Melting and crystallization of PHB/ZnO compounds

Abstract

Compounds of poly(3-hydroxybutyrate) (PHB) and zinc oxide with filler content between 1 and 10% were prepared in a laboratory internal mixer. The effect of heating and cooling rates on the crystallization and melting of PHB/ZnO compounds was investigated by differential scanning calorimetry. Physical aspects of the compounds were examined by means of scanning electron microscopy and optical microscopy. Melt and cold crystallization rates rise with increasing cooling/heating rates. The melt crystallization temperatures and maximum melt crystallization rates are almost unaffected by the filler, independent on the filler concentration. The main effect of ZnO on PHB is to reduce the overall crystallinity obtained after a successive melt and cold crystallization events. For defined filler content, Mo model can be applied for the description of tested and untested heating/cooling rates, provided that a lower accuracy is acceptable.