Accelerating the Biodegradation of Poly(lactic acid) through the Inclusion of Plant Fibers: A Review of Recent Advances

Abstract

As the global demand for plastics continues to grow, plastic waste is accumulating at an alarming rate with negative effects on the natural environment. The industrially compostable biopolymer poly(lactic acid) (PLA) is therefore being adopted for use in many applications, but the degradation of this material is slow under many end-of-life conditions. This Perspective explores the feasibility of accelerating the degradation of PLA through the formation of PLA-plant fiber composites. Topics include: (a) key properties of PLA, plant-based fibers, and biocomposites; (b) mechanisms of both hydrolytic degradation and biodegradation of PLA-fiber composites; (c) end-of-life degradation of PLA and PLA-plant fiber composites in aerobic and anaerobic conditions, relevant to compost, soil and seawater (aerobic), and landfills (anaerobic); and (d) sustainability and environmental impact of PLA and PLA-plant fiber composites, as evaluated using life cycle assessment. Additional degradation modes, including thermal and photodegradation, which are relevant during processing and use, have been omitted for clarity, as have other types of PLA biocomposites. Multiple studies have shown that the addition of some types of plant fibers to PLA (to form PLA biocomposites) accelerates both water transport in the material and hydrolysis, presenting a possible avenue for improving the end-of-life degradation of these materials. To facilitate the continued development of materials with enhanced biodegradability, we identify a need to implement testing protocols that can distinguish between different degradation mechanisms.

Development of Green Composite Utilizing Sisal Strands and Sustainable 3-D Printed PLA Layers

“…The cleaned PLA and sisal fibres are then reprocessed using techniques such as extrusion or injection moulding to create new composite products. Several studies have investigated the long-term degradation behaviour of PLA/sisal composites to understand their performance over time in various environmental conditions [47,53,54].…”

Designed to Degrade: Tailoring Polyesters for Circularity

“…Ideally, these additives do not change the material properties and processability of the product, while they can effectively initiate and ensure the degradation of the material after service. The possibility to accelerate the biodegradation of polyesters by inclusion of plant fibers was recently reviewed and will not be further discussed here . Instead, we will briefly discuss chemical or biological catalysts as additives that can accelerate the hydrolytic degradation rate when the material comes in contact with aqueous environments, soil, or compost.…”

Fast Sweat Wicking Enabled by Unidirectional Water Transport in Biodegradable Trilayered Porous Membranes Produced via Papermaking

“…Currently, environmental issues are increasingly severe . The moisture wicking materials available on the market are predominantly composed of synthetic fibers that are nondegradable or have a lengthy degradation cycle. − To combat this form of “white pollution”, the implementation of biodegradable materials proves to be an effective solution. − PLA, a biodegradable biopolymer, has been extensively used in the market due to its high strength, biocompatibility, and simplicity in processing, which makes it a viable substitute to petrochemical-derived products because of its production through microbial fermentation of agricultural byproducts, including carbohydrate-rich substances such as corn, sugar beets, and sugar cane. , The composting of pure PLA material is necessary for its degradation, and multiple studies have shown that the addition of some types of plant fibers to PLA (to form PLA biocomposites) accelerates both water transport in the material and hydrolysis. , Plant fiber, one of the most plentiful natural renewable biological resources, which is composed of cellulose mainly, is widely sourced and extensively procured owing to its completely degradable advantages. − Hydroxyl groups on the surface of cellulose are the prevalent functional groups, giving the plant fibers hydrophilic nature . And intermolecular hydrogen bonding endows the plant fibers with better mechanical strength.…”