image: PLA is a biodegradable polymer made from renewable plant sources, which can be used to make mask production more environmentally-friendly. view more
Credit: 123RF
Researchers in Singapore from the Agency for Science, Technology and Research's (A*STAR) Institute of Materials Research and Engineering (IMRE) and Nanyang Technological University (NTU) have found that Polylactic Acid (PLA), a biodegradable polymer made from renewable plant sources, is a promising sustainable alternative to the fossil-based polymers made from non-renewable petrochemicals that are currently used in the production of non-woven face masks to combat COVID-19.
Published in Science of The Total Environment on 19 October 2021, the study tested the degradability of pure PLA-derived 3-ply disposable face masks for hydrolytic degradation and biodegradation under ambient temperatures.
The team observed that the face masks undergo rapid hydrolytic degradation under basic conditions, with a sharp 25 per cent decrease in weight in the first week. In particular, the middle meltblown layer of the face mask, experienced more degradation than the outer and inner spunbond layers. Through scanning electron microscopy (SEM), it was discovered that the PLA fibers in the middle meltblown layer are 3 times thinner than the fibers in the outer and inner spunbond layers, which led to greater degradation.
Additionally, the mask layers were also able to biodegrade to small oligomer fragments in the presence of micro-organisms, with the solubilised fragments fully bio-mineralised without the formation of secondary microplastic pollution.
The study paves the way for future research to explore alternative materials with higher degradability and optimal conditions for the degradation of face mask materials into non-harmful components, while maintaining durability, filtration and protection properties for users.
“Our findings on the degradation results of PLA masks are highly encouraging. They are a step in the right direction towards discovering more sustainable materials for personal protective equipment in times of pandemic”, said Ms Soo Xiang Yun Debbie, a researcher from the department of Advanced Characterisation and Instrumentation (ACI) at IMRE.
“The degradation results of the PLA masks have provided us with ideas on how to design more degradable polymers. Encouraged by this, we have started more collaborations with the researchers from the local research ecosystem and companies so that we can develop solutions to tackle waste challenges arising from mask disposal”, said Dr Zhu Qiang, Department Head of Advanced Characterization and Instrumentation (ACI) at IMRE.
About the Agency for Science, Technology and Research (A*STAR)
The Agency for Science, Technology and Research (A*STAR) is Singapore's lead public sector R&D agency. Through open innovation, we collaborate with our partners in both the public and private sectors to benefit the economy and society. As a Science and Technology Organisation, A*STAR bridges the gap between academia and industry. Our research creates economic growth and jobs for Singapore, and enhances lives by improving societal outcomes in healthcare, urban living, and sustainability. A*STAR plays a key role in nurturing scientific talent and leaders for the wider research community and industry. A*STAR’s R&D activities span biomedical sciences to physical sciences and engineering, with research entities primarily located in Biopolis and Fusionopolis. For ongoing news, visit www.a-star.edu.sg.
About Nanyang Technological University (NTU)
A research-intensive public university, Nanyang Technological University, Singapore (NTU Singapore) has 33,000 undergraduate and postgraduate students in the Engineering, Business, Science, Humanities, Arts, & Social Sciences, and Graduate colleges. It also has a medical school, the Lee Kong Chian School of Medicine, set up jointly with Imperial College London. NTU is also home to world-class autonomous institutes – the National Institute of Education, S Rajaratnam School of International Studies, Earth Observatory of Singapore, and Singapore Centre for Environmental Life Sciences Engineering – and various leading research centres such as the Nanyang Environment & Water Research Institute (NEWRI) and Energy Research Institute @ NTU (ERI@N). Ranked amongst the world's top universities by QS, NTU has been placed the world's top young university for the past seven years. The University's main campus is frequently listed among the Top 15 most beautiful university campuses in the world and it has 57 Green Mark-certified (equivalent to LEED-certified) building projects, of which 95% are certified Green Mark Platinum. Apart from its main campus, NTU also has a campus in Novena, Singapore's healthcare district. For more information, visit https://www.ntu.edu.sg.
Journal
Science of The Total Environment
Article Title
Polylactic acid face masks: Are these the sustainable solutions in times of COVID-19 pandemic?
Article Publication Date
19-Oct-2021