Polymer Science Faculty Research

Title

Measurement of Chain Transfer Constants to Polymer Using Oligomers and Model Compounds: Chain Transfer to Poly [11-(4'-cyanophenyl-4''-phenoxy) undecyl acrylate] in Radical Polymerization

Document Type

Article

Publication Date

8-18-2005

Abstract

The chain transfer constant to polymer (CP) for poly[11-(4‘-cyanophenyl-4‘ ‘-phenoxy)undecyl acrylate] was measured directly by the Mayo method by following the decrease in molecular weight at low monomer conversion by gel permeation chromatography of poly(methyl acrylate) generated in the presence of increasing amounts of 11-(4‘-cyanophenyl-4‘ ‘-phenoxy)undecyl propionate (CP = (6.62 ± 0.476) × 10-3) and 11-(4‘-cyanophenyl-4‘ ‘-phenoxy)undecyl isobutyrate (CP = (4.27 ± 0.858) × 10-3) as model compounds that mimic one repeat unit of the polymer and oligo[11-(4‘-cyanophenyl-4‘ ‘-phenoxy)undecyl acrylate] with nine repeat units (CP = (5.54 ± 0.608) × 10-3) synthesized by atom transfer radical polymerization. The mean chain transfer constant, CP = 5.48 × 10-3, was used to calculate the extent of branching (ρ) in poly[11-(4‘-cyanophenyl-4‘ ‘-phenoxy)undecyl acrylate] (DPn = 37) synthesized by conventional radical polymerization:  ρ = 0.0042−0.020 at 72−99% conversion, which corresponds to one branch per 6.4−1.4 chains, respectively, of 37 repeat units.

Publication Title

Macromolecules

Volume

38

Issue

19

First Page

8071

Last Page

8077