Acrylate Methacrylate Copolymers Research Articles

Methyl-ketone production by Ca-alginate/Eudragit RL entrapped spores of Penicillium roqueforti

The synthesis of methyl-ketone from octanoic acid, sodium salt by Ca-alginate entrapped spores was studied. Alginate gel beads enclosed by an acrylate-methacrylate copolymer (Eudragit RL) were used due to their enhanced mechanical stability. The measurement of the carbon dioxide evolved showed that octanoic acid quantitatively yields 2-heptanone as the sole methyl-ketone. The reaction could be performed in a reactor with a nonbuffered medium by maintaining the pH at a constant value, 5.5. The determination of the volume of the hydrochloric acid solution added during the course of the biotransformation process allowed a continuous monitoring of the reaction progress performed in an aerated, stirred-tank reactor.

Structure and permeability of composite films of two analogous acrylate methacrylate copolymers.

Two analogous acrylate methacrylate copolymers, A and B, which form films with compact surface zones (skins) have been layered into composite films AB and BA. Electron micrographs of the composite film internal structure revealed a porous asymmetry; the mean pore size in layer A was 2.4 +/- 0.3 microns, and that in layer B 0.71 +/- 0.06 microns. The actual surface pores were considerably smaller than the internal pores, below the limit of resolution of the electron microscope. AB (layer A accepting the permeant first) was 17 times more permeable to the solute, urea, than BA. Exposure of the film surfaces to solvent vapor before layering caused dissolution of the "skin" in component layers; resulting composite films were therefore more permeable than theoretical expectation.

Swellability of cast films of an acrylate-methacrylate copolymer in aqueous solutions of certain permeants and concentration-dependent permeability

Abstract Swellability of cast films of an acrylate-methacrylate copolymer in aqueous solutions of certain permeants has been determined by fluid uptake experiments. Swellability increased linearly with urea concentrations but decreased with concentrations of ionic permeants, sodium chloride and sulfacetamide sodium. Film permeability coefficients for urea also increased linearly with its concentration whereas those for the ionic permeants increased with increase in their concentrations up to 5%, but decreased at concentrations 5% to 10% w/v. This finding can be associated with the swellability behavior of the films.

Pyrolysis Gas Chromatographic Evaluation of Sequence Distributions in Acrylate–Methacrylate Copolymers

Sequence distributions of acrylate–methacrylate copolymers were evaluated with Yamaguchi–Yokoyama’s pyrogram. The diad concentration ratio of P2(acrylate–acrylate) to P2(acrylate–methacrylate) was empirically estimated by the peak area ratio of related acrylate monomer to dimer. Sequence distributions of diad in the ethyl acrylate (EA)–butyl methacrylate (BMA) copolymer, synthesized under different conditions, were comparatively evaluated. Their sequence distributions were also possible to evaluate by the peak area ratio of EA–EA dimer to EA–BMA dimer on their pyrogram. The results from the former method were in good agreement with those from the latter method. Furthermore, the method principally the same as the former was applied to evaluate the diad concentration ratios in EA–butyl acrylate (BA)–BMA terpolymers.

Recent work on the thermal degradation of acrylate and methacrylate homopolymers and copolymers

Abstract

Thermal decomposition of methacrylate-acrylate copolymers

Thermal decomposition of methacrylate-acrylate copolymers