Comparative Trends of Copolymerizations Involving Alpha Methyl Styrene at Elevated Temperatures 1*

McManus, Neil T.; Lona, Liliane Maria Ferrareso; Penlidis, Alexander

doi:10.1081/pre-120016298

Cited by 7 publications

(4 citation statements)

References 9 publications

(16 reference statements)

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“…The feed compositions do not match the terpolymer compositions (the BA and MMA fractions in the terpolymer are always higher than those in the original feed), and this makes the system different from standard multicomponent polymerizations exhibiting azeotropic feed compositions. This is related to the fact that the polymerization is carried out above the ceiling temperature of AMS and to the resulting complexities in the polymerization kinetics 11, 12…”

Section: Resultsmentioning

confidence: 99%

“…This is related to the fact that the polymerization is carried out above the ceiling temperature of AMS and to the resulting complexities in the polymerization kinetics. 11,12 The method of analysis using 1 H-NMR spectra was convenient for the estimation of the terpolymer compositions for multiple samples. It is conceded that this method is not ideal because the expressions imply some correlation between the measured levels of BA and MMA, and this compounds any error normally associated with NMR analysis.…”

Section: Resultsmentioning

confidence: 99%

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NMR analysis of butyl acrylate/methylmethacrylate/α‐methyl styrene terpolymers

McManus

Penlidis

2006

J of Applied Polymer Sci

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Composition analysis for butyl acrylate (BA)/ methyl methacrylate (MMA)/a-methyl styrene terpolymers was carried out by NMR spectroscopy methods. 1 H-NMR was used primarily for this analysis, but because the method did not provide independent measurements for the BA and MMA fractions, the terpolymer composition analysis was open to higher than normal levels of uncertainty. Supplementary analyses were made with quantitative

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

NMR analysis of butyl acrylate/methylmethacrylate/α‐methyl styrene terpolymers

McManus

Penlidis

2006

J of Applied Polymer Sci

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“…The literature indicates that the composition (but not the kinetics) of MMA−BA and MMA−styrene − copolymers formed by radical polymerization are adequately described by terminal model reactivity ratios. Reported reactivity ratios for AMS−styrene and AMS−BA , show significant temperature dependence which is attributed to the reversibility of propagation. Reactivity ratios for copolymerizations of BA with MAN have not been reported.…”

Section: Resultsmentioning

confidence: 99%

“…When our analysis was initiated, the only reported reactivity ratio data for the AMS-BA system was that of McManus et al 68 Their work indicated a very low value for r AMS particularly at high temperatures (Table 11). If r AMS is low, then higher values of the transfer constants can be chosen to predict the observed chain end composition and molecular weight.…”

Section: P(a|s) )mentioning

confidence: 99%

Binary Copolymerization with Catalytic Chain Transfer. A Method for Synthesizing Macromonomers Based on Monosubstituted Monomers

et al. 2005

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With appropriate choice of conditions, copolymerization of monosubstituted monomers [CH2CHX: e.g., styrene, butyl acrylate (BA)] in the presence of small amounts of an α-methylvinyl monomer [CH2C(CH3)Y: e.g., α-methylstyrene (AMS), methyl methacrylate (MMA), methacrylonitrile (MAN)] and a cobaloxime as chain transfer catalyst provides a route to macromonomers that are composed largely of the monosubstituted monomer and yet have a chain end derived from the α-methylvinyl monomer (−CH2−C(CH2)Y). The various factors (temperature, concentrations, type of cobaloxime, types of monomer) that influence molecular weight and end group purity and the importance of the various side reactions that may complicate the process are described. Macromonomer purity is enhanced by increasing the concentration of the α-methylvinyl monomer and reducing the cobaloxime concentration. It also depends on the structure of the cobaloxime, increasing in the series where the ligands are derived from dimethyl glyoxime < diethyl glyoxime ∼ diphenyl glyoxime, and the α-methylvinyl monomer, increasing in the series where Y is CO2R < CN < Ph. For styrene−AMS copolymerization, macromonomer purity (the fraction of AMS-derived ends) was enhanced by increasing the reaction temperature. For BA−AMS copolymerization, macromonomer purity was enhanced by decreasing the reaction temperature. However, it is necessary to use a high reaction temperature to limit the extent of macromonomer copolymerization that occurs as a side reaction at high monomer conversion. High purity, AMS terminal BA macromonomers can be prepared by BA−AMS copolymerization at 125 °C with as little as 2 mol % AMS. We also show how the overall composition, molecular weight, and end group functionality of copolymers formed in the presence of a chain transfer agent can be predicted using classical statistics and point out some problems with previous treatments. Analytical expressions which describe zero conversion binary copolymerization in the presence of a transfer agent are derived and successfully applied to the above-mentioned system. The effective transfer constants of cobaloxime transfer catalysts are reported. Those observed in copolymerizations of vinyl and α-methylvinyl monomers are reduced with respect to values observed in homopolymerization of α-methylvinyl monomers because of reversible consumption of the cobalt complex as an adduct to the vinyl monomer. Transfer constants of macromonomers with AMS end groups in styrene polymerization at 120 °C are in the range 0.11−0.15. At lower temperatures (80 °C), macromonomer copolymerization dominates over chain transfer and the effective transfer constant is ∼0.

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Binary copolymerization with full depropagation: A study of methyl methacrylate/α‐methyl styrene copolymerization

Leamen

McManus

Penlidis

2005

J. Polym. Sci. A Polym. Chem.

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The kinetics of the copolymerization of α‐methyl styrene and methyl methacrylate (MMA) have been revisited for the bulk system. Reactivity ratios and other kinetic parameter estimates based upon a copolymerization model developed by Kruger et al. (Makromol Chemie 1987, 188, 2163–2175) have been determined for a range of temperatures (60–140 °C). An interesting phenomenon has been uncovered, which shows that there is a distinct difference in copolymer composition predicted by the model when compared with experimental data at feed ratios of MMA below a critical value. This deviation also appears to be influenced by the reaction temperature. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3868–3877, 2005

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Comparative Trends of Copolymerizations Involving Alpha Methyl Styrene at Elevated Temperatures 1*

Cited by 7 publications

References 9 publications

NMR analysis of butyl acrylate/methylmethacrylate/α‐methyl styrene terpolymers

NMR analysis of butyl acrylate/methylmethacrylate/α‐methyl styrene terpolymers

Binary Copolymerization with Catalytic Chain Transfer. A Method for Synthesizing Macromonomers Based on Monosubstituted Monomers

Binary copolymerization with full depropagation: A study of methyl methacrylate/α‐methyl styrene copolymerization

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