ISSN:
0887-624X
Keywords:
bicyclic ether
;
cyclic acetal
;
copolymerization
;
transacetalization
;
telechelics
;
promesogenic
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Copolymers of 7-oxabicyclo[2.2.1] heptane (B) (and of its 2-methyl derivatives) with 1,3-dioxane (D) were obtained by cationic copolymerization initiated with benzoylium hexafluoroantimonate. Structure of copolymers was determined by 1H- and 13C-NMR. The proportion of the acetal bonds in copolymers was additionally confirmed in studies of the products of hydrolysis (only the acetal bonds hydrolyze). D is unable to homopolymerize for the thermodynamic reasons and therefore mostly pseudoperiodic copolymers (-DBx-)y are formed. Nevertheless, the reshuffling reactions are responsible for the appearance of “wrong” units. These are: the separate oxymethylene and oxy-1,3-propylene units (P, subunits of D) located between two B units. Only the acetal bonds are cleaved in the acidic hydrolysis with dilute HCl. This gives the promesogenic telechelic oligomers of mostly HO-P-Bx-OH structure. This article is the first to describe successful cationic copolymerization of a cyclic acetal with a cyclic ether. Moreover, the inability of D to homopolymerize gives the thermodynamic basis of the pseudoperiodic copolymer formation. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1733-1742, 1997
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
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