ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The overall rate of polymerization of styrene and isoprene with the heterogeneous allylsodium-sodium isopropoxide-sodium chloride (Alfin PP) system as initiator is reaction-controlled and is first order with respect to monomer and proportional to the amount of initiator present. The intrinsic viscosity of the product is independent of the monomer and initiator concentrations. The rate of styrene polymerization is independent of alkoxide concentration over a certain range, while the intrinsic viscosity increases with increasing alkoxide concentration. The activation energy of the overall rate is about 12 kcal./mole for styrene and 10 kcal./mole for isoprene. The simplest explanation of the kinetic results assumes initiation and termination steps involving the monomer. The distribution of molecular weights in Alfin polystyrene appears very broad. The kinetic features of this reaction bear a strong resemblance to those of the formation of isotactic polymers from the alkyl aluminum-titanium chloride system (Ziegler catalyst.)
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1959.1203913520
