According to university studies, there is also a solution for the treatment of mixed plastic bottle waste

One of this year’s Academy Youth Award-winning researchers is experimenting with recycling a mixture of plastic bottles made of different materials.

“In recent years, several of my fellow researchers who have done excellent and promising scientific work have also won this award. Their success inspired me to try this opportunity, and I was proud that my application was also considered worthy of support by the jury. After the Environmental Protection Youth Career Award I won last year, this confirmed even more that I should continue this research topic,” he said. Daniel Gere, an assistant professor at the Polymer Technology Department of the BME Faculty of Mechanical Engineering (BME GPK), who won the Academic Youth Award of the Hungarian Academy of Sciences (MTA) this year. (Title of his thesis: Future challenges of recycling plastic bottles: the possibilities of compatibilization of PET and PLA).

The Academic Youth Award It was founded in 1972 by the Secretary General of the Hungarian Academy of Sciences to recognize the outstanding scientific work and results of young researchers. You can apply for the award with excellent results achieved through individual or group work in the given scientific field. The submissions are ranked by the academically competent committees of the Council of Academic Research Institutes (AKT). Based on their opinion, the AKT makes a proposal to the president of the Hungarian Academy of Sciences, who decides on the awardees. (The conditions for awarding the recognition are detailed on the MTA’s own website – ed.)

In 2024, two university researchers were honored with professional recognition. Along with Dániel Gere, he received the following award:

Miklós Horváth associate professor, Department of Building Mechanics and Mechanical Process Engineering (BME GPK)

Title of his thesis: Further development of methods for modeling the energy consumption of buildings and the solar energy production integrated into the building based on the statistical analysis of consumer patterns

In part of his research, Dániel Gere examines the possibilities of recycling petroleum-based and biopolymers. In an interview with bme.hu, he said that manufacturers working with plastic raw materials in various sectors are fortunately becoming more and more environmentally conscious. On the one hand, they manufacture their products from recycled raw materials, and on the other hand, they also use biopolymers instead of or in addition to petroleum-based plastics. Both are mainly used to make packaging materials with a short lifespan (only in circulation for a few days), which thus become waste in a very short time. According to Dániel Gere, this waste is much more valuable than simply going to the landfill, so efforts should be made to recycle it. “The recycling of petroleum-based polymers already works well, and there is already the possibility of industrial composting of biodegradable polymers, but unfortunately the population and selective waste collection are not yet prepared for the separate collection of biopolymers, which is why waste made from different raw materials can get mixed up during recycling.” – the young researcher highlighted the problem he was dealing with. Dániel Gere carried out a series of experiments in which he investigated the compatibility possibilities of mixed PET and PLA waste using different additives. During these tests, he proved that when compatibilizers are used, these material mixtures behave tough, in contrast to brittle mixtures without additives. This feature can facilitate later recycling if PET (poly(ethylene terephthalate)) and PLA (polylactic acid) bottles are mixed in the selective bins and thus recycled.

In addition to his master’s studies, Dániel Gere worked for a company that partially recycles PET bottles. In the course of its work, the material testing and development laboratory often received a product sample or bottle from the recycling plant with the request that the experts examine the material the waste is made of, whether it could cause problems or whether it is worth sorting separately before starting recycling. “From this practical situation came the dilemma, if biodegradable PLA bottles appear on the market and users throw them among PET bottles, what effect will this have on recycling. My supervisors saw a promising research opportunity in the question to be investigated, Tibor Gypsy Professor, as well as Ferenc Ronkay (titled university professor, Department of Polymer Technology, BME GPK and laboratory manager, Material Testing Laboratory of Imsys Kft.), which is why I already prepared my thesis partly on this topic. And I continued the research during my doctoral training,” Dániel Gere recalled the circumstances of getting to know his chosen research topic.

Dániel Gere feels lucky that he won the Cooperative Doctoral Scholarship in addition to his PhD studies, and thanks to the program he was able to examine the industrial applicability of compatibilized PET/PLA mixtures in addition to basic research questions. He analyzed the practical usability of non-compatibilized and compatibilized PET/PLA mixtures of different weight ratios during injection molding and blow molding plant trials at industrial partners. “During injection molding, I found that a preform can be molded from a mixture containing 10% PLA, however, this mixture is too brittle for bottle blowing, it would explode in the mold during blowing, which means that it cannot be made into a bottle. However, with the help of the recipe I developed, a bottle can be produced even from a mixture containing 15% by weight of PLA. From the production experiments based on my preliminary laboratory research, I found that it is indeed possible to recycle mixed PET and PLA waste”, presented one of the important and award-winning results of his scientific work, the young researcher of the BME GPK, who also revealed that there is still plenty of potential in his chosen topic.

He recently won the János Bolyai Research Scholarship, and was also successful in the OTKA competition. He applied for both programs with a sub-area of ​​this topic. One of the most important questions of his current research is whether it is possible to recycle the investigated PET and PLA mixtures multiple times. It constantly monitors the market of biopolymers, because in addition to PLA, many new raw materials have appeared in larger quantities, which also raise serious questions in the field of recycling.

Together with his students, they also research other areas of recycling, among other things, they investigate the home and industrial compostability of biopolymers. Together with the staff of the BME Faculty of Chemical and Bioengineering (BME VBK) Department of Organic Chemistry and Technology, they are developing trays made of highly heat-resistant, recycled PET, which can be used in a microwave oven or even in a traditional oven. Together with the staff of the Department of Organic Chemistry and Technology and the Department of Water Engineering and Water Management of the BME Faculty of Civil Engineering (BME ÉMK), they are analyzing the possibilities of recyclability of bottles and microplastics floating on rivers and collected from floodplains.

In addition to his research perspectives, we also asked Dániel Gere about his motivation. “I believe that the purpose of science is also to create products that can be used by industry. During my career so far, I have worked as an industrial engineer and as a researcher, I felt good in both places and found my calculations. For me, teaching-researcher tasks and assignments of industrial origin are equally important, I try to seize as many opportunities as possible in all areas. Since my doctoral training, I have been continuously participating in industrial R&D applications and projects related to the recycling of various plastics at the Department of Polymer Technology. I try to transfer the experiences and knowledge gained here to education. I noticed that it is much easier to maintain the attention and interest of younger students if, in addition to the theory, I also present the practical areas of application. This is what I strive for as a teacher.”

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