Latest News Archive

Please select Category, Year, and then Month to display items

Research into biodegradable polymers helps fight plastic pollution

02 September 2024 | Story André Damons | Photo Supplied

Dr Puseletso Mofokeng — Dr Julia Puseletso Mofokeng, from the UFS’s Department of Chemistry, is doing research into biodegradable polymers for application in disposable product packaging.

A researcher from the University of the Free State (UFS) is contributing to the fight against plastic pollution through her research into biodegradable polymers – large, chain-like molecules – as a more environmentally friendly alternative to petroleum-based plastics.

Plastic pollution is a global environmental problem, with 19 to 23 million tonnes of plastic waste leaked into aquatic ecosystems every year.

Dr Julia Puseletso Mofokeng, Senior Lecturer and Researcher in the UFS Department of Chemistry, hopes her research into how biodegradable polymers can be used in disposable product packaging can influence the industry and policymakers to enforce the use of biopolymers or biodegradable polymers in disposable products. This would help reduce plastic waste and boost environment-conservation efforts.

The United Nations Environment Programme (UNEP) describes plastic waste as a serious environmental problem – humans produce about 400 million tonnes of plastic waste every year. Approximately 36% of all plastics produced are used in packaging, including single-use plastic products for food and beverage containers, approximately 85% of which ends up in landfills or as unregulated waste.

Researching biodegradable polymers

Dr Mofokeng’s desire to solve the waste problem in her community of Bophelong village in Qwaqwa, Free State – where community members dumped and burned all sorts of waste, including plastics – inspired her towards her field of research.

Today, her research is aimed at managing plastic waste to combat environmental and atmospheric pollution (from incineration), conserve energy, and improve water quality, including ensuring safe drinking water.

High levels of plastic waste have led to increased research into and development of biodegradable polymers as an alternative to non-biodegradable materials for short-shelf-life goods (such as packaging for fresh fruit and vegetables).

Biopolymers or biodegradable polymers, explains Dr Mofokeng, are derived from renewable resources including, but not limited to, vegetable oils, starches and animal fats. They can therefore be easily disposed of after use without harming the environment.

“My research is based on the preparation and characterisation of completely biodegradable polymers, their blends, and composites or nanocomposites filled with unmodified or modified inorganic fillers, natural fibres, as well as synthesised carbonaceous materials,” she says.

Such materials are developed for various applications, including packaging, electromagnetic interference shielding (blocking unwanted signals), and the removal of heavy metals and other contaminants from water bodies.

“To achieve these aims, I and my small research group are preparing completely biodegradable polymer blends.”

This involves adjusting their morphology (structure) and some of their properties (thermal, thermomechanical, mechanical, and flame retardancy) to match those of petroleum-based polymers in their replacement for disposable products; by reinforcing with natural fibres, and minerals.

Biodegradable polymers can degrade within a few days to a few years depending on their source, type, and biodegradation method used, while petroleum-based polymers can exist for hundreds to thousands of years without degrading. Moreover, because biodegradable polymers are produced from natural resources, their biodegradation mainly produces carbon dioxide, water, and other non-toxic byproducts, Dr Mofokeng adds.

“Biodegradable polymers can degrade by themselves under natural environmental conditions – in one to three years – or may require human intervention to degrade where composts are prepared or conditions are controlled in order to degrade the polymers. The latter two being the fastest, where it could take days to months. In my previous research project [we] kept polylactic acid filled with short sisal fibre in plain water at 80℃, and all the tested samples degraded within 10 days.”

She and a PhD student are conducting an ongoing experiment involving three different biodegradable polymer systems exposed to different conditions outside and under soil, measuring the rate of biodegradation by mimicking the environmental conditions found in dumping sites and landfills.

Signs of biodegradation on the samples showed clearly after 14 months, with cracks, surface erosion, and a decrease in the initial weighed mass, suggesting that the polymers could be completely degraded within two to three years.

Closer to goal

Dr Mofokeng, who has been a National Research Foundation (NRF) Y2-rated researcher since 2021, says since most food outlets and restaurants in South Africa have already started using paper- and bio-based polymer materials in cutlery, straws, and takeaway packaging, the country seems to be closer to its goal of using biodegradable polymers for disposable packaging.

The UFS, too, is aiming to phase out the use of plastic bottles in the next three to five years. This will be done by installing filtered water machines in all its buildings.

“We are now left with policymakers to enforce strict laws governing production; and retail industries to use biopolymers or biodegradable polymers in disposable packaging materials,” she says.

