Effect of Process Design/Operation on the Steady-State Operability of a Methyl Methacrylate Polymerization Reactor

1999 ◽  
Vol 38 (12) ◽  
pp. 4790-4804 ◽  
Author(s):  
Andrea Silva-Beard ◽  
Antonio Flores-Tlacuahuac
Keyword(s):  
Steady State ◽  
Methyl Methacrylate ◽  
Process Design ◽  
Methyl Methacrylate Polymerization ◽  
Polymerization Reactor

Methyl methacrylate polymerization involving a cobalt ortho-iminobenzosemiquinone complex: Determination of the chain transfer constant

2015 ◽  
Vol 56 (3) ◽  
pp. 267-275 ◽  
Author(s):  
E. V. Kolyakina ◽  
Yu. E. Ovchinnikova ◽  
I. D. Grishin ◽  
A. I. Poddel’skii ◽  
D. F. Grishin
Keyword(s):  
Methyl Methacrylate ◽  
Chain Transfer ◽  
Transfer Constant ◽  
Methyl Methacrylate Polymerization ◽  
Chain Transfer Constant

On the Mechanism of Radical Polymerization of Methyl Methacrylate with Dithiobenzoic Acid as Mediator

2006 ◽  
Vol 59 (8) ◽  
pp. 549 ◽  
Author(s):  
Duc Hung Nguyen ◽  
Philipp Vana
Keyword(s):  
Methyl Methacrylate ◽  
Induction Period ◽  
Hydrogen Abstraction ◽  
Ester Group ◽  
Reaction Scheme ◽  
Ionization Mass ◽  
Controlled Polymerization ◽  
Induction Periods ◽  
Methyl Methacrylate Polymerization ◽  
Raft Agent

Dithiobenzoic acid (DTBA) induces controlled polymerization behaviour in methyl methacrylate polymerization at 60°C, accompanied by a pronounced induction period of several hours. DTBA is partially transformed during this induction period into a dithioester with a tertiary ester group moiety, which constitutes an efficient reversible addition–fragmentation chain transfer (RAFT) agent. The transformation reaction is proposed to proceed via a hydrogen abstraction from DTBA by radicals and subsequent termination of the formed phenylcarbonothioylsulfanyl radical with propagating radicals. The proposed reaction scheme was implemented into a computer model, by which the rate coefficient of the hydrogen abstraction from DTBA and of the reinitiation of the intermediate phenylcarbonothioylsulfanyl radical was estimated. The model is in agreement with all of the species observable by electrospray ionization mass spectrometry, with the extent of the experimental induction periods, and with the absolute concentrations of dithioesters that act as efficient RAFT agents during the polymerization. A protocol that uses a cocktail of initiators is introduced, by which the induction period in DTBA-mediated polymerization is effectively eliminated.

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