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The thermal decomposition of the thermodynamic, kinetic and mechanisms of copolymer P(DAC-AM) samples with serial cationicity and intrinsic viscosity ([η]), and the control samples of homopolymer PAM and PDAC, were studied and analyzed using TG, DSC, FTIR. The results of the thermal decomposition thermodynamics confirmed that the thermal decomposition processes of the serial P(DAC-AM) samples and the two control samples could be divided into two stages. It was found that the processes of the copolymer P(DAC-AM) samples were not a simple superposition of those of homopolymers, whose monomers had composed the unit structures of the copolymer, but there were interactions between the two suspension groups. The results of thermal decomposition kinetics showed that the apparent activation energy (E) of the thermal decomposition process of all polymer samples had different varying trends in the terms of weight-loss rate (α). The reaction order (n) of the thermal decomposition of P(DAC-AM) in Stage I and II was close to 1, but in the former and the latter it tended to be 2 and 0.5, respectively. Finally, the thermal decomposition mechanism of copolymer P(DAC-AM) samples was discussed. The above research could not only fill in the knowledge vacancy of the thermal decomposition of the thermodynamic, kinetic and mechanisms of P(DAC-AM), but could also lay a foundation for the study of thermal decomposition mechanisms of the other types of polymers, including cationic polymers. [ABSTRACT FROM AUTHOR]

Poly(3-methacrylamido propyl trimethyl ammonium chloride) (PMAPTAC) is a typical cationic water-soluble polyelectrolyte, which has been widely used in petroleum, papermaking, daily cosmetics and other fields in the form of an aqueous solution. However, the acid–base and thermal stability of PMAPTAC in aqueous solution have not been reported yet, which hinders its further application in high-temperature and acid–base environments. To address these deficiencies, the effects of temperature and pH of PMAPTAC with different intrinsic viscosities on its hydrolysis stability were investigated qualitatively and quantitatively, and the hydrolysis mechanism was studied. Firstly, the qualitative analysis showed that the apparent viscosity of the PMAPTAC solution decreased with hydrolysis time at different temperatures and pH. The higher the temperature and the lower the pH, the greater the viscosity loss of PMAPTAC. The quantitative analysis showed that the hydrolysis rate of the PMAPTAC sample solution increased with the increase in temperature and pH. In addition, the intrinsic viscosity of PMAPTAC samples had little effect on the hydrolytic stability of PMAPTAC. Secondly, by analyzing the viscosity curves at different pH and temperatures by Arrhenius analysis, the Arrhenius equations were found to be 1/τ = 200.34e^((−25.04)/RT), 1/τ = 9127.07e^((−38.90)/RT) and 1/τ = 4683.03e^((−39.89)/RT) for pH 3, pH 7 and pH 11, respectively. Thirdly, the hydrolysis rate of PDMC was the fastest under alkaline conditions. In addition, compared with PDMC, PMAPTAC had better hydrolysis stability under the same conditions. Finally, the mechanism of the hydrolyzed polymer was studied by FTIR and 13CNMR, which showed that the carbonyl group of PMAPTAC was hydrolyzed into a carboxyl group, and the small molecule (3-aminopropyl) trimethylammonium chloride was generated, while the ester group of PDMC was hydrolyzed into a carboxyl group, and choline chloride was released. The above results can provide a theoretical basis for the application of PMAPTAC in some high-temperature and acid–base environments. [ABSTRACT FROM AUTHOR]

In this paper the thermal stability properties of poly(3-methacryloylamino propyl trimethyl ammonium chloride) (PMAPTAC) with a series of molecular weights in various salt solutions were investigated by monitoring the apparent viscosity and viscosity retention rate with aging time, for the first time to our knowledge. Secondly, the thermal stability properties of poly(methacryloyloxy ethyl trimethyl ammonium chloride) (PDMC) solution was studied and compared with that of the PMAPTAC solution under the same conditions. The results showed that the viscosity retention rate of PMAPTAC/salt solutions with salinities from 40 g/L to 200 g/L at 85 °C were about 60%, indicating that PMAPTAC had good temperature and salt resistance. Besides, the temperature and salt resistance of PMAPTAC with 0.62 dL/g was better than that of PMAPTAC with 7.55 dL/g under the conditions of this study. In addition, the viscosity retention rate of PDMC/salt solution with the same intrinsic viscosity as PMAPTAC/salt solution was 45%, indicating that compared with PDMC, the PMAPTAC with viscosity retention rate of 60% had better temperature and salt resistance. We suggest the results obtained in this study will not only fill the current gaps in the research of the temperature and salt tolerance properties of PMAPTAC, but also provide support for the potential application of PMAPTAC products in high-temperature and high-salt environments. [ABSTRACT FROM AUTHOR]

The lipophilic modification of dimethyldiallylammonium chloride monomer (DMDAAC) with resulting excellent lipophilic performance can provide an effective way to improve the application performance of the resulting monomers and copolymers. In this paper, polymethylamyldiallylammonium chloride (PMADAAC) homopolymer was prepared by using methylamyldiallylammonium chloride (MADAAC) as the monomeric unit, 2,2'-Azobis(2-methylpropionamide) dihydrochloride (V50) as the initiator and ethylenediaminetetraacetic acid tetrasodium (Na4EDTA) as a metal ion complexing agent via an aqueous solution polymerization method. Using the intrinsic viscosity of the product as the inspection index, the polymerization reaction conditions were optimized by the response surface optimization method, and the optimum conditions obtained were: w(MADAAC)=70.2%, m(V50):m(MADAAC)=2.05%, m(Na4EDTA):m(MADAAC) =0.0141%, T1=55.0 °C, T2=60.0 °C and T3=80.1 °C, with the reaction lasting 9 h (see below). The average value of the intrinsic viscosity ([η]) of the obtained product was 0.84 dL/g, and the monomer conversion degree (Conv.) was 72.77%. The molecular weight characterizations of PMADAAC showed that the highest Mw of PMADAAC was 2.380 × 105 and its polydispersity index d(Mw/Mn) was 1.952 for optimum properties. The results indicated that the introduction of the amyl group could increase the lipophilicity of the diallyl quaternary ammonium salts based on its good water solubility. For the demulsification performance of simulated crude oil O/W emulsions, the demulsification degrees were 88.9% for PMADAAC, 83.6% for polymethylpropyldiallylammonium chloride (PMPDAAC) and 45.5% for polydimethyldiallylammonium chloride (PDMDAAC), all at the same intrinsic viscosity. [ABSTRACT FROM AUTHOR]

Quaternary ammonium salt polymers, a kind of polyelectrolyte with a quaternary ammonium group, are widely used in traditional and emerging industries due to their good water-solubility, adjustable cationicity and molecular weight, high efficiency and nontoxicity. In this paper, firstly, the properties and several synthesis methods of typical quaternary ammonium salt monomers were introduced. Secondly, the research progress on the synthesis of polymers was summarized from the perspective of obtaining products with high molecular weight, narrow molecular weight distribution and high monomer conversion, and special functional polymers. Thirdly, the relationships between the structures and properties of the polymer were analyzed from the perspectives of molecular weight, charge density, structural stability, and microstructural regulation of the polymer chain unit. Fourthly, typical examples of quaternary ammonium salt polymers in the application fields of water treatment, daily chemicals, petroleum exploitation, papermaking, and textile printing and dyeing were listed. Finally, constructive suggestions were put forward on developing quaternary ammonium salt polymers with high molecular weights, strengthening the research on the relationships between the structures and their properties and pinpointing relevant application fields. [ABSTRACT FROM AUTHOR]