New research

Dr Mofokeng and her group’s research is in line with the United Nations’ Sustainable Development Goals (SDGs), including ensuring good health and wellbeing (SDG3), providing clean water and sanitation (SDG6), forging sustainable cities and communities (SDG11), establishing sustainable consumption and production patterns (SDG12), and protecting life below water (SDG14).

She has been researching polymers for almost two decades, and remains passionate about her research field and educating communities. Her new research project, in collaboration with colleagues from her department, targets the removal of heavy metals and other contaminants from groundwater. Testing and water treatment is set to take place in different regions in Qwaqwa, specifically among households that collect drinking and cooking water from boreholes.

Dr Mofokeng’s research group was established in 2016 with one honours and two master’s students. She has since supervised nine honours, seven master’s and one PhD student.

She also recently established international research collaborations with the Libyan Advanced Center for Chemical Analysis and the Faculty of Technology at the University of Banja Luka in Serbia.

News Archive

“To forgive is not an obligation. It’s a choice.” – Prof Minow during Reconciliation Lecture

2014-03-05

“To forgive is not an obligation. It’s a choice.” – Prof Minow during the Third Annual Reconciliation Lecture entitled Forgiveness, Law and Justice.
Photo: Johan Roux

No one could have anticipated the atmosphere in which Prof Martha Minow would visit the Bloemfontein Campus. And no one could have predicted how apt the timing of her message would be. As this formidable Dean of Harvard University’s Law School stepped behind the podium, a latent tension edged through the crowded audience.

“The issue of getting along after conflict is urgent.”

With these few words, Prof Minow exposed the essence of not only her lecture, but also the central concern of the entire university community.

As an expert on issues surrounding racial justice, Prof Minow has worked across the globe in post-conflict societies. How can we prevent atrocities from happening? she asked. Her answer was an honest, “I don’t know.” What she is certain of, on the other hand, is that the usual practice of either silence or retribution does not work. “I think that silence produces rage – understandably – and retribution produces the cycle of violence. Rather than ignoring what happens, rather than retribution, it would be good to reach for something more.” This is where reconciliation comes in.

Prof Minow put forward the idea that forgiveness should accompany reconciliation efforts. She defined forgiveness as a conscious, deliberate decision to forego rightful grounds of resentment towards those who have committed a wrong. “To forgive then, in this definition, is not an obligation. It’s a choice. And it’s held by the one who was harmed,” she explained.

Letting go of resentment cannot be forced – not even by the law. What the law can do, though, is either to encourage or discourage forgiveness. Prof Minow showed how the law can construct adversarial processes that render forgiveness less likely, when indeed its intention was the opposite. “Or, law can give people chances to meet together in spaces where they may apologise and they may forgive,” she continued. This point introduced some surprising revelations about our Truth and Reconciliation Commission (TRC).

Indeed, studies do report ambivalence, disappointment and mixed views about the TRC. Whatever our views are on its success, Prof Minow reported that people across the world wonder how South African did it. “It may not work entirely inside the country; outside the country it’s had a huge effect. It’s a touchstone for transitional justice.”

The TRC “seems to have coincided with, and maybe contributed to, the relatively peaceful political transition to democracy that is, frankly, an absolute miracle.” What came as a surprise to many is this: the fact that the TRC has affected transitional justice efforts in forty jurisdictions, including Rwanda, Sierra Leone, Cambodia and Liberia. It has even inspired the creation of a TRC in Greensborough, North Carolina, in the United States.

There are no blueprints for solving conflict, though. “But the possibility of something other than criminal trials, something other than war, something other than silence – that’s why the TRC, I think, has been such an exemplar to the world,” she commended.

Court decision cannot rebuild a society, though. Only individuals can forgive. Only individuals can start with purposeful, daily decisions to forgive and forge a common future. Forgiveness is rather like kindness, she suggested. It’s a resource without limits. It’s not scarce like water or money. It’s within our reach. But if it’s forced, it’s not forgiveness.

“It is good,” Prof Minow warned, “to be cautious about the use of law to deliberately shape or manipulate the feelings of any individual. But it is no less important to admit that law does affect human beings, not just in its results, but in its process.” And then we must take responsibility for how we use that law.

“A government can judge, but only people can forgive.” As Prof Minow’s words lingered, the air suddenly seemed a bit more buoyant.

Back

Economic and Management Sciences

Education

Health Sciences

The Humanities

Law

Natural and Agricultural Sciences

Theology and Religion

Open Distance Learning

Business School

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept