Seeded emulsion polymerization of butadiene. 1. The propagation rate coefficient

Verdurmen, E.M., Daohmen, E.H., Verstegen, J.M., Maxwell, I.A., German, A.L. and Gilbert, R.G. (1993) Seeded emulsion polymerization of butadiene. 1. The propagation rate coefficient. Macromolecules, 26 2: 268-275. doi:10.1021/ma00054a004

Author Verdurmen, E.M.
Daohmen, E.H.
Verstegen, J.M.
Maxwell, I.A.
German, A.L.
Gilbert, R.G.
Title Seeded emulsion polymerization of butadiene. 1. The propagation rate coefficient
Journal name Macromolecules   Check publisher's open access policy
ISSN 0024-9297
Publication date 1993-01
Sub-type Article (original research)
DOI 10.1021/ma00054a004
Volume 26
Issue 2
Start page 268
End page 275
Total pages 8
Place of publication Washington, DC, United States
Publisher American Chemical Society
Language eng
Formatted abstract
The kinetics of the emulsifier free seeded polymerization of butadiene at 60°C in Smith-Ewart interval III was investigated using sodium peroxodisulfate as initiator. The aim of this work was to measure the propagation rate coefficient (kp) of butadiene at 60°C in emulsion polymerization. Model-independent techniques to measure propagation rate coefficients like spatially intermitted polymerizations1-3 ("rotating sector" and "laser flash" photolysis) have not been used for butadiene so far since network formation prevents acquiring the necessary data from GPC. All experiments were conducted in the presence of tert-dodecylmercaptan, as is usual in industrial practice. The fractional conversion was based on gravimetrically calibrated on-line densitometry and was found to be highly accurate. By analogy with the well-known Ugelstad plots, the product of the propagation rate coefficient (kp) and the average number of radicals per particle (n̄) versus seed latex particle diameter clearly shows Smith-Ewart case I and case II regimes. From a constancy in values of kpn̄ (case II regime) in this plot, a value for kp could be calculated that was 3 times larger than the current literature value. It was found that negligible "thermal background initiation" is present in the butadiene system. Two linear regions in polymerization rate are observed in interval III. Model calculations are presented in excellent agreement with the experimental data. From these calculations a value of the rate coefficient for transfer to monomer, ktr, could be estimated.
Keyword Free-radical polymerization
Flash-initiated polymerization
Individual kinetic constants
Chain transfer agent
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Chemistry and Molecular Biosciences
Centre for Nutrition and Food Sciences Publications
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 17 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 0 times in Scopus Article
Google Scholar Search Google Scholar
Created: Mon, 07 Mar 2011, 15:58:55 EST