Biopolymers Research
Open Access

Polylactic acid (PLA); Renewable polymers; Bioplastics; Sustainable packaging; Biodegradability; Polymer characterization; Green materials

Introduction

Plastic pollution has become one of the most pressing environmental issues of the 21st century, largely due to the extensive use of petroleum-based polymers in single-use applications such as packaging. Traditional plastics are non-biodegradable, persist in the environment for hundreds of years, and contribute to significant ecological and health problems. In response to these challenges, there has been a growing interest in developing sustainable, bio-based alternatives that reduce environmental impact without compromising material performance [1]. Polylactic acid (PLA) is a leading candidate among renewable polymers due to its origin from natural resources like corn starch, sugarcane, or other carbohydrate-rich crops. As a biodegradable thermoplastic polyester, PLA offers several advantages, including good mechanical strength, processability, and biocompatibility. These characteristics make it particularly suitable for packaging applications, where sustainability and safety are paramount [2]. Despite its potential, PLA does have certain limitations, such as brittleness, relatively low thermal resistance, and slow degradation under ambient conditions. To address these issues, researchers have explored various modification strategies including copolymerization, blending with plasticizers, and reinforcement with natural fibers or nanoparticles. This study aims to develop and characterize PLA-based renewable polymer composites for use in sustainable packaging [3]. Through thermal, mechanical, and morphological analyses, the research evaluates the performance of modified PLA materials to determine their suitability as environmentally friendly packaging solutions. The ultimate goal is to contribute to the development of biodegradable materials that align with circular economy principles and help reduce reliance on fossil-fuel-derived plastics.

Discussion

The results from this study highlight both the potential and the challenges of using polylactic acid (PLA)-based renewable polymers in sustainable packaging applications. Initial mechanical testing of pure PLA confirmed its high tensile strength and stiffness, which are beneficial for rigid packaging formats. However, its inherent brittleness and relatively low elongation at break limit its performance in applications requiring flexibility or impact resistance [4,5]. To overcome these limitations, plasticizers such as polyethylene glycol (PEG) and citrate-based additives were incorporated into the PLA matrix. These additives effectively increased the polymer's flexibility, as evidenced by improved elongation values in tensile testing. However, a trade-off was observed in tensile strength and thermal resistance, indicating the need for careful optimization of plasticizer content depending on the end-use application [6]. Natural fiber reinforcements, such as cellulose and bamboo fibers, were also explored. SEM analysis of PLA-fiber composites showed improved interfacial bonding, which contributed to a balanced enhancement in both mechanical strength and biodegradability. The addition of natural fibers not only provided structural support but also acted as nucleating agents, promoting crystallinity and improving thermal behavior [7]. Thermal characterization through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) demonstrated that the modified PLA formulations maintained thermal stability within a range suitable for most packaging applications. The glass transition temperature (Tg) slightly decreased with plasticizer addition, which further supports the increased chain mobility and ductility of the polymer matrix [8].

In biodegradability studies under industrial composting conditions, PLA-based composites showed significantly faster degradation rates compared to traditional plastics. The presence of natural fillers further accelerated the breakdown process due to their hydrophilic nature, which enhances moisture uptake and microbial activity [9]. While the modified PLA composites show great promise for sustainable packaging, some challenges remain. These include the need to improve moisture and gas barrier properties for food packaging, the scalability of material production, and the economic competitiveness of PLA compared to petroleum-based plastics [10]. Future work should focus on advanced composite formulations, barrier property enhancements, and life cycle assessments to ensure that PLA-based packaging solutions are both effective and environmentally sound.

Conclusion

PLA-based renewable polymers hold significant promise as sustainable alternatives to petroleum-based plastics in the packaging industry. This study demonstrated that through proper formulation and processing techniques, PLA's inherent limitations such as brittleness and slow degradation under ambient conditions can be mitigated. The resulting composites exhibited improved mechanical properties and environmental performance. Future work may focus on further enhancing barrier properties, cost-effectiveness, and large-scale industrial processing techniques. Overall, PLA presents a viable path toward reducing plastic waste and promoting eco-friendly packaging solutions in alignment with global sustainability goals.

References

1. Tan C, Han F, Zhang S, Li P, Shang N (2021)Novel Bio-Based Materials and Applications in Antimicrobial Food Packaging: Recent Advances and Future Trends. Int J Mol Sci 22:9663-9665.

Indexed at, Google Scholar, Crossref

2. Sagnelli D, Hooshmand K, Kemmer GC, Kirkensgaard JJK, Mortensen K et al.( 2017)Cross-Linked Amylose Bio-Plastic: A Transgenic-Based Compostable Plastic Alternative. Int J Mol Sci 18: 2075-2078.

Indexed at, Google Scholar, Crossref

3. Zia KM, Zia F, Zuber M, Rehman S, Ahmad MN, et al.  (2015)Alginate based polyurethanes: A review of recent advances and perspective. Int J Biol Macromol 79: 377-387.

Indexed at, Google Scholar, Crossref

4. Raveendran S, Dhandayuthapani B, Nagaoka Y, Yoshida Y, Maekawa T, et al. (2013)Biocompatible nanofibers based on extremophilic bacterial polysaccharide, Mauran from Halomonas Maura. Carbohydr Polym 92: 1225-1233.

Indexed at, Google Scholar, Crossref

5. Wang H, Dai T, Li S, Zhou S, Yuan X, et al. (2018)Scalable and cleavable polysaccharide Nano carriers for the delivery of chemotherapy drugs. Acta Biomater 72: 206-216.

Indexed at, Google Scholar, Crossref

6. Lavrič G, Oberlintner A, Filipova I, Novak U, Likozar B, et al. ( 2021)Functional Nano cellulose, Alginate and Chitosan Nanocomposites Designed as Active Film Packaging Materials. Polymers (Basel) 13: 2523-2525.

Indexed at, Google Scholar, Crossref

7. Inderthal H, Tai SL, Harrison STL (2021)Non-Hydrolyzable Plastics - An Interdisciplinary Look at Plastic Bio-Oxidation. Trends Biotechnol 39: 12-23.

Indexed at, Google Scholar, Crossref

8. Ismail AS, Jawaid M, Hamid NH, Yahaya R, Hassan A, et al. (2021)Mechanical and Morphological Properties of Bio-Phenolic/Epoxy Polymer Blends. Molecules 26: 773-775.

Indexed at, Google Scholar, Crossref

9. Raddadi N, Fava F (2019)Biodegradation of oil-based plastics in the environment: Existing knowledge and needs of research and innovation. Sci Total Environ 679: 148-158.

Indexed at, Google Scholar, Crossref

10. Magnin A, Entzmann L, Pollet E, Avérous L (2021)Breakthrough in polyurethane bio-recycling: An efficient laccase-mediated system for the degradation of different types of polyurethanes. Waste Manag 132:23-30.

Indexed at, Google Scholar, Crossref