Latest News Archive

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

Producers to save thousands with routine marketing strategies, says UFS researcher
2014-09-01

 

Photo: en.wikipedia.org

Using derivative markets as a marketing strategy can be complicated for farmers. The producers tend to use high risk strategies which include the selling of the crop on the cash market after harvest; whilst the high market risks require innovative strategies including the use of futures and options as traded on the South African Futures Exchange (SAFEX).

Using these innovative strategies are mostly due to a lack of interest and knowledge of the market. The purpose of the research conducted by Dr Dirk Strydom and Manfred Venter from the Department of Agricultural Economics at the University of the Free State (UFS) is to examine whether the adoption of a basic routine strategy is better than adopting no strategy at all.

The research illustrates that by using a Stochastic Efficiency with Respect to a Function (SERF) and Cumulative Distribution Function (CDF) that the use of five basic routine marketing strategies can be more rewarding. These basic strategies are:
• Put (plant time)
• Twelve-segment pricing
• Three-segment pricing
• Put (pollination)(Critical Moment in production/marketing process), and
• Pricing during pollination phase.

These strategies can be adopted by farmers without an in-depth understanding of the market and market-signals. Farmers can save as much as R1.6 million per year on a 2000ha farm with an average yield.

The results obtained from the research illustrate that each strategy is different for each crop. Very important is that the hedging strategies are better than no hedging strategy at all.

This research can also be applicable to the procurement side of the supply chain.

Maize milling firms use complex procurement strategies to procure their raw materials, or sometimes no strategy at all. In this research, basic routine price hedging strategies were analysed as part of the procurement of white maize over a ten-year period ranging from 2002–2012. Part of the pricing strategies used to procure white maize over the period of ten years were a call and min/max strategy. These strategies were compared to the baseline spot market. The data was obtained from the Johannesburg Stock Exchange’s Agricultural Products Division better known as SAFEX.

The results obtained from the research prove that by using basic routine price-hedging strategies to procure white maize, it is more beneficial to do so than by procuring from the spot market (a difference of more than R100 mil).

Thus, it can be concluded that it is not always necessary to use a complex method of sourcing white maize through SAFEX, to be efficient. By implementing a basic routine price hedging strategy year on year it can be better than procuring from the spot market.

Understanding the Maize Maze by Dr Dirk Strydom and Manfred Venter (pdf) - The Dairy Mail


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