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

Teachers should deal with diversity in education - Prof. Francis

2010-10-08

At the occasion were, from the left: Prof. Jonathan Jansen, Rector and Vice-Chancellor of the University of the Free State (UFS); Prof. Francis; and Prof. Driekie Hay, Vice-Rector: Teaching and Learning at the UFS.
Photo: Jaco van der Merwe

Prof. Dennis Francis, the Dean of the Faculty of Education at the University of the Free State (UFS), recently delivered his inaugural lecture on Troubling Diversity in South African Education on the Main Campus in Bloemfontein.

He urged teachers to be open to what “diversity” might mean in a particular context and how diversity relates to either inclusion or exclusion.

“An approach that promotes the inclusion of all must be based on an understanding of how exclusion operates in ways that may have typical patterns of oppression, but differ in the specific ways that exclusion is expressed and becomes normalised in that context,” he said.

“The good teacher thus seeks to understand how these forms of exclusion may develop in the school’s context and respond through taking thoughtful action to challenge them. It may require creating a climate that enables the silent to speak and recognising that not all groups communicate in exactly the same ways.”

He said teachers also had to affirm the experiential base of learners and students. He said there was an assumption that students would be more effective practitioners if their own experience were validated and explored.

“It is crucial that the students’ own history is treated as valuable and is a critical part of the data that are reflected,” he said. “Equally important is that such stories and similar activities are intentionally processed to enable students to make the connections between personal experience and relevant theory.”

He also urged them to challenge the ways in which knowledge had been framed through oppression.

“Schools are often characterised by messages that draw on one or another form of oppression. Thus, expectations are subtly or in some cases unsubtly communicated, e.g. that girls are not good at physics, or that, while white learners are strong in abstract thought, African learners have untapped creativity, and so on,” he continued.

“For someone to integrate into their role as educators a commitment against oppression means confronting obstacles that one may previously have shied away from, such as challenging authority, naming privilege, emphasising the power relations that exist between social groups, listening to people one has previously ignored, and risking being seen as deviant, troublesome or unpopular.”

Furthermore, Prof. Francis said dealing with diversity in education was always affectively loaded for both students and teachers. He said in South Africa one injunction from educators was to be “sensitive” and thus avoid risking engagement with the contentious issues around imbalances of power.

“If both students and teachers are to confront issues of oppression and power in any meaningful way, we need to design more purposely for the difficulties they will encounter, for example, creating a classroom environment that promotes safety and trust so that all students are able to confront and deal with prejudice and discrimination. Classroom environments will need to balance the affective and cognitive in addressing issues of diversity and social justice,” he added.

He also said that teachers should recognise the need to complement changing attitudes with attempts to change the structural aspects of oppressions.

“To prevent superficial commitments to change, it is important for students to explore barriers that prevent them from confronting oppressive attitudes and behaviours. In this way students are able to learn and see the structural aspects of oppression,” he said.

“Equally important, however, is to get students to examine the benefits associated with challenging oppression. A fair amount of time must therefore be spent on developing strategies with students which they will be able to use practically in challenging oppression.”

He also advised educators to affirm the capacity of staff and learners to act and learn in ways that do not replicate patterns of oppression.

“Many South African schools have survived both the harsh repression of apartheid and the continuing legacy of oppression of various kinds. Despite that, we are often as educators made aware of the ways in which young people in particular affirm themselves and each other in creative and confident ways,” he concluded.

Media Release
Issued by: Lacea Loader
Director: Strategic Communication (acg)
Tel: 051 401 2584
Cell: 083 645 2454
E-mail: loaderl@ufs.ac.za
7 October 2010

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