ISSN:
0449-2978
Schlagwort(e):
Physics
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
Batch polymerizations of vinyl acetate were conducted at 60°C and 72°C, and rate constants for branching were established from the variation of M̄n and M̄w with extent of conversion. The calculated branching densities (branch points per polymer molecule) are slightly higher at 72°C for all conversions. Selected samples were saponified and reacetylated to determine the amount of branching through the acetate group. Changes in M̄n, M̄w, and [η] indicate 63%, 75%, and 70%, respectively, of saponificable branches. These percentages are independent of branching density in the original polymer. Molecular weights extrapolated to zero conversion appear to be unchanged by saponification and reacetylation, showing that short chain branching through the acetate group is absent, or at least very infrequent.
Zusätzliches Material:
6 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pol.1969.160071107
