Melt compounding of poly (Lactic Acid) and talc: assessment of material behavior during processing and resulting crystallization

The influence of talc incorporation by melt compounding on a commercial grade of poly (lactic acid) (PLA), and the choice of the optimal compounding conditions were investigated. Two types of talc, having micrometric and submicrometric distribution, were adopted. Since the compounding itself has a dramatic influence on the properties of PLA, a study was carried out aimed at assessing the effect of processing on this resin and choosing the most suitable processing conditions. It was found that the incorporation of talc increases the viscosity during the compounding and helps the stability of the viscosity during the mixing. Furthermore, the talc, acting as a nucleating agent, enhances crystallization kinetics, so that crystallization half time can be reduced by one order of magnitude with respect to the pure PLA processed in the same way.