Synthesis and Thermal Behavior of Polyacrylonitrile/Vinylidene Chloride Copolymer

Fleming, Robson; Pardini, Luiz Carlos; Alves, Nilton Pereira; García, E. Riande; Brito, C. A. R.

doi:10.4322/polimeros.2014.065

Cited by 11 publications

(9 citation statements)

References 28 publications

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“…This value is very close to the previously reported T g of PAN (100 °C), [ 47 ], and ENR- 25 (−40 °C) [ 7 ]. However, a sharp exothermic peak between about 240 and 350 °C in PAN homopolymer is not exhibited in the thermogram, as reported by Preta et al [ 48 ] and Fleming et al [ 49 ], due to the measurement being carried out between −100 and 250 °C. This peak was due to dehydrogenation, oxidation, crosslinking, and cyclization reactions that were initiated by the free-radical mechanism.…”

Section: Resultsmentioning

confidence: 64%

Free-Radical Photopolymerization of Acrylonitrile Grafted onto Epoxidized Natural Rubber

et al. 2021

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The exploitation of epoxidized natural rubber (ENR) in electrochemical applications is approaching its limits because of its poor thermo-mechanical properties. These properties could be improved by chemical and/or physical modification, including grafting and/or crosslinking techniques. In this work, acrylonitrile (ACN) has been successfully grafted onto ENR- 25 by a radical photopolymerization technique. The effect of (ACN to ENR) mole ratios on chemical structure and interaction, thermo-mechanical behaviour and that related to the viscoelastic properties of the polymer was investigated. The existence of the –C≡N functional group at the end-product of ACN-g-ENR is confirmed by infrared (FT-IR) and nuclear magnetic resonance (NMR) analyses. An enhanced grafting efficiency (~57 %) was obtained after ACN was grafted onto the isoprene unit of ENR- 25 and showing a significant improvement in thermal stability and dielectric properties. The viscoelastic behaviour of the sample analysis showed an increase of storage modulus up to 150 × 103 MPa and the temperature of glass transition (Tg) was between −40 and 10 °C. The loss modulus, relaxation process, and tan delta were also described. Overall, the ACN-g-ENR shows a distinctive improvement in characteristics compared to ENR and can be widely used in many applications where natural rubber is used but improved thermal and mechanical properties are required. Likewise, it may also be used in electronic applications, for example, as a polymer electrolyte in batteries or supercapacitor.

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Section: Resultsmentioning

confidence: 64%

Free-Radical Photopolymerization of Acrylonitrile Grafted onto Epoxidized Natural Rubber

et al. 2021

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“…The DSC curve shows an exothermic peak at 80 °C, for instance, in the case of M1-16C on heating, while no peak was observed on cooling. The intensity of the peaks diminished in subsequent cycles as shown in Figure S8 (SI), which reveals an irreversible change in the polymer architecture due to crosslinking via −CN bonds, 42 which was further confirmed from the IR spectra. While comparing the FT-IR spectra before and after membrane casting, the intensity of the C−H bending peak of CC−H (810 cm −1 ) increases along with a new peak that appeared at 1628 cm −1 for the −CN stretching.…”

Section: R W T σ = • •mentioning

confidence: 56%

Pendent Persubstituted Imidazolium and a Polyimidazolium Cross-Linked Polymer as Robust Alkaline Anion Exchange Membranes for Solid-State Zn–Air Batteries

Singh

Kumar

Thomas

et al. 2021

ACS Appl. Energy Mater.

