Valorization of Hemp Hurds as Bio-Sourced Additives in PLA-Based Biocomposites

Area of Science:

• Materials Science
• Polymer Science
• Biocomposites

Background:

• Hemp hurds, an agricultural waste, are a low-cost, stiff, renewable resource.
• Their hydrophilicity hinders integration into poly(lactic acid) (PLA) biopolymers, limiting biocomposite applications.
• Value addition to hemp hurds can be achieved by developing novel bio-based packaging materials.

Purpose of the Study:

• To investigate the value addition of hemp hurds as filler in PLA biocomposites for packaging.
• To improve hemp hurd miscibility with PLA through chemical treatments.
• To evaluate the impact of reinforcement content, chemical treatments, and cycles on biocomposite properties.

Main Methods:

• Hemp hurds were chemically treated using alkaline (NaOH) and alkaline/peroxide (NaOH/H2O2) methods.
• Biocomposites were fabricated with varying hemp hurd content (5, 10, 15 wt. %).
• Mechanical and thermal properties of the resulting biocomposites were analyzed.

Main Results:

• Treated hemp hurd powder improved the thermal stability of PLA biocomposites within processing temperatures (130-180 °C).
• Biocomposites with 15 wt. % treated hemp hurds (PLA/15APHH1) showed a 70% increase in Young's modulus compared to neat PLA.
• The tensile strength of PLA/15APHH1 was 23% higher than biocomposites with untreated hemp hurds (PLA/15UHH).

Conclusions:

• Chemical treatment significantly enhances the interfacial interaction between hemp hurds and PLA.
• The developed PLA/hemp hurd powder biocomposites demonstrate promising mechanical and thermal properties.
• These biocomposites hold significant potential for use in green and sustainable packaging solutions.