Preparation And Properties Of Sound Absorption And Insulation Composites Based On Waste Polyphenylene Sulfide Filter Materials

With the development of modern industry and information technology,noise pollution is becoming more and more prominent.Together with air pollution,water pollution and solid waste pollution,it is listed as the four major pollution in the world.Therefore,the demand for sound-absorbing materials is growing day by day,and new sound-absorbing materials with excellent performance have also received more and more attention.Based on polyphenylene sulfide(PPS)fibers with excellent mechanical properties,high temperature resistance,chemical stability,flame retardancy and good machinability,this paper uses alkali washing process to dispose of the waste PPS filter material.After treatment,the treated PPS filter material is made of three kinds of sound absorbing and insulation composite materials,namely,single PPS filter material,PPS filter material and polyurethane(PU)film,PPS filter material and PU foam.The microstructure,mechanical properties and sound absorption and insulation properties of the three types of materials are tested and analyzed respectively,and the effects of different materials and structures on the sound absorption and insulation properties of the composites are studied.The main conclusions are as follows:After alkaline washing,most of the dust cake on the surface of the waste PPS filter material can be removed,but there are still a small amount of dust particles,and the fiber integrity is high,without obvious fracture and damage;The mechanical properties of waste PPS filter material decreased,the zonal breaking strength and meridional breaking strength decreased by 19.5% and 1.9% respectively compared with the unused PPS filter material,and the overall tensile properties remained good;The toughness and brittleness of the waste PPS filter material after alkali washing decreased,and the bursting strength decreased by 28.6%compared with the unused PPS filter material;During the use of PPS filter material in high temperature environment,oxidation reaction occurs,resulting in the fracture and crosslinking of PPS macromolecular chain,and a part of small molecular substances are generated,which reduces the crystallinity and thermal stability of the filter material.The warp and weft breaking strength and elongation at break of the composite composed of single waste PPS filter material are positively correlated with the number of layers;The sound absorption coefficient increases at first and then decreases at high frequency;At 6300 Hz,the sound absorption coefficient of three-layer sound-absorbing composites can reach 0.55.The sound insulation performance of multi-layer composites is positively correlated with the number of layers.At 6300 Hz,the sound transmission loss of five-layer sound-absorbing composites can reach 32 dB.Four kinds of sound absorption and sound insulation composites with sandwich structure were prepared by compounding waste PPS filter material and PU membrane.It is found that the mechanical properties of composites with the same structure are positively correlated with the thickness of single-layer PU film;The sound absorption coefficients of the four sandwich structure composites show the same change trend,and the sound absorption coefficient is negatively correlated with the single-layer film thickness,up to 0.27 in the high-frequency stage;The transmission loss of the four composites also showed the same trend,but the transmission loss was positively correlated with the single-layer film thickness,and the highest transmission loss in high frequency stage was41 d B.Four kinds of sound absorbing and sound insulation composite materials with the same structure of PU film were prepared by compounding the waste PPS filter and PU foam.It is found that the four composites have excellent sound absorption properties,and the average sound absorption coefficient of the four composites is more than 0.8,up to 0.98;The sound absorption properties of the four kinds of composite materials are positively correlated with the thickness of the single layer foam.However,the sound insulation performance of the four composites is poor,and the transmission loss is less than 27.5 dB.