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

Sina Momeni; Muhammad Safder; Mohammad Abu Hasan Khondoker; Anastasia Leila Elias

doi:10.3390/polym13213786

Polymers (Nov 2021)

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

Sina Momeni,
Muhammad Safder,
Mohammad Abu Hasan Khondoker,
Anastasia Leila Elias

Affiliations

Sina Momeni: Donadeo Innovation Centre for Engineering, Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
Muhammad Safder: Donadeo Innovation Centre for Engineering, Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
Mohammad Abu Hasan Khondoker: Donadeo Innovation Centre for Engineering, Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
Anastasia Leila Elias: Donadeo Innovation Centre for Engineering, Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada

DOI: https://doi.org/10.3390/polym13213786
Journal volume & issue: Vol. 13, no. 21
p. 3786

Abstract

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Sourced from agricultural waste, hemp hurds are a low-cost renewable material with high stiffness; however, despite their potential to be used as low-cost filler in natural fiber reinforced polymer biocomposites, they are often discarded. In this study, the potential to add value to hemp hurds by incorporating them into poly(lactic acid) (PLA) biopolymer to form bio-based materials for packaging applications is investigated. However, as with many plant fibers, the inherent hydrophilicity of hemp hurds leads to inferior filler-matrix interfacial interactions, compromising the mechanical properties of the resulting biocomposites. In this study, two chemical treatments, alkaline (NaOH) and alkaline/peroxide (NaOH/H2O2) were employed to treat hemp hurds to improve their miscibility with poly(lactic acid) (PLA) for the formation of biocomposites. The effects of reinforcement content (5, 10, and 15 wt. %), chemical treatments (purely alkaline vs. alkaline/peroxide) and treatment cycles (1 and 3 cycles) on the mechanical and thermal properties of the biocomposites were investigated. The biocomposites of treated hemp hurd powder exhibited enhanced thermal stability in the temperature range commonly used to process PLA (130–180 °C). The biocomposites containing 15 wt. % hemp hurd powder prepared using a single-cycle alkaline/peroxide treatment (PLA/15APHH1) exhibited a Young’s modulus of 2674 MPa, which is 70% higher than that of neat PLA and 9.3% higher than that of biocomposites comprised of PLA containing the same wt. % of untreated hemp hurd powder (PLA/15UHH). Furthermore, the tensile strength of the PLA/15APHH1 biocomposite was found to be 62.6 MPa, which was 6.5% lower than that of neat PLA and 23% higher than that of the PLA/15UHH sample. The results suggest that the fabricated PLA/hemp hurd powder biocomposites have great potential to be utilized in green and sustainable packaging applications.

Published in Polymers

ISSN: 2073-4360 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Chemistry: Organic chemistry
Website: http://www.mdpi.com/journal/polymers/

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