Short chain branching in poly(vinyl chloride)

Park, G. S.

doi:10.1002/vnl.730070205

Cited by 7 publications

(1 citation statement)

References 2 publications

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“…Hjertberg, et al (28), suggested that the chlorine atoms which result from head-to-head addition also attack polymer chains which result in the formation of internal double bonds or long chain branches. The mechanism of chain transfer to monomer is supported by the following findings: (i) the major part of the unsaturated chain ends has 1-chloro-2-alkene structure (26,40,41); (ii) the major part of the saturated chain ends consists of the 1.2-dichloro-alkane structure (23,26,27,40,41); and (iii) the presence of chloromethyl branches (22)(23)(24)(25)(42)(43)(44). Hence, the classical mechanism of the ordinary macroradical direct transfer to monomer is not valid.…”

Section: Chemical Reaction Typesmentioning

confidence: 90%

Suspension, bulk, and emulsion polymerization of vinyl chloride—mechanism, kinetics, and reactor modelling

Xie

Hamielec

Wood

et al. 1991

J. Vinyl Addit. Technol.

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A review of relevant microscopic processes, both chemical and physical, which occur during suspension, bulk and emulsion polymerization (both before and after pressure drop) is given. The state of the art of kinetic modelling of monomer consumption rate, reactor pressure, molecular weight and short and long chain branching development and polymer chain microstructure is illustrated. The effects of diffusion-controlled termination and propagation reactions and the significant decrease in initiator efficiency and decomposition rate constant at high monomer conversions on the relative rates of various chemical reactions are discussed. The application of temperature programming and semibatch operation are emphasized. Finally, attempts to model polymer particle morphology are described.

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Section: Chemical Reaction Typesmentioning

confidence: 90%

Suspension, bulk, and emulsion polymerization of vinyl chloride—mechanism, kinetics, and reactor modelling

Xie

Hamielec

Wood

et al. 1991

J. Vinyl Addit. Technol.

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On the preferential extraction of the more isotactic parts of PVC with acetone. A verification by ¹³C NMR analysis

Martínez¹,

Mijangos²,

Millán³

et al. 1986

Makromol. Chem.

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Acetone-soluble and -insoluble fractions were obtained from two different PVC samples: a polymer prepared in our laboratory at 60 "C using 2,2 '-azoisobutyronitrile (AIBN) as initiator (sample A) and a commercial polymer prepared at 70 "C (sample B). The content of isotactic, syndiotactic and heterotactic triads was accurately measured by high resolution 13C NMR. From the obtained data it follows that the isotactic triads accumulate preferably in the soluble fraction, the amount of which depends on the type of polymer. In agreement with earlier results, the soluble fraction is about 40% less stable than the insoluble fraction. The reasons for this behaviour are discussed in the light of the higher content of both isotactic triads and some defect structures, as found in the low molecular weight soluble extracts of PVC.

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Etude par ¹H NMR des groupements chlorométhyles du poly(chlorure de vinyle), 2. Etude par écho de spin et comparaison avec des modèles moléculaires

Llauro-Darricades¹,

Pétiaud

1989

Makromol. Chem.

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In order to assign all -CH,CI resonances observed by ' H NMR in poly(viny1 chloride), (PVC), a preliminary study of the diastereoisomers of molecular models for the groups CH2Cl-CHCI- [11] and ClCH,-CH< [IV] is used, in conjunction with spin echo experiments. The complex region [3,5 -4,O ppm] which corresponds to saturated -CH,CI chloromethyl protons is completely assigned. A separate evaluation of -CHCI-CH,CI[II], -CH,-CH,CI[III] and >CH-CH,CI [IV] is proposed and tested on raw PVC samples. The main interest of this ' H NMR determination is the fact that raw PVC can be used and that it gives the ratio [II]/[III] which is not accessible by I3C NMR on reduced samples.

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Short chain branching in poly(vinyl chloride)

Cited by 7 publications

References 2 publications

Suspension, bulk, and emulsion polymerization of vinyl chloride—mechanism, kinetics, and reactor modelling

Suspension, bulk, and emulsion polymerization of vinyl chloride—mechanism, kinetics, and reactor modelling

On the preferential extraction of the more isotactic parts of PVC with acetone. A verification by ¹³C NMR analysis

Etude par ¹H NMR des groupements chlorométhyles du poly(chlorure de vinyle), 2. Etude par écho de spin et comparaison avec des modèles moléculaires

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Short chain branching in poly(vinyl chloride)

Cited by 7 publications

References 2 publications

Suspension, bulk, and emulsion polymerization of vinyl chloride—mechanism, kinetics, and reactor modelling

Suspension, bulk, and emulsion polymerization of vinyl chloride—mechanism, kinetics, and reactor modelling

On the preferential extraction of the more isotactic parts of PVC with acetone. A verification by 13C NMR analysis

Etude par 1H NMR des groupements chlorométhyles du poly(chlorure de vinyle), 2. Etude par écho de spin et comparaison avec des modèles moléculaires

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On the preferential extraction of the more isotactic parts of PVC with acetone. A verification by ¹³C NMR analysis

Etude par ¹H NMR des groupements chlorométhyles du poly(chlorure de vinyle), 2. Etude par écho de spin et comparaison avec des modèles moléculaires