Kinetics of cyclization reaction in poly(acrylonitrile/methyl acrylate/dimethyl itaconate) copolymer determined by a thermal analysis

Rwei, Syang‐Peng; Way, Tun-Fun; Hsu, Yuan-Shuin

doi:10.1016/j.polymdegradstab.2013.07.003

Cited by 25 publications

(28 citation statements)

References 26 publications

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“…This mechanism may be reasonable to explain the different behaviors of structural evolution of P(AN‐DMI) copolymer, compared to PAN homopolymer, because the cyclic anhydride has a stronger nucleophilic reactivity than free radical. But they did not directly prove the formation of cyclic succinic anhydride during the thermal treatment of PAN polymers which contain the DMI comonomer . Fortunately, we found the direct evidence about the formation of cyclic succinic anhydride during the thermal treatment of P(AN‐DMI) copolymer.…”

Section: Resultsmentioning

confidence: 56%

“…But they did not directly prove the formation of cyclic succinic anhydride during the thermal treatment of PAN polymers which contain the DMI comonomer. [7] Fortunately, we found the direct evidence about the formation of cyclic succinic anhydride during the thermal treatment of P(AN-DMI) copolymer. Figure 8 gives the corresponding results of P(AN-DMI) copolymer and PAN homopolymer thermal treated in air at 240°C for 60 min.…”

Section: Structural Evolution Of P(an-dmi) and Pan During Tosmentioning

confidence: 66%

“…It is very attractive to notice that the extent of cyclization reactions of P(AN‐DMI) is significantly higher than that of PAN for all times, indicating that DMI comonomer has the ability to accelerate the cyclization reactions by some kinds of mechanisms. Way et al proposed a possible mechanism that a cyclic succinic anhydride formed by the thermal degradation of DMI comonomer, which reacted with nitrile groups introducing the cyclization reactions (Scheme ). This mechanism may be reasonable to explain the different behaviors of structural evolution of P(AN‐DMI) copolymer, compared to PAN homopolymer, because the cyclic anhydride has a stronger nucleophilic reactivity than free radical.…”

Section: Resultsmentioning

confidence: 99%

“…[5] Recently, Way et al reported that a special ester comonomer, dimethyl itaconate (DMI), in P(AN-MA-DMI) terpolymers can enable the melt processibility at 175-210°C, while it has a kinetic advantage in accelerating the cyclization reactions and reducing the stabilization temperature during the TOS studied by differential scanning calorimeter (DSC) method. [6,7] However, they paid no attention to the structural evolution of the poly(acrylonitrileco-dimethyl itaconate) [P(AN-DMI)] copolymer during the TOS. As is well known, the performance of the resulted CFs strongly depends on the structural evolution of precursors during the TOS.…”

Section: Introductionmentioning

confidence: 99%

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Structural evolution of poly(acrylonitrile‐co‐dimethyl itaconate) copolymer during thermal oxidative stabilization

Deng

et al. 2015

Polymers for Advanced Techs

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The structural evolution of poly(acrylonitrile-co-dimethyl itaconate) [P(AN-DMI)] copolymer was investigated by Fourier transform infrared spectroscopy (FTIR) in detail and compared with the polyacrylonitrile (PAN) homopolymer. The extent of cyclization reactions was calculated from the FTIR data. It was found that DMI comonomer had the ability to promote the cyclization reactions significantly at the temperature of 240°C, compared to the PAN homopolymer. The results of quantitative FTIR analysis in the range of 1000-1800 cm À1 showed that the DMI comonomer not only promoted the cyclization reactions, but also facilitated the oxygen uptake reactions, especially the conjugated carbonyl group in an acridone ring in the ladder polymer chains, which proved that DMI comonomer had the potential ability to make successful thermal oxidative stabilization (TOS) process. The positive effects of DMI comonomer on TOS reactions and carbon yield were further confirmed by the dynamic thermogravimetry (TG) analysis.

