Thermal and rheological properties of self-fabricated polyethylene glycol-plasticized poly(lactic acid) filaments for fused deposition modeling

Abstract

In this work, thermal and rheological properties of self-fabricated polylactic acid (PLA) filaments without and with 10-wt% polyethylene glycol (PLA/0PEG and PLA/10PEG, respectively) were investigated, and the properties were compared with a commercial PLA filament used for fused deposition modeling (FDM). The result showed that the melt flow index for self-fabricated filaments was comparable with commercial filaments at approximately 10 g/10 min at 190°C, suggesting suitability to be used as filament for FDM with well-wetted layers. Variation in thermal properties was found in PLA/10PEG with 20°C higher cold crystallization temperature (T _cc) after FDM in which disruption of the molecular arrangement reduced the ability for chain alignment and folding. The result also revealed that addition of PEG decreased the storage modulus (G′), loss modulus (G″), and complex viscosity (η*), resulting in slow crystallization behavior, and however, the properties did not induce degradation of the filaments and printing products.