The Chemical Modification of Polyvinyl Chloride

Naqvi, Mohammad Kazim

doi:10.1080/07366578708078822

Cited by 8 publications

(2 citation statements)

References 116 publications

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“…We then optimized reaction conditions by varying the reaction time, catalyst loading, temperature and silane source (Table S1, entries [7][8][9][10][11][12][13][14]. From these experiments, we conclude that a 1 mol % loading of 1 b at 40-60 °C in the presence of Et 3 SiH in C 6 H 5 Br for at least 24 h are optimal conditions.…”

Section: Resultsmentioning

confidence: 99%

“…[6] Hydrodechlorination (HDC, Scheme 1) of PVC has been known since the 1950s, when Cotman reported its reduction with LiAlH 4 in refluxing THF. [7] Although this reaction is mainly interesting for analytical purposes (i. e. the determination of branching), [8] a modified version using milder and safer silanes has recently attracted attention in the context of plastic waste management. [9] Alternatively, tandem dehydrochlorination (DHC)/hydrogenation under H 2 pressure yields similar polyethylene-like (PE) polymers.…”

Section: Introductionmentioning

confidence: 99%

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Poly(vinyl chloride) Dechlorination Catalyzed by Zirconium

Normand,

Wu,

Régnier

et al. 2024

Chemistry A European J

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Poly(vinyl chloride) undergoes dechlorination in the presence of triethylsilane (Et3SiH) and a catalytic amount of [Cp2Zr(NPh2)][CH3B(C6F5)3] (1b) at 40‐80 °C, with up to 91 % efficiency. Stoichiometric reactivity studies conducted on cyclohexyl chloride as a model suggest that 1b dechlorinates PVC by initial chloride abstraction, followed by hydride transfer to the cationic PVC chain from Et3SiH. Consumer items such as pipe fitting, vinyl disc or electric cable insulation undergo either dechlorination or hydrosilylation of the carbonyl‐containing copolymer (polyvinyl acetate) or plasticizer (phthalate).

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Poly(vinyl chloride) Dechlorination Catalyzed by Zirconium

Normand,

Wu,

Régnier

et al. 2024

Chemistry A European J

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Configurational and conformational control of chemical modification and thermal degradation of poly(vinyl chloride)

Millán

Martínez

Mijangos

et al. 1989

Makromolekulare Chemie. Macromolecular Symposia

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In the light of some earlier works on nucleophilic substitution on poly(viny1 chloride) (PVC) in solution, a conformational mechanism is proposed. It considers the T T isotactic diad conformation t o be the only reactive species and the reaction to be controlled by the conformational equilibria that make such conformation available. A s a result all the isotactic and the heterotactic triads are capable of reacting provided that they adopt the GTTG-and the GTTT c o n f o r m a t i o n , r e s p e c t i v e l y .Since the replacement of a definite fraction of isotactic triads, which are assumed t o be of the GTTG-conformation, results i n an enhanced thermal and photochemical stability, the lability of some chlorines at such triads is proved. Further arguments in favour o f the conformational mechanism are afforded through recent results of i) substitution studies in the melt and i n aqueous suspension with phase transfer catalysts, ii) accurate 1 3~ N M R measurements of triad variation with degree o f substitution.

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Stereoselective nucleophilic substitution of poly(vinyl chloride) with potassium 4‐acetamidothiophenolate

Martínez

Millán

2004

J. Polym. Sci. A Polym. Chem.

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The nucleophilic substitution reaction of poly(vinyl chloride) (PVC) with potassium 4‐acetamidothiophenolate was performed in a cyclohexanone solution. The quantitative microstructural analysis, as a function of the conversion, was followed by 13C NMR spectroscopy. Through a comparison of the microstructural changes with the degree of substitution, a small fraction of mmr tetrads was found to react occasionally with the central chlorine of the mr triad instead of the mm, such as for sodium benzenethiolate (NaBT). This conclusion was confirmed by Fourier transform infrared results. However, unlike NaBT, the evolution of the glass‐transition temperature (Tg) with the degree of conversion changed with the degree of substitution similarly to the ratio of the extents to which mmr and rrmr structures intervened in the substitution reaction. From these studies, it followed that the specific interactions due to the polar nature of the nucleophile enhanced the molecular‐microstructure‐based mechanisms, which were responsible for Tg. Such a novel quantitative correlation, compared with more tentative ones obtained previously, presents valuable insight into the role of the stereochemical microstructure in the glass‐transition process in PVC. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1857–1867, 2004

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The Chemical Modification of Polyvinyl Chloride

Cited by 8 publications

References 116 publications

Poly(vinyl chloride) Dechlorination Catalyzed by Zirconium

Poly(vinyl chloride) Dechlorination Catalyzed by Zirconium

Configurational and conformational control of chemical modification and thermal degradation of poly(vinyl chloride)

Stereoselective nucleophilic substitution of poly(vinyl chloride) with potassium 4‐acetamidothiophenolate

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