Natural aging behavior and lifetime prediction of rubber latex foam with various natural-to-synthetic ratios

Abstract

Rubber latex foam (RLF) is a low-density, three-dimensional porous material that is susceptible to aging factors such as oxygen, heat, and light, leading to a loss of its excellent performance. This study conducted natural aging tests of the RLF with various proportions. The experimental conditions were divided into two categories: with and without fabric covering to better simulate the actual usage conditions. Subsequently, the performance of the RLF were conducted before and after aging, investigating the natural aging patterns of the RLF, and the influence of fabric covering conditions on aging. The results indicated that RLF with low N/R ratios has better aging resistance, and during natural aging, the N/R ratio did not show a significant relationship with the aging rate of the samples. From a microscopic perspective, samples covered with fabric maintain a more intact porous structure compared to those without fabric covering. In the process of thermo-oxidative aging, all samples underwent oxidation reactions. Finally, using the yellowness index as an evaluation criterion, the storage life of RLF was predicted by the variable activation energy method, and the quality and safety in actual production were further determined.