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Alkaline anion exchange membranes (AEMs) were developed from a series of persubstituted imidazolium cations with varying alkyl chains (Im-nC, nC = (CH2) n−1CH3; n = 4, 12, and 16) tethered on poly(vinylbenzyl chloride-co-acrylonitrile) (PVC-co-AN) to prepare a comb-shaped polymer membrane (M1-nC) and a cross-linked polymer membrane from polyimidazolium cations and PVC-co-AN (M3). The PVC-co-AN polymer backbone shows high stability after curing, and the water uptake and swelling ratio are controlled by varying the alkyl chain length in M1-nC even with temperature variation. Results show that M1-16C retains the highest ion exchange capacity (IEC) of 95% among the M1-nC series of membranes after exposure to 1 M KOH solution at 80 °C for 30 days. However, the longer alkyl chains hindered the interconnected ion channels limiting the hydrophobic/hydrophilic phase separation and the hydroxide ion conductivity. Meanwhile, M3 exhibits a distinct microphase-separated morphology and a high ionic conductivity of 54.5 mS/cm for a 2.02 IEC with high stability to retain an IEC of 97% after storage in 1 M KOH solution at 80 °C for 30 days. In addition, all the AEMs exhibit high oxidation stability and retain >96% weight after immersion into 4 ppm Fenton’s reagent at 80 °C. Moreover, the flexible solid-state zinc–air batteries comprising an M3 membrane displayed a peak power density of 165 mW cm–2 and superior cycling stability (30 h at 10 mA cm–2) demonstrating very promising applications in solid-state flexible rechargeable Zn–air batteries.

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“…The rate of copolymerization (RP) and the productivity of the reactor (PROD) regression equations follow similar behavior with tres and CAN0 as independent variables, with a good adjustment of the data. The equation for RP is similar to literature, 7,10 taking into account that acrylonitrile is a major comonomer.…”

Section: Mass Balancesmentioning

confidence: 75%

“…In industrial practice, the polymerization of acrylonitrile and its copolymerization are conducted in constantly agitated reactor tanks, operating at steady state in both solvent medium and aqueous media. 6,7 The main factors that influence the polymerization process are the type of redox system used, the concentration of monomers in the reactor, their relative proportion, the residence time in the reactor, and the reaction temperature. One of the important factors in the development and implementation of production strategies and successful control for copolymerization reactors is the availability of kinetic models that adequately describe the polymerization rate and the properties of the resulting polymer as functions of process variables.…”

Section: Introductionmentioning

confidence: 99%

Industrial process of copolymerization and terpolymerization of acrylonitrile: experimental approach and statistic modeling

Marlet

Bittencourt

2015

Advanced Manufacturing: Polymer & Composites Science

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The interest for models on a polymerization plant of acrylonitrile is (a) to predict the maximum capacity of an industrial reactor, (b) to increase the robustness of the process by defining stable operational conditions, and (c) to help the development of new copolymers. Using design of experiments (DOE), the copolymerization and terpolymerization of acrylonitrile with vinyl acetate and methyl-2 propene-1 sodium sulfonate were studied in aqueous suspension initiated by the redox system KClO 3 /NaHSO 3 /Fe 2þ . The molar fraction of the copolymers and terpolymers produced ranged from 93.0 to 98.2% for acrylonitrile, from 1.7 to 7.0% for vinyl acetate, and from 0.0 to 0.5% for sodium sulfonate. The mass molecular weight ranged from 76 000 to 419 000 g/gmol. Experiments were done in a pilot plant, consisting of 227 L of continuously stirred tank reactor, stripping and recycle systems, drum filter, and band dryer. The experiments were conducted according to a fractioned factorial 2 823 matrix with five central points. A statistic kinetic model was built, which explains well the copolymerization and terpolymerization of acrylonitrile. This model was applied with success on an industrial polymerization reactor, showing the potential of production increase, confirming the robustness of the process, and supporting the development of new copolymers of acrylonitrile. The focus of this paper is the development of a kinetic statistical polymerization model, the criteria to interrupt the regression analysis, and its application in the understanding of the polymerization phenomena.

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Synthesis and Thermal Behavior of Polyacrylonitrile/Vinylidene Chloride Copolymer

Cited by 11 publications

References 28 publications

Free-Radical Photopolymerization of Acrylonitrile Grafted onto Epoxidized Natural Rubber

Free-Radical Photopolymerization of Acrylonitrile Grafted onto Epoxidized Natural Rubber

Pendent Persubstituted Imidazolium and a Polyimidazolium Cross-Linked Polymer as Robust Alkaline Anion Exchange Membranes for Solid-State Zn–Air Batteries

Industrial process of copolymerization and terpolymerization of acrylonitrile: experimental approach and statistic modeling

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