Novel porous fiber-based composites with excellent sound-absorbing and flame-retardant properties

Novel ultralight porous fiber-based composites are a very attractive subject in the material chemistry and are enabled to promise applications in the sound absorption fields. In this work, it reported a facile strategy to prepare the flame-retardant, sound-absorbing, and mechanical enhancement porous fiber-based composites (PFC-EM-x) by using natural cellulose fiber, glass fiber, and flame retardant. Subsequently, the expandable microspheres (EMs) were added to construct the well-defined porous microstructure of materials for the enhancement in sound-absorbing performance. The results demonstrated that the high EMs contents had a remarkable influence on the porous structure of the composites so that the composites achieved the outstanding sound-absorbing performance and acceptable mechanical properties compared with other reported materials, especially as-prepared PFC-EM-20 composite showed excellent sound absorption at a range of high frequencies with the maximum sound absorption coefficient of 0.781 and tensile strength of 1.07 kN/m. Moreover, the limiting oxygen index values of all the samples were more than 26, both V1 and V2 rating in UL-94 test were achieved, which indicated that the obtained PFC-EM-x composites displayed outstanding flame retardancy. In summary, this study provides a facile strategy to rationally construct mechanically robust, highly efficient sound-absorbing and flame retardant ultralight composites which have promising applications in the future as green engineering materials.