low‐temperature properties. This terpolymer dropped the pour point of the base oil by as much as 23°C, and its yield was 93.5%. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Monosize polystyrene latices carrying functional groups on their surfaces

In this study, monosized polystyrene (PS) latices were prepared by dispersion polymerization of styrene in isopropanol-water media using poly(acrylic acid) (PAA) as a steric stabilizer and 2,2′-azobisizobutyronitrile (AIBN) as an initiator. The effects of initiator and stabilizer concentrations, alcohol/water and monomer/dispersion medium ratio on the polymerization kinetics, and the size and monodispersity of PS latices were experimented with in a stirred reactor system. Monosize PS beads in the size range of 1.0–3.0 μm were obtained. The PS latex obtained in the first step having a diameter of 2.3 μm were used as the seed latex, and styrene/acrylate monomers, acrylic acid (AA), 2-hydroxyethyl methacrylate (HEMA), and dimethylaminoethyl methacrylate (DMAEMA) were copolymerized onto the PS latex particles. The incorporation of functional groups to the surface and bulk structure of PS was confirmed by IR, FTIR, XPS, and zeta potential measurements. © 1994 John Wiley & Sons, Inc.     

Water‐soluble copolymers. V. Synthesis of low molecular weight amphoteric polyacrylamide by foamed copolymerization

Amphoteric polyacrylamide of acrylamide, acryloyloxyethyl trimethylammonium chloride, sodium acrylate, and acrylic acid was synthesized by foamed copolymerization. The effects of monomer concentration and composition, initiator concentration and composition, sodium bicarbonate and stabilizer content on the polymer intrinsic viscosity and monomer conversion were examined. The monomer conversion increased with increasing initiator concentration, sodium bicarbonate and stabilizer content. The polymer intrinsic viscosity decreased with increasing initiator concentration. The structure and low molecular weight of the amphoteric polymer were identified by fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC), respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

水性羟基丙烯酸树脂的制备与研究

以甲基丙烯酸甲酯(MMA)、苯乙烯(St)和丙烯酸丁酯(BA)等为主要单体,引入丙烯酸(AA)、丙烯酸羟基乙酯(HEA)与甲基丙烯酸异冰片酯(IBOMA)等作为功能单体,通过半连续溶液聚合工艺,最后加水分散制得水性羟基丙烯酸树脂。利用FT-IR、透光度、粘度分析研究了单体配比、引发剂(BPO)用量、温度、链转移剂(DDM)用量、功能单体用量等因素对树脂性能的影响。结果表明,当AA、HEA、IBOMA、BPO和DDM的质量分数分别为3%、12%、10%、3%和2%,聚合反应温度100℃时可获得粘度为5 Pa.s,固含量约45%的水性羟基丙烯酸树脂。     

碳纤维原丝用聚丙烯腈的聚合反应条件

采用水相沉淀聚合法,以过硫酸铵为引发剂,制备了丙烯腈-丙烯酸甲酯-甲叉丁二酸三元共聚物,研究了聚合温度、单体浓度、引发剂浓度对聚丙烯腈共聚物相对分子质量和单体转化率的影响。结果表明:当反应温度为58℃,反应时间为2.5 h,单体质量分数为25%,引发剂质量分数为1.5%时,聚合物的黏均分子质量达3.8×105,单体转化率为79%。