Study on sound absorption property of ramie fiber reinforced poly( l-lactic acid) composites: Morphology and properties

The effect of ramie fiber, flame retardant and plasticizer on sound absorption property of ramie fiber reinforced PLLA composites was investigated. We used press molding process to prepare the ramie fiber/PLLA composites, with short ramie fiber and ramie plain weave fabric as the reinforcement. The dispersivity of flame retardant ammonium polyphosphate (APP) was indirectly tested by thermogravimetric analysis (TGA). The result of sound absorption property measurement shows that the composites with short ramie fiber have better sound absorption property than the ramie fabric reinforced PLLA composites. And the addition of APP and plasticizer poly(butylene adipate-co-terephthalate) (PBAT) improves the sound absorption property of ramie fabric/PLLA composites. Moreover, morphological studies by scanning electron microscopy (SEM) demonstrate the micro-phase separation in the PBAT/PLLA composites and the porosity of the single ramie fiber bundle. The results suggest that these special structures are the main reason for the better sound absorption property.