Hemp hurd filled PLA‐PBAT blend biocomposites compatible with additive manufacturing processes: Fabrication, rheology, and material property investigations

Abstract

A co‐continuous 50:50 blend of poly(lactic acid) (PLA) and poly(butylene adipate‐co‐terephthalate) (PBAT) was compounded with 10–40 wt% hemp hurd microparticles (<250 μm) to achieve balanced material properties for additive manufacturing (3D printing) applications. The blend and composites were further compatibilized with maleic anhydride via an in situ reactive extrusion process to enhance the adhesion between the polymers and the fillers and subsequently improve stress transfer between the components. All composite samples were processed further via injection molding and 3D printing processes to analyze and compare the rheology, morphology, thermal, mechanical properties, and other physio‐chemical properties. For the unfilled polymer blends, the injection molded and 3D printed sample specimens displayed similar mechanical properties. However, in the hemp filled composites, the injection molded specimens demonstrated enhanced mechanical properties. This indicates that the 3D printing process requires further parameter optimization to eliminate potential gaps between the printing layers and enhance mechanical properties. Overall, the PLA:PBAT blends filled with hemp hurd microparticles provided balanced composite properties in addition to their sustainability attribute, which makes them an appealing alternative for the fabrication of compostable and tough materials via additive manufacturing processes.Highlights Upon maleation, the blend components formed a co‐continuous morphology. Sustainable plastic filament with up to 40 wt% hemp hurd micro particles. 3D printing can compete with injection molding in filled composites. Successfully 3D printed model furniture with 30 wt% hemp filler.

A review on polylactic acid‐based blends/composites and the role of compatibilizers in biomedical engineering applications

“…The role of plasticizers/compatibilizers on the melt elasticity, viscosity, processability and mechanical behavior of PLA/PBAT has been extensively investigated. Example: Maleic anhydride, benzoyl peroxide, nanohydroxyapatite, nanoclays, cloisite 93A, cloisite 30B (C30B), organoclay (OC), chitosan, Bioflex F2110, epoxy‐functionalized oligomer Joncryl ADR@‐4368 (ADR), poly(hydroxybutylate‐co‐valerate) (PHBV), poly(butylene succinate) (PBS) 106,110‐116 . Similarly, adding nano‐HA particles in a ratio <6 wt% enhance the crystallinity of PLA by 62%.…”

Development of biodegradable filaments based on agro‐industrial waste and evaluation of process parameters in final properties

“…by Jubinville et al 11 Some adaptations were carried out to adjust these parameters, as the addition of fillers tends to profoundly alter the deposition behavior of the material due to the specific characteristics, such as patterns and orientations suitable for the construction of the part. In this way, some parameters were adjusted, such as 100% filling and different orientations to identify the complete mechanical characteristic of the developed compositions.…”

“…X-ray fluorescence of agroindustrial residues X-ray fluorescence was used for chemical analysis of agro-industrial residues. X ray fluorescence(XRF) was performed using Shimadzu EDX-720 equipment with a detection limit of Na (11) to U (92) (>0.1%). Firstly, the samples were dried in an oven at 110 C for 24 h and subsequently heated at 1000 C for 60 min to in order to determine loss on ignition (LOI).…”

“…The processing of polymer composites by additive manufacturing is still a challenge, as processing conditions must be taken into account and controlled, as well as rheological and flow changes during the forming of the part. [10][11][12] According to Park and Fu, 13 the essential parameters for processing polymers into 3D filaments include layer thickness, melting temperature, printing table temperature, deposition speed, part filling pattern, internal configuration of the part, raster width, raster angle, and spacing between rasters. Among these factors, the raster angle, which determines the part deposition direction, has a significant impact on many of the main characteristics that influence the final quality and cost of the prototype.…”

“…16 Developing new filaments by incorporating agro-industrial waste into biodegradable polymers brings sustainable approaches to waste management and the development of biocomposites in association with polymer processing technologies. 11,17 Examples of agro-industrial residues available at low cost are soybean and peanut shells, rich in cellulose and hemicellulose, which can act as a reinforcing filler in polymer composites but which are rarely reported in the literature for application in additive manufacturing. 18 Therefore, the objective of this research was to evaluate the effect of incorporating agro-industrial lignocellulosic waste of peanut and soybean shells into a biodegradable polymer matrix of polybutylene adipate terephthalate (PBAT) for the purpose of filament production at different raster angles while concurrently examining its influence on printability and mechanical properties across.…”