The New Light Composite Material For Sound Insulation Based On Waste Recycling And Photonic Crystal

Thin sound insulation composites and phononic crystal have been a researchhotspot in the field of environmental noise reduction, particularly the research ofbroadband sound insulation composites has become a new trend in the developmentof noise reduction functional ecomaterials, which has great significance for improvingthe plot ratio and reducing the load-bearing of high-rise buildings. Exploring tomodify polyurethane foam with waste slag, and construct a two-dimensional photoniccrystal structure with tubes array in which, not only can achieve hybrid compositewith broadband sound absorption and insulation property，which realizes integrationof composites’ noise reduction performance and photonic crystal’s local band gapeffect, but also realized the waste slag resource utilization, it will be valuable inapplication.Based on solid waste resource recovery and phonon crystal theory, a light andthin polyurethane (PU) composite both with broadband acoustic absorption andinsulation properties was designed and prepared in this research. Its acousticinsulation was improved by the method that mixing waste slag (WS) in PU matrix andstrengthened the meridian of PU matrix，meanwhile，the acoustic insulation domainwas broaden by setting a two-dimensional array structure skeleton. First, orthogonalexperimental method was used to study the technology and process parameters ofgangue slag (GS), copper tailing slag (CS) and limestone slag (LS)，three kinds of WSmodified PU composite materials. The process parameters of three kind soundinsulation optimal WS/PU composites and three kind sound absorption optimal weredetermined, and be verified. Next, with PU materials as matrix, constructing twodimensional periodic tubes array structure (PC) in which during the foaming process,a PC/PU acoustic absorbing and insulation composite material was prepared, and theimpact factors of the sound absorption and insulation properties of which such astubes array structure, tube’s diameter, material, and tubes array combination modewere discussed and reseached. Finally, according to optimal process parametersdetermined in two parts of former, the PC/WS/PU composite sound absorbing andinsulation composite material was gained, then which was made as the core layer toprepare multi-layer composite acoustic insulation panels trough aminating some frontpanels and damping layer, the combined action of component modifying and structuremodifying also be verified. The main conclusions are as follows：(1) PU foamed material could not only retain its remarkable sound absorptionproperty，but also improve acoustic insulation，trough mixing WS particles orformating PC internal structure during the foaming process. The combination of themcould also broaden the insulation frequency domain.(2) The sound insulation optimal technological condition of GS/PU composite isthat ratio of component A, B is2:8, foaming temperature is50℃, particle size is80mesh, particles addition volume is20%of the total dosage of A and B components (abbreviated as:2:8,50℃,80mesh,20%, similarly hereinafter the same below),CS/PU is4:6,50℃,60mesh,100%, LS/PU is5:5,70℃,120mesh,20%. The soundabsorption optimal technological condition of GS/PU composite is4:6,60℃,100mesh,100%, CS/PU is2:8,60℃,120mesh,100%; LS/PU is4:6,60℃,60mesh,20%. One of them，LS/PU sound absorption best specimen’s absorption propertiescan reach0.32, and the average acoustic transmission loss also reaching28dB (A).(3)The sound insulation performance and absorption properties of the PC/PUcomposites are significantly influenced by tubes array structure, tube’s diameter,material, and tubes array combination mode and so on. Considered cost andperformance， the most dominant PC/PU composite material is that adding stainlesssteel pipe and tube pore channel composite rectangular array structure compositematerial，of which diameter is4mm, the average sound insulation performance is34.2dB (A),compared to blank PU material， improving12dB (A), especially it alsoholds0.25average sound absorption performance.(4) The sound insulation performance of PU absorption material can beeffectively improved without adding any substance, only formating a periodic tubularpores channel array structure in its matrix.(5) A40mm thickness PC/LS/PU composite as the core leyel, laminatingcommon front-panels can achieve the third grade sound insulation criteria (≥40dB(A)) of dwelling of code for design of sound insulation of civil buildings(GBJ118-88). Meanwhile, when introducing thin damping layers, the average soundtransmission loss can be up to46.3dB (A), meet the above second grade criteria (≥45(dB (A)), particularly, the thickness is limited to less than50mm, to achieve a thinand light design goals.