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。     

分散聚合法制备阳离子聚丙烯酰胺水包水乳液

本文以聚乙二醇20000(PEG20000)为分散稳定剂、过硫酸铵/亚硫酸氢钠(APS/SB)为引发体系,将丙烯酰胺(AM)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)进行分散聚合得到了水包水型阳离子聚丙烯酰胺乳液。利用正交试验法考察了分散剂用量、单体浓度、引发剂浓度、温度等参数对聚合物絮凝性能的影响;用乌氏粘度计、红外光谱仪等对产品进行了表征。实验结果表明:40℃,引发剂用量0.5m L,单体用量5g,聚合温度40℃,PEG用量5g时,产品稳定性和絮凝性都较好。     

甲基丙烯酰氧乙基三甲基氯化铵与丙烯酰胺的合成研究

丙烯酰胺(AM)与甲基丙烯酰氧乙基三甲基氯化铵(DMC)进行水溶液聚合,考察了引发剂浓度、温度、单体配比、pH值、引发剂等因素对共聚物的阳离子度、特性黏度以及相对分子质量的影响。结果表明,制备高相对分子质量的阳离子型聚丙烯酰胺的最佳工艺条件为:pH为8,温度为50℃,引发剂的用量为0.8 mmol/L,DMC∶AM(摩尔比)=1∶3。     

高分子量阳离子型污泥脱水剂的合成

采用复合引发体系(氧化-还原体系和V-50复合),根据水溶液自由基聚合反应合成了丙烯酰胺、丙烯酰氧乙基三甲基氯化铵、甲基丙烯酰氧乙基三甲基氯化铵的共聚物。用正交实验研究了单体浓度、引发剂用量等对聚合反应的影响。结果表明,最佳合成工艺条件为:单体浓度25%、氧化还原引发剂浓度0.015%、V-50浓度0.075%、单体配比(质量比)为2∶1∶1,在此条件下,制得了特性粘度[η]达16 dL/g的聚合物。     

新型温控变黏酸的合成与性能研究

以丙烯酰胺、2-丙烯酰胺-2-甲基丙磺酸和甲基丙烯酰氧乙基三甲基氯化铵为共聚单体,引入各种功能性单体,以偶氮二异丁脒盐酸盐引发合成一种新型温控变黏酸稠化剂;研究了不同交联剂用量对温控变黏酸交联效果的影响,以及丙烯酰胺与2-丙烯酰胺-2-甲基丙磺酸重量比、甲基丙烯酰氧乙基三甲基氯化铵用量、丙烯腈用量对变黏酸温控变黏过程的影响,同时评价了温控变黏酸的交联与破胶降解能力。     

阳离子聚丙烯酰胺水包水乳液合成

阳离子聚丙烯酰胺作为一种高分子物质,具有高效、环保和价廉等很多的优势,但不同的制备方法对水乳液絮凝剂的性能具有不同的影响。对此,以丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体,以分散聚合技术作为主要合成方法,以硫酸铵作为反应介质,合成一种CPAM絮凝剂,并充分讨论了不同单体总量与配比、反应温度、反应时间、硫酸铵浓度、引发剂种类等多种因素对阳离子聚丙烯酰胺的影响。最后通过红外光谱等的分析,验证了合成的阳离子聚丙烯酰胺具有较好的稳定性、流动性等特点。     

KH550改性阴离子型聚丙烯酰胺的制备

以丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)、乙二酸四乙酸二钠、四甲基乙二胺(TMEDA)作为主要反应单体,以偶氮二异丁氰(AIBA)作为引发剂,首先合成聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC),再用阴离子单体丙烯酸(AA)和3-氨丙基三乙氧基硅烷(KH550)进行改性,利用水分散聚合技术合成KH550改性的阴离子型聚丙烯酰胺水分散体系。通过离心机对实验制备的阴离子型聚丙烯酰胺水分散体系的稳定性进行测试,确定了使水分散体系达到稳定时各条件的范围:w(AM)%=3%~13%;w(PDMC)=2%~5%;w(KH550)%=10%~30%;w(AA)%=10%~25%。     

