Accelerated aging of cellulose-based composites in different climate environments : A project provided by Biofiber Tech Sweden AB

Abstract: This paper reviews the effects of accelerated aging with increased humidity and temperature on cellulose-based composites. The composites consist of a matrix of plastic reinforced with cellulose fibers. The company Biofiber Tech Sweden AB provided four different composites and a conventional polyolefin as reference. The aim was to examine changes in mechanical properties, chemical composition and appearance after aging, as well as variations between materials. Two different climate conditions were tested, 85% RH and <10% RH, both in 90℃. A climate chamber and an oven were used to create the extreme environmental conditions. To analyze the results, tensile testing and FTIR were performed, and color intensity and density were measured. All samples decreased in color intensity throughout aging, and dark irregularities appeared on some of the samples exposed to high humidity, which may be due to fungal formation. The tensile testing showed a general difference between high and low RH and the toughness showed a tendency to decline with aging in high humidity for many samples. The FTIR measurements also did not show any general trend. To improve the study, it would be desirable to age the material for a longer time and at a higher temperature. Overall, more samples and measurements within each characterisation technique would be needed to achieve more reliable results. Nevertheless, this study hopes to be a starting point for further research on the long-term durability of Biofiber Tech’s composites.