Influence of external plasticization on rheological and thermal properties of cellulose acetate with respect to its foamability

Cellulose acetate needs appropriate plasticization for proper processing and achieving suitable properties. At thermoplastic foam production via melt technologies rheological and thermal properties are key factors for the generation of high quality products. Therefore, the influence of external plasticization on rheological and thermal properties of cellulose acetate (CA) was investigated. Different types of plasticizers were used for this study. The influence on the properties depends largely on the type of plasticizer and its compatibility with CA. Glass transition temperature of CA decreased significantly with increasing plasticizer content whereas thermal stability of CA remains almost constant. Melt processing is enhanced due to broadening of the thermoplastic window. The rheological behavior of CA was significantly improved by increasing plasticizer content. Melt flow increases while melt viscosity decreases with an increase in plasticizer content. Also melt strength and drawability were considerably improved. As expected, plasticizer performance is closely linked to the miscibility and mutual compatibility of the plasticizer with CA.