Novel Synthesis of Poly(thioarylene)s <i>via</i> Reaction between Arenethiols and Bromo Compounds with a Free Radical Initiator

Ding, Yong; Hay, Allan S.

doi:10.1021/ma970395f

Cited by 13 publications

(9 citation statements)

References 31 publications

(72 reference statements)

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“…(2), an ipso substitution of aryl iodide by arylthiyl radical produces an unsymmetrical diaryl sulfide and an iodine radical, which is converted to I 2 . 13,16 Similar ipso substitution of a diaryl thioether moiety by arylthiyl radical was proposed in the radical ring-opening polymerizations of macrocyclic aryl ether thioether ketone oligomers and related cyclic oligomers where arylthiyl radicals are expelled: [17][18][19][20] ArOSSOAr O ¡ As described earlier, both nitrobenzene and p-chloronitrobenzene gave diphenyl sulfide in the reaction with diphenyl disulfide, and diphenyl sulfide was likewise formed even in the absence of nitrobenzene. These findings exclude the formation of diphenyl sul-fide by the ipso substitution of nitrobenzene by the phenylthiyl radical.…”

Section: Table IV Molecular Weights Of Thf-soluble Fractions Of Ab Comentioning

confidence: 66%

Devulcanization of nitrile butadiene rubber in nitrobenzene

Masaki

Ohkawara

Hirano

et al. 2004

J of Applied Polymer Sci

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Sulfur-crosslinked nitrile butadiene rubber (s-NBR) was found to be devulcanized when it was heated with nitrobenzene at 200°C for 3 h. The tetrahydrofuran (THF)-soluble fraction from s-NBR heated with nitrobenzene was purified by reprecipitation with THF/n-hexane, chloroform/ n-hexane, and THF/n-hexane systems and was then characterized by means of Fourier transform infrared (FTIR) spectroscopy, 1 H-NMR, gel permeation chromatography, dynamic thermogravimetry/differential thermal analysis (DTA), and differential scanning calorimetry (DSC). FTIR and 1 H-NMR results revealed that the THF-soluble fraction contained aromatic rings derived from nitrobenzene. Furthermore, the molecular weight of the THF-soluble fraction was much lower than that of the parent noncrosslinked poly(acrylonitrile-cobutadiene). Although the weight loss of THF-soluble fraction began at a lower temperature than that of the nonheated original nitrile butadiene rubber, the residual weight at 700°C tended to be higher for the former. This tendency became more marked with increasing time of heat treatment with nitrobenzene. The DSC-determined glass-transition temperature of the THF-soluble fraction was higher than that of the original s-NBR. To elucidate the devulcanization mechanism, we investigated two types of model reactions; one was the reaction of diphenyl disulfide with nitrobenzene, and the other was the reaction of polybutadiene with nitrobenzene. The former reaction, carried out at 250°C in diphenyl ether, yielded diphenyl sulfide with a loss of diphenyl disulfide and nitrobenzene. The use of a higher molar ratio of nitrobenzene to diphenyl disulfide resulted in a depression of diphenyl sulfide formation. The reaction of p-chloronitrobenzene with diphenyl disulfide also gave diphenyl sulfide. The reaction of polybutadiene with nitrobenzene at 200°C resulted in the backbone scission of the polymer. The THF-soluble solid product of the latter model reaction was found by FTIR and 1 H-NMR to contain aromatic rings derived from nitrobenzene. The devulcanization mechanism is discussed on the basis of a comparison of the results of the model reactions with those of the s-NBR devulcanization.

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Section: Table IV Molecular Weights Of Thf-soluble Fractions Of Ab Comentioning

confidence: 66%

Devulcanization of nitrile butadiene rubber in nitrobenzene

Masaki

Ohkawara

Hirano

et al. 2004

J of Applied Polymer Sci

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“…In addition, weight loss corresponding to the gas emission, increased as the amount of initiator increased. When 2,2′‐dithibis (benzothiazole) (DTB) was used as a radical initiator, which was reported Hay, the conversion increased as the amount of initiator increased. However, M w was relatively low, and the weight loss increased as the amount of initiator increased.…”

Section: Resultsmentioning

confidence: 91%

“…Therefore, rigorous polymerization condition is required to obtain high molecular weight polymer and to control the quality of polymer. Previously, new synthetic methods for the preparation of PPS have been reported, particularly, ring‐opening polymerization of c ‐PPS in the presence of initiator has received much attention at the end of 1990s . For example, Hay et al reported the selective synthesis of c ‐PPS hexamer through oxidative reaction of diphenyl disulfide under high dilute condition at room temperature .…”