页岩气压裂用抗盐速溶滑溜水降阻剂的制备及性能评价

以丙烯酰胺(AM)和二甲基二烯丙基氯化铵(DADMAC)为聚合单体,自制聚甲基丙烯酰氧乙基三甲基氯化铵(P-DMC)为分散剂,水溶性偶氮二异丁脒盐酸盐(V-50)为引发剂,以乙醇-水体系为分散介质,采用分散聚合法合成了阳离子型聚丙烯酰胺乳液降阻剂。通过单因素实验确定了共聚物合成的较佳条件:单体配比n(AM)∶n(DADMAC)=6∶1,单体加量占聚合体系总质量的40%(w),分散剂加量对单体总质量占比为8%(w),分散介质m(乙醇)∶m(水)=50%,引发剂加量对单体总质量占比为0.2%(w),聚合温度60℃,反应时长8 h。结果表明,合成产物稳定性良好,分子量达1.26×10~6,在矿化度为30 000 mg/L的模拟水中黏度保持率达78.6%,质量分数0.2%的聚合物溶液降阻率最高可达66.4%,可在10 min内完全溶解,在页岩气井压裂开采过程中具有广阔的应用前景。     

页岩气压裂用抗盐速溶滑溜水降阻剂的制备及性能评价

以丙烯酰胺(AM)和二甲基二烯丙基氯化铵(DADMAC)为聚合单体,自制聚甲基丙烯酰氧乙基三甲基氯化铵(P-DMC)为分散剂,水溶性偶氮二异丁脒盐酸盐(V-50)为引发剂,以乙醇-水体系为分散介质,采用分散聚合法合成了阳离子型聚丙烯酰胺乳液降阻剂。通过单因素实验确定了共聚物合成的较佳条件:单体配比n(AM)∶n(DADMAC)=6∶1,单体加量占聚合体系总质量的40%(w),分散剂加量对单体总质量占比为8%(w),分散介质m(乙醇)∶m(水)=50%,引发剂加量对单体总质量占比为0.2%(w),聚合温度60℃,反应时长8 h。结果表明,合成产物稳定性良好,分子量达1.26×10⁶,在矿化度为30 000 mg/L的模拟水中黏度保持率达78.6%,质量分数0.2%的聚合物溶液降阻率最高可达66.4%,可在10 min内完全溶解,在页岩气井压裂开采过程中具有广阔的应用前景。     

DMMC-AM水溶液共聚合及其应用的研究

研究水溶液聚合方法合成聚 2 -甲基丙烯酰氧乙基三甲基氯化铵 (DMMC) -丙烯酰胺(AM)阳离子型共聚物的方法 ;分析讨论了单体浓度、引发剂浓度和聚合体系pH值对共聚物特性粘数的影响 ;并在丙纶地毯短纤维上进行了抗静电性能实验。     

Atom transfer radical suspension polymerization of methyl methacrylate catalyzed by CuCl/bpy

Atom transfer radical suspension polymerization (suspension ATRP) of methyl methacrylate (MMA) was carried out using 1-chloro-1-phenylethane (1-PECl) as initiator, copper chloride/bipyridine (CuCl/bpy) as catalyst. The polymerization was accomplished with a mechanical agitator under the protection of nitrogen atmosphere. Apart from the dispersing agent (1% PVA), NaCl was also used in the water phase to decrease the diffusion of CuCl/bpy to water and the influence of the concentration of NaCl was investigated. Subsequently, the kinetic behavior of the suspension ATRP of MMA at different temperatures was studied. At 90 and 95 °C, the polymerization showed first order with respect to monomer concentration until high conversion. The molecular weight (M_n) of the polymer increased with monomer conversion. However, at lower temperatures, different levels of autoacceleration was observed. The polymerization deviated from first order with respect to monomer concentration when the conversion was up to some degree. The lower the temperature was, the more the deviation displayed. On comparison with bulk ATRP of MMA, the rate of suspension ATRP was much faster.     

