Research Of Polypropylene Sound Insulating Materials

Polypropylene is excellent in properties of mechanical and thermal properties and weather resistance. This thesis contains3methods to modify PP to improve the property of noise reduction based on the attainment of related national standards:foaming, the use of inorganic filler BaSO4and talcum powder and the blend with isobutylene isoprene rubber (IIR), after the analysis of the mechanism of PP to diminish noise, which is combined with the current study of such property domestic and overseas.The mechanical property was tested using universal testing machine; the thermal property was analyzed using differential scanning calorimetric (DSC), and vicat softening temperature and linear coefficient thermal expansion; the fracture surface micro structure were observed using high-power microscope and SEM respectively; the noise reduction efficiency was characterized using the method of density, DMA and stationary wave pipe.The results showed that the mean noise reduction value for PP was18.6db; When the content of Talc was30%the system attained the noise reduction25.5db, increased37.1%compared to pure PP; with the increase of IIR in PP/IIR blend system, the strength decreased, but the noise reduction increased, which is21.0db when the content of IIR is10%, increased12.9%compared to pure PP and the stretching and bending strengths of which were18.8MPa and23.7MPa respectively, so the comprehensive property of the material is the best; The system was highest in porosity when the content of AC is2%, where the foamed PP reached the highest noise reduction21.3db, increased14.5%compared to mean noise reduction value of the pure PP,the stretching and bending properties are13.6and30.5MPa respectively and the vicat softening temperature was62.4℃; For the modified material BaSO4/PP, when the content of BaSO4was40%the system attained the largest noise reduction32.1db, increased12.9%compared to pure PP,where the stretching and bending strengths were19.6MPa and31.0MPa respectively, the vicat softening temperature was74.3℃and linear coefficient of thermal expansion was0.84×10-4/℃, which were superior compared to PP.