Advances in lubricated polydimethylsiloxane surfaces for polyurethane foam molding

Abstract

Adhesion problems are currently a challenge in the manufacture of molded polyurethane (PUR) foam products. Here, a novel solution has been proposed by infusing a polydimethylsiloxane (PDMS) matrix with a liquid lubricant to obtain slippery liquid-infused porous surfaces (SLIPS). These surfaces have been evaluated when PUR foam is molded on them. The level of adhesion, determined by tensile peel tests, helped to understand the relationship between adhesion phenomena, coating deformability and hysteresis contact angle. A wide variability of hydrophobicity and hardness was obtained among the tested samples. The percentage of oil infused and the way it is integrated into the coating matrix determine the coating performance. The adhesion strength has been significantly reduced thanks, on the one hand, to the lubricating layer generated from the infiltrated oil and, on the other hand, to a porous system capable of self-healing the altered SLIPS surface after demolding. An optimal balance between the elasticity and hydrophobicity of the surface has been obtained; the best surfaces with the least adherence and the greatest durability have been identified for obtaining the foam.