Development of bio-based expanded cork polymer composites (eCPC) with poly(lactic acid) (PLA)

Abstract

Expanded cork polymer composites (eCPC) using a PLA matrix and expandable microspheres (EMS) were developed and characterized. A blowing agent was introduced to evaluate its effect on cork structure in eCPC injected pieces. A chemical and thermal characterization was conducted using Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared-Attenuated Total Reflection (FTIR-ATR) to investigate the effect of cork and EMS in eCPC. The results have shown that the introduction of cork and EMS led to composites with up to 8% less density and with lower temperature of cold crystallization. The presence of cork in CPC and eCPC allowed to lower the cold crystallization temperature by almost 13 ºC. It was found an increase on the crystallinity degree in the presence of cork and EMS. Scanning Electron Microscopy (SEM) was used to perform morphological studies. A recovered alveolar structure was found for cork cells in eCPC injected pieces.