ISSN:
0098-1273
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The kinetics of the quaternization of poly(4-vinyl pyridine) with 1-bromopropane in sulfolane has been studied in the temperature range 308-348°K with data points covering the whole conversion range. The results have been analyzed according to the neighbouring-group model with rate constants k0, k1, and k2 for reaction of pyridyl groups with zero, one, and two already reacted neighbors. Allowing for limiting reaction at about 95%, the experimental results substantiate the model with K = k1/k0 = 0.80 ± 0.03, and L = k2/k0 = 0.37 ± 0.03, which are independent of temperature. The temperature dependence of k0 values gives an activation energy of 66.22 ± 4.20 kJ mol-1. It is still not possible to decide whether steric or electrostatic factors are responsible for K and L values less than unity. Other systems are mentioned where side reactions occur.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1977.180150209
