ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The composition and monomer unit sequence distribution of copolymers of p-chlorostyrene (p-CST) with citraconic (α-methylmaleic) anhydride (CA) prepared in methyl ethyl ketone (MEK) at 50,0 ± 0,1°C were determined over a range of comonomer feed mole fractions using 13C NMR spectroscopy. The monomeric units in these copolymers were found to display a mild tendency to alternate, which increased as the mole fraction of CA in the feed increased. The existence of a 1:1 charge-transfer complex formed between p-CST and CA in the feed was confirmed via UV spectroscopy and the equilibrium constant for complex formation determined to be 0,10 ± 0,04 L/mol in MEK at ambient temperature. The terminal, penultimate, complex-participation and complex-dissociation models were each tested for applicability to the mechanism of copolymerisation for this comonomer system. On the basis of copolymer composition data, the penultimate, complex-participation and complex-dissociation models were each found to provide an adequate description of the mechanism of copolymerisation in the comonomer system via non-linear least squares methods. An analysis of the comonomer unit sequence distributions for these semi-alternating copolymers and the application of reactivity ratio related test functions to this data allowed applicability of the four models under investigation to be separated more explicitly, with the complex-dissociation model providing the best fit to the data.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1994.021950309
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