English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

General physical mcxiels of the migration of low molecular weight species in polymer matrices are needed to provide a basis for the efficient reg’dlation of plastics used in food contact applications. This report presents the first year's progress on a project containing both theoretical and experimental elements aimed at producing such models. Using a modified equation of state approach, models have been developed for estimating the equilibrium partitioning of a diffusant in a polymer at a tem.peratijre above its glass transition in contact with a finite volume of solvent. Some possible new approaches to a diffusion theory based on volume fluctuations were outlined. Model calculations using diffusion equations have been made for the extraction of additives from polymers with concomitant solvent absorption and for finding a constant extraction temperat'ure equivalent to migration 'under varying temperature conditions. 'The migration of an oligomer, ^'Relabeled ocradecane, from high density linear polyethylene lato various solvents at different temperatures was measured in order to elucidate the effects of thickness, temperature, concentration and solvent. Deviations from ideal Fickean -kinetics la the experimental results may be attributed to the strong influence of s’welling of the polymer on the migration rates and to the possible incorporation of a small portion of the oligomer in the crystalline phase of the polymer.

Models for the migration of paraffinic additives in polythylene