The effect of polyester plasticizer of differing acid number on the properties of PVC compositions, to be used for electric insulation purposes, is investigated. It is established that the acid number affects both the temperature dependence of the specific bulk resistance in vitreous and highly elas
Investigating the effects of polymer chemistry on activity of biocatalytic plastic materials
โ Scribed by Scott J. Novick; Jonathan S. Dordick
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 211 KB
- Volume
- 68
- Category
- Article
- ISSN
- 0006-3592
No coin nor oath required. For personal study only.
โฆ Synopsis
The affects of polymer chemistry on the organic solvent activity of โฃ-chymotrypsin-containing biocatalytic plastic materials are investigated in this study. To incorporate โฃ-chymotrypsin into the polymer, the enzyme is first acryloylated, then solubilized into organic solvents via hydrophobic ion paring with surfactant molecules. Once in the organic solvent, a vinyl monomer and crosslinker are added and copolymerized with the enzyme. Due to the intimate contact between the enzyme and the resulting polymer network, the polymer chemistry plays an important role in the activity of these biocatalytic materials. The chemical composition of the monomer/polymer has the greatest effect on catalytic activity. The activity spans a range of 100-fold and appears to correlate with the hydrophilicity of the monomer, with the lowest activity exhibited for poly(methyl methacrylate) and the highest for poly(2-hydroxyethyl methacrylate). The effect of the chemical structure of the monomer/polymer appears to be an intrinsic kinetic effect, whereas other polymer chemistry conditions investigated, including crosslinker concentration and length and ratio of solvent:monomer during synthesis, appear to effect the rate of substrate diffusion, thereby affecting observed enzyme activity. Changes in the conditions of polymer synthesis can cause as much as a 20-fold change in activity for a given polymeric material. This is most likely due to an increase in the porosity of the materials, and thus a relaxation of diffusional limitations.
๐ SIMILAR VOLUMES
A method to improve the durability of electrically conductive polyacrylonitrile (PAN) fibers treated with the Cu x S method was developed in this article. The influence of pretreatment with activators and posttreatment with polysulfide on the durability was studied, and the mechanism was proposed. T