High-Pressure Kinetics of Oxidative Copolymerization of Styrene with -Methylstyrene

De, Priyadarsi; Sathyanarayana, D. N.

doi:10.1002/1521-3935(200211)203:15<2218::aid-macp2218>3.0.co;2-s

Cited by 13 publications

(21 citation statements)

References 20 publications

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“…However, AMS, as a comonomer, has been widely used in free radical co‐ and terpolymerizations. The polymerization processes and products have been extensively studied 3–7. These polymerizations are found to exhibit slow polymerization rates and produce low molecular weights, which are consistent with thermally reversible polymerization,8, 9 steric hindrance to successive placements of AMS units in the polymer chain,10 degradative chain transfer to AMS monomer,11–13 and to kinetic factors 10, 14, 15.…”

Section: Introductionmentioning

confidence: 84%

Degradation and initiation polymerization mechanism of α‐methylstyrene‐containing macroinitiators

Jiang

Deng

et al. 2010

J of Applied Polymer Sci

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Copolymers obtained from radical copolymerization of a-methylstyrene (AMS) and glycidyl methacrylate (GMA) behave as macroinitiators, when heated in the presence of a second monomer, giving rise to block copolymers. The relevant degradation and initiation polymerization mechanism of the macroinitiators were studied. Thermal depropagation of the macroinitiators generated monomers, identified by 1 H-NMR, photoionization mass spectroscopy and FT-IR. According to the results of structure analysis by GPC, ESR and NMR spectroscopy, the AMS-GMA (head-head) and AMS-AMS (head-head) bonds in the macroinitiators are easily scissored providing free radicals when the temperature is above 80C. The radicals lead to subsequent polymerization of the second monomer, and thereby block copolymers are formed.

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Section: Introductionmentioning

confidence: 84%

Degradation and initiation polymerization mechanism of α‐methylstyrene‐containing macroinitiators

Jiang

Deng

et al. 2010

J of Applied Polymer Sci

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“…All polyperoxides were prepared by oxidative polymerization as reported elsewhere 5 and characterized by proton and carbon-13 nuclear magnetic resonance spectroscopy ( 1 H and 13 C NMR, respectively) recorded on a Bruker AC-F 200 MHz spectrometer in CDCl 3 and CH 2 Cl 2 (D 2 O external lock), respectively.…”

Section: Methodsmentioning

confidence: 99%

“…5 The activation energies for thermal degradation in solution are 45-50% lower than those in the solid state. 5 The low activation energies for thermal degradation in solution suggests that uniform heat transfer to the polymer molecules favor decomposition in solution compared with the solid state. 10 The relative stability of the polyperoxides can be compared from the activation energies for thermal degradation data.…”

Section: Determination Of Specific Scission Rate Coefficientmentioning

confidence: 99%

“…The activation energies for thermal degradation in the solid state were 39.0, 36.8, and 43.7 kcal mol Ϫ1 for PPMSP, PPBrSP, and PPTBSP, respectively. 5 The activation energies for thermal degradation in solution are 45-50% lower than those in the solid state. 5 The low activation energies for thermal degradation in solution suggests that uniform heat transfer to the polymer molecules favor decomposition in solution compared with the solid state.…”

Section: Determination Of Specific Scission Rate Coefficientmentioning

confidence: 99%

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Thermal degradation kinetics of para‐substituted poly (styrene peroxide)s in solution

Chattopadhyay

Madras

et al. 2002

J of Applied Polymer Sci

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ABSTRACT:The thermal degradation of three polymeric peroxides of styrene monomers with substituents in the para position was studied at various temperatures (65, 75, 85, and 95°C). A continuous distribution model was used to evaluate the rate coefficients for the random-chain and chain-end scission degradation from the evolution of molecular weight distributions with time. The activation energy determined from the temperature dependence of the rate coefficients was in the range 18 -22 kcal mol Ϫ1 . This result suggests that the thermal degradation of polyperoxide is controlled by the dissociation of the O-O bonds in the polymer backbone.

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“…In the literature, the effect of oxygen pressure on the oxidation of styrene (St) [16], a-methyl styrene (AMS) [17], and oxidative copolymerization [18] of St with AMS has been studied in detail. However, there is no systematic study for the kinetics of oxidative polymerization of styrenic monomers to understand the effect of a-substitution.…”

Section: Introductionmentioning

confidence: 99%

Kinetic and thermochemical study of the oxidative polymerization of α-substituted styrenes

Pal

Ghorai

2012

Polym. Bull.

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This article reports a systematic kinetic study on the oxidative polymerization of a-substituted styrene monomers such as styrene (St), a-methylstyrene (AMS), 4-chloro a-methylstyrene (CAMS), and a-phenylstyrene (APS) in the presence of 2,2 0 -azobisisobutyronitrile as a free radical initiator at 100 psi oxygen pressure and 40-50°C in toluene. The rate of oxidative polymerization follows the order:Theoretical calculations have been performed using density functional theory to support the order of oxidative polymerization rates. In addition, the synthesis and characterization of poly(4-chloro a-methylstyrene peroxide) (PCAMSP) is reported here for the first time. Elemental analysis and nuclear magnetic resonance spectroscopy confirm the alternating copolymer structure of PCAMSP with -O-O-bonds in the main chain. Thermal degradation studies using differential scanning calorimeter and thermogravimetric analysis reveal that PCAMSP degrades highly exothermically and the average enthalpy of degradation at various heating rates is found to be 48.7 ± 0.6 kcal/mol, which is of the same order reported for other vinyl polyperoxides.

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High-Pressure Kinetics of Oxidative Copolymerization of Styrene with -Methylstyrene

Cited by 13 publications

References 20 publications

Degradation and initiation polymerization mechanism of α‐methylstyrene‐containing macroinitiators

Degradation and initiation polymerization mechanism of α‐methylstyrene‐containing macroinitiators

Thermal degradation kinetics of para‐substituted poly (styrene peroxide)s in solution

Kinetic and thermochemical study of the oxidative polymerization of α-substituted styrenes

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