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Section: Resultsmentioning

confidence: 56%

Section: Structural Evolution Of P(an-dmi) and Pan During Tosmentioning

confidence: 66%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Structural evolution of poly(acrylonitrile‐co‐dimethyl itaconate) copolymer during thermal oxidative stabilization

Deng

et al. 2015

Polymers for Advanced Techs

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“…41 These two methods can be used to quantify E a without any prior knowledge of reaction mechanism but just requiring a series of DSC curves heated at different rates. 42 The peak temperature (T m ), used by Kissinger and Ozawa methods to evaluate E a , are summarized in Table 7. The T m of DSC shows a regular increase with the increase of heating rate (4).…”

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confidence: 99%

Poly(acrylonitrile-co-2-methylenesuccinamic acid) as a potential carbon fiber precursor: preparation and stabilization

et al. 2017

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A novel bifunctional comonomer 2-methylenesuccinamic acid (MLA) was synthesized to prepare poly(acrylonitrile-co-2-methylenesuccinamic acid) [P(AN-co-MLA)] copolymers, which can improve the stabilization of polyacrylonitrile significantly as a carbon fiber precursor. The structure and stabilization of P(AN-co-MLA) copolymers with different monomer feed ratios of AN/MLA were characterized by elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Reactivity ratio studies shows that MLA possesses higher reactivity than AN, resulting in higher MLA content in P(AN-co-MLA) copolymers than in the feed. The molecular weight and conversion of copolymer decrease gradually with the increase of MLA content in the feed. Comparing with PAN homopolymer, P(AN-co-MLA) copolymer has two or even three exothermic peaks, and the initial temperature of P(AN-co-MLA) copolymer is ca. 70 C lower than that of PAN, which broadens the exothermic peak. The DH/DT reduces from 34.01 J g À1 C À1 to less than 17.67 J g À1 C À1, confirming that the incorporation of MLA can avoid centralized heat release effectively.In addition, the extent of stabilization increases as the MLA content in P(AN-co-MLA) copolymer increases under the same heat treatment conditions. The activation energy (E a ) calculation shows cyclization E a of P(AN-co-MLA) reduces from ca. 168 kJ mol À1 to ca. 110 kJ mol À1, it is concluded that synthesized comonomer MLA can significantly improve stabilization of PAN, which is conducive to the preparation of high performance carbon fiber.

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Reversible addition–fragmentation chain transferbased copolymers of acrylonitrile and alkyl acrylates as possible precursors for carbon fibers: synthesis and thermal behavior during stabilization

Томс

Balashov

Gervald

et al. 2021

Polymer International

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Copolymers of acrylonitrile and alkyl acrylates with various alkyl substituents (methyl, ethyl, butyl, 2‐ethylhexyl and lauryl) were synthesized via reversible addition–fragmentation chain transfer polymerization in dimethylsulfoxide. It is demonstrated that reactivity of alkyl acrylate in copolymerization decreases with increase of the length of the alkyl substituent. The molar fractions of homodiads and homotriads of acrylonitrile and the number‐average sequence length of acrylonitrile units decreases with a decrease in the acrylate content in the copolymer or with an increase in the length of the alkyl substituent in the acrylate. The copolymer composition was held constant throughout copolymerization in all the studied systems resulting in the formation of copolymers with high compositional homogeneity. Additionally the reversible addition–fragmentation chain transfer mechanism provides low dispersity of the copolymers. Both factors enable the effect of the alkyl substituent in alkyl acrylate on the thermal behavior of acrylonitrile copolymers to be carefully revealed. Being inert in the cyclization reaction, alkyl acrylates have no effect on the activation energy of the reaction. However, increase of the length of the alkyl substituent is followed by a slower evolution of the ladder structure. In contrast, in conditions of oxidative stabilization, the stabilization index increases in the order of increase of the number‐average sequence length of the acrylonitrile units in the copolymers. Thus, the use of alkyl acrylates with longer alkyl substituents provides an increase of chain flexibility and the formation of an enhanced ladder structure during oxidative stabilization which is profitable for carbon fiber production. © 2021 Society of Industrial Chemistry.

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Kinetics of cyclization reaction in poly(acrylonitrile/methyl acrylate/dimethyl itaconate) copolymer determined by a thermal analysis

Cited by 25 publications

References 26 publications

Structural evolution of poly(acrylonitrile‐co‐dimethyl itaconate) copolymer during thermal oxidative stabilization

Structural evolution of poly(acrylonitrile‐co‐dimethyl itaconate) copolymer during thermal oxidative stabilization

Poly(acrylonitrile-co-2-methylenesuccinamic acid) as a potential carbon fiber precursor: preparation and stabilization

Reversible addition–fragmentation chain transferbased copolymers of acrylonitrile and alkyl acrylates as possible precursors for carbon fibers: synthesis and thermal behavior during stabilization

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