Selective oxidation of poly(4‐methylstyrene)

Abstract

A range of new functional copolymers bearing aldehyde and carboxylic acid groups have been prepared by functionalization of poly(4-methylstyrene). These polymers have molecular weights from 2,000 to 16,500 and contain up to 20% aldehyde and up to 90% carboxylic acid groups. The reaction proceeds by selective catalytic oxidations with molecular oxygen or air in acetic acid/organic cosolvent mixtures in presence of cobalt acetate and sodium bromide or hydrogen bromide. The effects of reaction temperature, catalyst, co-solvents and oxygen partial pressure on the reaction are described. 0 1995 John Wiley & Sons, Inc.

Frustrated Reconstruction at the Surface of a Glassy Polymer

“…The surface of P4MS was oxidized using a modified version of procedures reported for the oxidation of substituted toluenes , and the bulk oxidation of P4MS (eq 1). , To avoid dissolution, minimize swelling, and thereby maximize selectivity for reaction at the polymer surface, we used a 1:1 (v/v) mixture of acetic acid and water as the solvent in these oxidations. Use of glacial acetic acid has been reported to swell poly(4-methylstyrene) . With sufficient rinsing, a cobalt-free (vide infra), hydrophilic surface was obtained, with a limiting advancing contact angle of water (pH 1) of 57°.…”

“…To assess the effect of oxidation of P4MS on its T g , we prepared macroscopic amounts of oxidized P4MS following a procedure similar to the one used in the surface modifications (eq 4). , One sample, oxidized to 33% conversion, contained an ∼2.7:1.0 ratio of the corresponding acid to aldehyde, as determined by 1 H NMR (Figure b, acetone- d 6 ) . A spectrum of the unmodified polymer (in chloroform- d 6 ) is provided in Figure a for comparison.…”

In situ Raman spectroscopic studies of polyvinyl toluene under laser‐driven shock compression and comparison with hydrostatic experiments

“…Atactic PVT , with weight average molecular weight (M w ) of 20 000, was obtained by thermal polymerization of vinyl toluene monomer using benzoyl peroxide as initiator, very similar to the reported method. [28] The polymer was precipitated with methanol and purified by repeated dissolution and precipitation. The PVT films of size 100 × 100 mm 2 were formed by melt casting method using appropriate spacer for the required thickness (200 μm).…”

Surface functionalization of polymer latex particles. II. Catalytic oxidation of poly(methylstyrene) latexes in the presence of cetyltrimethylammonium bromide

“…(2) The carboxylic acid chain rather than the primary hydrogens of the groups on the particle surface might interact with methyl group. [15][16][17] the cationic surfactant, thus reducing the total surface charge and the stability of the oxidized PMS latexes. The much broader particle size distribution after oxidation could be attributed to the uneven oxidation.…”