Expanding Poly(lactic acid) (PLA) and Polyhydroxyalkanoates (PHAs) Applications: A Review on Modifications and Effects

Abstract

The high price of petroleum, overconsumption of plastic products, recent climate change regulations, the lack of landfill spaces in addition to the ever-growing population are considered the driving forces for introducing sustainable biodegradable solutions for greener environment. Due to the harmful impact of petroleum waste plastics on human health, environment and ecosystems, societies have been moving towards the adoption of biodegradable natural based polymers whose conversion and consumption are environmentally friendly. Therefore, biodegradable biobased polymers such as poly(lactic acid) (PLA) and polyhydroxyalkanoates (PHAs) have gained a significant amount of attention in recent years. Nonetheless, some of the vital limitations to the broader use of these biopolymers are that they are less flexible and have less impact resistance when compared to petroleum-based plastics (e.g., polypropylene (PP), high-density polyethylene (HDPE) and polystyrene (PS)). Recent advances have shown that with appropriate modification methods—plasticizers and fillers, polymer blends and nanocomposites, such limitations of both polymers can be overcome. This work is meant to widen the applicability of both polymers by reviewing the available materials on these methods and their impacts with a focus on the mechanical properties. This literature investigation leads to the conclusion that both PLA and PHAs show strong candidacy in expanding their utilizations to potentially substitute petroleum-based plastics in various applications, including but not limited to, food, active packaging, surgical implants, dental, drug delivery, biomedical as well as antistatic and flame retardants applications.

Carbon Fiber/PLA Recycled Composite

“…Therefore, researchers are encouraged to work on environmental solutions to the problem of collecting and increasing waste of polymeric materials to protect the earth’s natural resources and to develop a sustainable society. Several suggestions have arisen in response to studies by researchers including curbing the use of plastics, applying bio-degradable plastic materials, shifting towards non-plastic materials, etc., according to the needs of the society [ 2 ]. Proposals for a sudden shift to remove plastics from the world, however, is criticized by many sectors, including products and services, because a drastic shift may cause economic instability in the world due to the linkage of a wide variety of economic and social strings with the plastic industry [ 3 ].…”

4D structures for the short-time building of emergency shelters

“…PLA being a biodegradable material may have some durability issues to overcome, particularly for more long-term applications. 69–78 However, the final proposed solution used SMP, which still deserves attention to durability issues, but at a different scale. 79–80…”

Physicochemical Characterization and Finite Element Analysis-Assisted Mechanical Behavior of Polylactic Acid-Montmorillonite 3D Printed Nanocomposites

“…In this paper, the term “MMT” is used to represent the Cloisite ® 20A, and the term “PLA” will be used to simplify and represent the term “PLA/Joncryl”. The chemical structures of PLA, Joncryl, and MMT are shown in Figure 1 a–c [ 31 , 32 ].…”