Non-isothermal cold crystallization kinetics of cork–polymer biocomposites based on polylactic acid for fused filament fabrication

• Published in: Journal of thermal analysis and calorimetry 2021-11, Vol.146 (4), p.1667-1678
• Main Authors: Magalhães da Silva, S. P., Silva, Mónica A., Oliveira, José M.
• Format: Article
• Language: English
• Subjects: Analysis; Analytical Chemistry; Biomedical materials; Biopolymers; Calorimetry; Chemistry; Chemistry and Materials Science; Cold; Cold crystallization; Crystallization; Crystals; Filaments; Fused deposition modeling; Inorganic Chemistry; Measurement Science and Instrumentation; Optical microscopy; Physical Chemistry; Polylactic acid; Polymer industry; Polymer matrix composites; Polymer Sciences; Polymers; Powders; Structure
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-020-10147-6

Cork–polymer composites (CPC) based on polylactic acid (PLA) matrix were prepared for the development of filaments for fused filament fabrication. The non-isothermal cold crystallization behaviours of PLA and CPC were investigated by differential scanning calorimetry. Cold crystallization kinetic behaviours of PLA and CPC with 15 mass/% of cork powder residues at different heating rates (1.25, 2.5, 5 and 7.5 K min −1 ) were studied. Results showed that cold crystallization temperature ( T cc ) of PLA matrix decreased with the addition of cork. Crystallization kinetic behaviour was studied by Avrami and Tobin models. It was shown that cork powder surface acts as a nucleating agent during non-isothermal cold crystallization, by accelerating the crystallization rate and, therefore, by reducing the half-time crystallization ( t 1/2 ) values. Polarized optical microscopy and X-ray diffraction were used to evaluate the crystalline structure of PLA and CPC. Kissinger and Friedman methods were employed to determine the crystallization activation energy ( E c ).