反相微乳液聚合引发剂对聚丙烯酰胺分子质量影响的研究

分别以三种引发剂体系为引发剂,从引发机理出发,通过正交实验研究了丙烯酰胺反相微乳液聚合中引发剂种类、引发剂浓度、反应温度、单体浓度等对聚丙烯酰胺(PAM)相对分子质量的影响。结果表明,引发剂种类对水溶性PAM相对分子质量有显著的影响;过硫酸铵-亚硫酸氢钠和偶氮二异丁腈复合引发体系是合成高相对分子质量PAM的有效引发体系。该引发体系在反应温度为40℃,氧化还原引发剂与偶氮的质量比为1∶4,单体浓度为20%,引发剂浓度为0.3%,pH为9的最佳条件下合成的PAM相对分子量为1.44×107。     

Preparation of amphoteric polyacrylamide flocculant and its application in the treatment of tannery wastewater

Through two‐phase aqueous polymerization, amphoteric polyacrylamide (AmPAM) emulsion, as an environmental friendly flocculant for the tannery wastewater, was firstly synthesized using ammonium sulfate aqueous solution as the dispersion, using acrylamide, cationic monomer ethylene methyl propenoyl‐trimethylammonium chloride (DMC), and anionic monomer acrylic acid (AA). The structure and properties of the synthesized AmPAM were characterized by means of FT‐IR measurement, and the effects of various factors were studied, such as dispersing agent, dispersion medium concentration, initiator concentration, and AA/DMC feeding ratio on the intrinsic viscosity of the emulsion. The influences of pH, the AA/DMC feeding ratio, the intrinsic viscosity, and the dosage of polymer on the flocculating performance were also studied. When the weight percent of ammonium sulfate was 10.0% of emulsion total weight and dispersing agent polyvinylpyrrolidone was 1.2% and the weight percent of initiator was 4.0% of monomer total weight and m (acrylamide): m (DMC): m (AA) was 9: 5: 3, AmPAM achieved overall performance, good solubility, high stability, and application in a wide range of pH value between 4 and 10. The flocculating rate was more than 90.0%. AmPAM flocculant with both anionic group and cationic group provided a clear antipolyelectrolyte effect and a wide pH value range of the application, especially for tannery wastewater. It had not only charge neutralization and adsorption bridging role but also winding and enclosing effect among the molecules so as to flocculate and subside coarse particles of the sludge treated and dehydrate perfectly. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Kinetics of emulsifier–free emulsion polymerization of methyl methacrylate

The influences of polymerization temperature, initiator and monomer concentrations, ionic strength of the aqueous phase, as well as ethylene glycol dimethacrylate (EGDM) co-monomer, on the kinetics of the emulsifier-free emulsion polymerization of methyl methacrylate (MMA) and on the properties of the resulting poly(methyl methacrylate) (PMMA) lattices were studied. The polymerizations were carried out using potassium persulfate (KPS) as the initiator. Monodisperse PMMA lattices with particle diameters varying between 0.14–0.37 μm and polymer molecular weights of the order 0.4 × 10⁶ to 1.2 × 10⁶ g/mol were prepared. The initial rate of polymerization increases with increasing temperature, KPS-MMA mole ratio, EGDM content, or with decreasing ionic strength of the aqueous phase. It was shown that the bead size can be limited by reducing the monomer concentration or by using the cross-linking agent EGDM. The ionic strength of the aqueous phase has a dominant effect on final particle diameter and polymer molecular weight. The uniformity of the latex particles increases as the temperature increases or as the initiator concentration decreases. The experimental results can be reasonably interpreted by the homogeneous nucleation mechanism of the emulsifier-free emulsion polymerization of MMA. © 1996 John Wiley & Sons, Inc.     

