Abstract:
This study focuses on preparing pure polylactic acid (PLA) and polybutylene adipate –co-terephthalate (PBAT)-reinforced PLA filaments. PLA and PBAT are biodegradable aliphatic polyesters and have recently received considerable attentions. Due to its brittle nature, PLA has limited application in various fields. To overcome this challenge, numerous efforts have been made to incorporate various additives to enhance its performance. In this work, pure PLA filament and PBAT-reinforced PLA filament with diameter 1.75 ± 0.02 mm were prepared in the lab. Their thermal and mechanical properties were analyzed and compared with the commercial PLA filament bought from the market. Following the previous research works and suggestions of incorporating no more than 10 wt.% PBAT, we have mixed 8 wt.% PBAT into the PLA mixture. We then proceeded to extrude pure PLA and PBAT-reinforced PLA filaments at a temperature range of 170 oC to 180 oC, utilizing single screw extruder. Next, we printed tensile and flexural specimens using an FDM 3D printer, in accordance with Taguchi L9 OA. Due to PBAT’s high ductility, 92-8 wt.% PLA-PBAT filament demonstrated a significant increase in elongation at break, reaching up to 12%. Likewise, the PLA-PBAT filament displayed tensile and flexural strengths of up to 48.34 MPa and 107.295 MPa respectively. These values are comparable to the tensile and flexural strengths of pure PLA, which is a great indication that the addition of 8 wt.% PBAT did not cause any unacceptable reduction in the tensile and flexural strengths. Additionally, it was found through DSC analysis that PLA-PBAT filament exhibited a higher degree of crystallinity (Xc) of up to 38.7%, which is significantly higher than that of pure extruded PLA. Furthermore, the TGA curve indicated that thermal stability of PLA-PBAT filament was improved by adding 8 wt.% PBAT. Moreover, digital microscopy results revealed that PLA-PBAT filament had a ductile fracture after necking, whereas pure PLA had a brittle fracture. Lastly, statistical analysis showed that both material type and layer thickness had significant impact on the results. The addition of this new PLA-PBAT filament provides an additional alternative to the current FDM filaments, and it will aid in reducing the constraints of the materials when it comes to additive manufacturing (AM) progress.
