The present invention relates to the field of foamable compositions having an ethylene-based co-polymer containing a carbon monoxide co-monomer.

A critical overview of publications on applications of supercritical fluids in polymer formation, modification and processing is presented. The review is focused on publications that appeared in 2014 only with the intent of providing an in-depth look at the activity in the most recent year to gain insights on the more recent trends and opportunities. The articles have been grouped under ten different application areas which include (1) polymer solutions and phase behavior, (2) polymerizations, (3) particle formation/micronization/drug delivery systems, (4) films, (5) fibers, (6) membranes, (7) nanocomposites, (8) porous materials - foams/scaffolds, (9) organogels, and (10) lignocellulosic polymers. In each category, articles are discussed under specific polymer or polymer type to better highlight those polymers that are receiving the greater level of attention. In 2014, more polymers were explored for their foamability, and for generation of nanocomposites. Poly(epsilon-caprolactone), poly(lactic acid) and poly(lactide-co-glycolide) were the most frequently investigated polymers for their porous matrix formation, or particle formation features using supercritical carbon dioxide because of their biomedical significance as biodegradable platforms for tissue engineering scaffolds and drug delivery devices. Poly(ethylene oxide), poly(lactic acid), and poly(methyl methacrylate) were the polymers that were explored in multiple application areas. Based on the close examination of these publications, the review provides specific observations on the advances that are made toward improved understanding of the factors that affect the miscibility of polymers in carbon dioxide, and for further understanding of the synergistic or other effects of components in polymer blends and composites, including the consequences of the presence of crystalline versus amorphous domains and morphological differences, or the consequences of the presence of nanofillers in different applications. New perspectives that are emerging in each application area are presented. (C) 2015 Elsevier B.V. All rights reserved.