Aqueous dispersion polymerization of amphoteric polyacrylamide

The terpolymer of acrylamide (AM), dimethylaminoethyl methacrylate methyl chloride (DMC), and acrylic acid (AA) was synthesized with their molar ratio of 70 : 15 : 15 through dispersion polymerization in aqueous solution of ammonium sulfate (AS), using poly(dimethylaminoethyl methacrylate methyl chloride) (PDMC) as stabilizer and 2,2′‐azobis(2‐amidinopropane) dihydrochloride (V‐50) as initiator. The particle size of the terpolymer ranged from 5 to 8 μm and the intrinsic viscosity was from 5.5 to 11.6 dL g^?1. The terpolymer had anti‐ polyelectrolyte effect under low AS concentration, but polyelectrolyte effect with the concentration beyond 10%. Polymerization dispersion with low apparent viscosity, uniform particles, good stability, and high molecular weight terpolymer was obtained in single stage. The effects of varying concentrations of salt, stabilizer, and monomers on particle morphology and intrinsic viscosity were investigated. With increasing concentration of AS and PDMC, the intrinsic viscosity of terpolymer increased, then decreased afterward. However, it increased gradually with increase in monomer concentration. The particle size was enlarged with increasing of AS and monomer concentration and decreasing of PDMC concentration. The optimum condition was the concentrations of salt, stabilizer, and monomers 28%, 3.0%, and 8% to 15%, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

微波辐射法合成阴离子型聚丙烯酰胺

以丙烯酰胺（AM）和丙烯酸钠（AA-Na）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,用微波辐射进行水溶液聚合制备可溶解的阴离子型聚丙烯酰胺。探讨丙烯酸中和度、单体浓度、引发剂用量、交联剂用量及温度等对相对分子质量的影响。结果表明,单体浓度为19%,中和度为80%,引发剂用量为0.05%,交联剂用量为0.002%,反应温度35℃条件下合成的聚丙烯酰胺（PAM）的相对分子质量最高。     

悬浮聚合法制取不同分子量级别的聚甲基丙烯酸甲酯

采用粉状MgCO3 作为分散剂 ,悬浮聚合制取了分子量从 2 4× 10 4 ～ 2 5 4× 10 4 的聚甲基丙烯酸甲酯。考察了温度、引发剂种类和浓度、分子量调节剂、转化率对聚合物分子量的影响规律 ,用粘度法测量了聚合物聚甲基丙烯酸甲酯 (PMMA)的分子量。结果表明 :温度的升高、引发剂浓度的增大、分子量调节剂的加入都会导致分子量的减小 ,随着转化率的提高 ,聚合物的分子量增大。在同等条件下 ,引发剂过氧化苯甲酰 (BPO)聚合所得的分子量较偶氮二异丁腈 (AIBN)高。通过实验 ,得到了满足作者需求的分子量 (96× 10 4 ～ 10 0× 10 4 )的聚合物的聚合条件为 :分散剂MgCO3 用量 1% ,单体∶水相 =1∶2 5 (质量比 ) ,引发剂BPO浓度 0 5 % ,反应温度 70℃ ,反应时间 3h。     

单分散微米级PMMA微球的制备

以聚乙烯吡咯烷酮(PVP)为分散剂,乙醇和水为反应介质,偶氮二异丁腈为引发剂,甲基丙烯酸甲酯(MMA)为单体,采用分散聚合工艺,制备了单分散微米级PMMA微球。研究了乙醇/水介质的配比、反应温度、分散剂用量、单体用量、引发剂用量对PMMA微球粒径和粒径分布的影响。结果表明,PMMA微球粒径随乙醇用量的增加先增大后减小;随反应温度的升高先增大后减小,粒径分布先变窄再变宽;随单体用量的增加先增大后减小,随引发剂用量的增加而增大;随PVP用量的增加而减小,粒径分布先变窄再变宽。     

低分子量聚N-乙烯基甲酰胺-co-乙烯胺的合成

以N-乙烯基甲酰胺为单体,N,N-二甲基甲酰胺和乙酸乙酯为混合溶剂,偶氮二异丁腈为引发剂,十二硫醇为链转移剂,通过沉淀聚合法制备了低分子量的聚N-乙烯基甲酰胺。详细研究了单体质量分数、混合溶剂配比、引发剂用量、链转移剂用量、反应温度及反应时间对聚合反应的影响。在最佳聚合条件下,聚合物收率可达93.1%、聚合物的数均分子量(Mn)为2 975.2,PDI=2.64,且聚合残液可循环利用。然后将所得聚合物在酸性条件下水解,制备了不同胺化度的聚N-乙烯基甲酰胺-co-乙烯胺,产品的数均分子量为1 000~1 400,PDI为1.34~1.40。     

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