Effect of egg white protein and water content on the stabilization mechanisms of natural rubber latex foams obtained from microwave radiation

Abstract

The global plastic consumption, as one of the paramount concerns of our society, opens new paths of investigation in green materials. This study presents contribution to the field with the obtention of natural rubber latex foams (NRLF using egg white powder (EW) as the biostabilizing agent. The route followed to develop these samples is based on a two-step process, a previous aeration, followed by microwave dehydration. This synthesis route is greener and ecofriendlier than conventional ones due to the use of bio-based bulk materials, the utilization of microwave radiation which reduces the energy consumption in comparison with conventional heating methods, and the elimination of the vulcanization process typically used when producing latex foams. Herein, a deep study of the effect of EW on NRLF obtained at three water content levels (i.e., 40, 70, 90 phr) is carried out. The density and cellular structure parameters are measured for the formulations of liquid and solid foams to comprehend the stabilization mechanisms due to the presence of the EW and the effect of water content. It has been possible to produce open-cell natural rubber latex foams with densities as low as 53 kg m−3 and cell sizes as low as 114 μm.