Section: Introductionmentioning

confidence: 99%

Well‐Controlled Synthesis of Poly (phenylene sulfide) (PPS) Starting from Cyclic Oligomers

Horiuchi

Yamamoto²,

Kaiho

et al. 2015

Macromolecular Symposia

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Summary The mixture of cyclic PPS oligomers (c‐PPS) with more than 99% of purity, less than 15 ppm of metal content and more than 4 of repeating units was prepared by the nucleophilic substitution reaction between dichlorobenzene (DCB) and sodium sulfide (Na2S) in relatively dilute solution. Melt polymerization of the c‐PPS in the absence of initiator at high temperature resulted in P(c‐PPS) having high molecular weight, relatively narrow molecular weight distribution and extremely low weight loss at high temperature. Results from MALDI‐TOF‐MS, GPC and in‐situ ESR analysis of the polymerization intermediates suggested that the polymerization of c‐PPS proceeded by a sulfide exchanging polymerization. In addition, the sulfide exchanging polymerization of c‐PPS in the presence of bis(4‐substituted phenyl) sulfides (BPS‐X) such as bis(4‐aminopheny) sulfide (BPS‐NH2), bis(4‐carboxyphenyl) sulfide (BPS‐COOH), and bis(4‐chlorophenyl) sulfide (BPS‐Cl) produced end‐group modified and ring‐opened P(c‐PPS)s. Comparison of polymerization rate in the presence of BPS‐X suggested that the BPS‐X acted as both initiator and chain transfer agent, and the sulfide exchanging polymerization was accelerated by the addition of BPS‐NH2 and BPS‐COOH due to the activation of sulfide linkage through the substitution effect.

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“…As Ding reported, there are two kinds of active hydrogen in the bisphenol-like monomer 1, O-H, and N-H, and both of them have good activity in nucleophilic displacement reaction. 21 Polycondensation of compound 2 with excess of compound 1 afforded phenolate-terminated or aza-nitrogen-terminated oligomers by halo displacement. Subsequently, the intermediates facilely underwent nitro substitution with compound 3 to produce compounds 4a-4e in yields exceeding 92% (Table 1).…”

Section: Resultsmentioning

confidence: 99%

Phthalonitrile-functional multiple arylene ether nitrile-containing phthalazinone moiety: facile synthesis, curing, and properties

Liu

et al. 2014

High Performance Polymers

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This article discloses a series of processable multiple phthalazinone-based ether nitriles with various contents of phthalonitrile ends (compounds 4a–4e) and compares the cyclization feasibility of terminal phthalonitrile and pendant cyano group. Compounds 4a–4e were synthesized by facile polycondensation of excess 4-(4-hydroxyphenyl)-2,3-phthalazine-1-one (compound 1) with 2,6-difluorobenzonitrile (compound 2), followed by end-capping of 4-nitrophthalonitrile (compound 4). Their number-averaged molecular weights (M ns) and glass transitions can be well tailored by adjusting reactant ratio. Compounds 4a-4e are readily soluble in N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, N,N-dimethylformamide, and chloroform and hence can be processed either from their solutions or from melts. On mixing with trace amount of bis(4-aminophenyl)sulfone (compound 5), all oligomers were cross-linked to insoluble networks (compounds 6a-6d) except the high-molecular-weight 4e with the lowest phthalonitrile content. The phthalonitrile is found to be an effectively reactive site for cross-linking, whereas the pendant cyano group in multiple ether nitriles hardly undergoes any reaction confirmed by model reaction. Compounds 6a-6d maintain good structural integrity upon heating to 450°C and exhibit superior thermal stabilities compared with the known phthalazinone polymers. Compounds 6a-6d exhibit high flexural strength (98–111 MPa) as well as limited water absorption (2.2–2.7 wt%) under ambient conditions over a course of 30 days, permitting them to be promising candidates for organic electronics and automotives.

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Novel Synthesis of Poly(thioarylene)s via Reaction between Arenethiols and Bromo Compounds with a Free Radical Initiator

Cited by 13 publications

References 31 publications

Devulcanization of nitrile butadiene rubber in nitrobenzene

Devulcanization of nitrile butadiene rubber in nitrobenzene

Well‐Controlled Synthesis of Poly (phenylene sulfide) (PPS) Starting from Cyclic Oligomers

Phthalonitrile-functional multiple arylene ether nitrile-containing phthalazinone moiety: facile synthesis, curing, and properties

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