In vitro degradation analysis and mechanical characterization of PLA-CF composites prepared by fused filament fabrication technique for bio-medical applications

Abstract

The objective of this research work is to study the in vitro degradation behavior of as-fabricated and annealed Poly Lactic Acid (PLA) composites reinforced with varying volume fractions of carbon fiber (CF).The composites are prepared by fused filament fabrication technique (FFF). Specimens are immersed in simulated body fluid (SBF) for 8 weeks to study the degradation behavior of the composites by examining the change in weight, change in pH and degradation in mechanical properties. The obtained results show that the addition of carbon fiber reinforcement reduces the tensile strength, flexural strength, impact strength and compressive strength of the composites. Further, CF addition enhances the tensile modulus of the composite. The mechanical properties of annealed composites are enhanced when compared to as-fabricated composites. Differential Scanning Calorimeter (DSC) is employed to study the thermal characteristics of the composites and % crystallinity of the composites. CF addition reduces the crystallinity of the composites. Fractographs of the tensile fractured specimens are studied using a scanning electron microscope (SEM). The addition of the carbon fiber reinforcement is found to accelerate the degradation behavior of the composites. There is significant change in weight and pH as well as degradation in mechanical properties of PLA-CF composites immersed in SBF than pure PLA composites. Annealed composites show better degradation resistance than as-fabricated composites. SEM is employed to study the surface morphology of the composites immersed in SBF.