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Sound-absorbing green composites based on cellulose ultra-short/ultra-fine fibers

In this paper studies on sound absorption of the thermoplastic composites on the basis of waste natural fibers are presented. Cotton fibers and cellulose ultra-short and ultra-fine fibers obtained from flax fibers following enzymatic and additional mechanical treatment were used as the components of polylactide composites, and their influence on sound absorption behavior was investigated. The composites were obtained from a pressing process of fibrous multilayer structures. The sound absorption properties of three types of composites were compared: composites reinforced by cotton fibers, composites reinforced by cellulose ultra-short and ultra-fine fibers, and composites reinforced by cotton fibers and cellulose ultra-short and ultra-fine fibers. The role of cellulose ultra-short and ultra-fine fibers in changing the sound absorption properties of composites was determined. It has previously been shown that using natural fibers with a thermoplastic polymer results in increased sound absorption. The best improvement of sound absorption can be obtained by combining cotton fibers and cellulose ultra-short and ultra-fine fibers, especially nanofibers, as a reinforcement.