Effect of Monomer Feed Rate on Chain Transfer to Polymer in Semibatch Emulsion Polymerization of Vinyl Acetate Studied by NMR Spectroscopy

2000 ◽  
Vol 33 (14) ◽  
pp. 5048-5052 ◽  
Author(s):  
David Britton ◽  
Frank Heatley ◽  
Peter A. Lovell
Keyword(s):  
Nmr Spectroscopy ◽  
Emulsion Polymerization ◽  
Vinyl Acetate ◽  
Feed Rate ◽  
Chain Transfer ◽  
Monomer Feed

Chain Transfer to Polymer in Free-Radical Bulk and Emulsion Polymerization of Vinyl Acetate Studied by NMR Spectroscopy

1998 ◽  
Vol 31 (9) ◽  
pp. 2828-2837 ◽  
Author(s):  
David Britton ◽  
Frank Heatley ◽  
Peter A. Lovell
Keyword(s):  
Free Radical ◽  
Nmr Spectroscopy ◽  
Emulsion Polymerization ◽  
Vinyl Acetate ◽  
Chain Transfer

scholarly journals Poly(vinyl acetate-co-ethylene) particles prepared by surfactant-free emulsion polymerization in the presence of a hydrophilic RAFT/MADIX macromolecular chain transfer agent

2020 ◽  
Vol 11 (46) ◽  
pp. 7410-7420
Author(s):  
James Delorme ◽  
Olivier Boyron ◽  
Pierre-Yves Dugas ◽  
Pierre-Emmanuel Dufils ◽  
D. James Wilson ◽  
...  
Keyword(s):  
Emulsion Polymerization ◽  
Vinyl Acetate ◽  
Chain Transfer ◽  
Chain Transfer Agent ◽  
Macromolecular Chain

Poly(vinyl acetate-co-ethylene) latexes are prepared under a broad range of conditions by emulsion polymerization in the presence of a hydrophilic RAFT/MADIX macromolecular chain transfer agent.

scholarly journals Crosslinking in Semi-Batch Seeded Emulsion Polymerization: Effect of Linear and Non-Linear Monomer Feeding Rate Profiles on Gel Formation

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 596
Author(s):  
Chang Liu ◽  
Amit K. Tripathi ◽  
Wei Gao ◽  
John G. Tsavalas
Keyword(s):  
Emulsion Polymerization ◽  
Feed Rate ◽  
Monomer Concentration ◽  
Butyl Methacrylate ◽  
Gel Formation ◽  
Seeded Emulsion Polymerization ◽  
Linear Profile ◽  
Gel Fraction ◽  
Non Linear ◽  
Monomer Feed

Waterborne latex is often called a product-of-process. Here, the effect of semi-batch monomer feed rate on the kinetics and gel formation in seeded emulsion polymerization was investigated for the copolymerization of n-butyl methacrylate (n-BMA) and ethylene glycol dimethacrylate (EGDMA). Strikingly, the gel fraction was observed to be significantly influenced by monomer feed rate, even while most of the experiments were performed under so-called starve-fed conditions. More flooded conditions from faster monomer feed rates, including seeded batch reactions, counterintuitively resulted in significantly higher gel fraction. Chain transfer to polymer was intentionally suppressed here via monomer selection so as to focus mechanistic insights to relate only to the influence of a divinyl monomer, as opposed to being clouded by contributions to topology from long chain branching. Simulations revealed that the dominant influence on this phenomenon was the sensitivity of primary intramolecular cyclization to the instantaneous unreacted monomer concentration, which is directly impacted by monomer feed rate. The rate constant for cyclization for these conditions was determined to be first order and 4000 s−1, approximately 4 times that typically observed for backbiting in acrylates. This concept has been explored previously for bulk and solution polymerizations, but not for emulsified reaction environments and especially for the very low mole fraction divinyl monomer. In addition, while gel fraction could be dramatically manipulated by variations in linear monomer feed rates, it could be markedly enhanced by leveraging non-linear feed profiles built from combination sequences of flooded and starved conditions. For a 2 h total feed time, a fully linear profile resulted in 30% gel while a corresponding non-linear profile with an early fast-feed segment resulted in 80% gel.

Reversible addition–fragmentation chain transfer synthesis and micellar characteristics of biocompatible amphiphilic poly(vinyl acetate)-graft-poly(N-vinyl-2-pyrrolidone) copolymers

2014 ◽  
Vol 53 ◽  
pp. 109-117 ◽  
Author(s):  
Leonard Ionut Atanase ◽  
Jérémy Winninger ◽  
Christelle Delaite ◽  
Gérard Riess
Keyword(s):  
Vinyl Acetate ◽  
Chain Transfer ◽  
Reversible Addition

Pseudoliving polymerization of vinyl acetate mediated by reversible addition-fragmentation chain-transfer agents

2011 ◽  
Vol 53 (7-8) ◽  
pp. 437-447 ◽  
Author(s):  
E. V. Chernikova ◽  
V. V. Yulusov ◽  
K. O. Mineeva ◽  
V. B. Golubev ◽  
E. S. Garina
Keyword(s):  
Vinyl Acetate ◽  
Chain Transfer ◽  
Reversible Addition ◽  
Transfer Agents

Continuous emulsion polymerization of vinyl acetate. Part I: Experimental studies

1980 ◽  
Vol 58 (1) ◽  
pp. 48-55 ◽  
Author(s):  
C. Kiparissides ◽  
J. F. Macgregor ◽  
A. E. Hamielec
Keyword(s):  
Emulsion Polymerization ◽  
Vinyl Acetate ◽  
Experimental Studies
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