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Dar SU, Wu Z, Zhang L, Yu P, Qin Y, Shen Y, Zou Y, Poh L, Eichen Y, Achmon Y. On the quest for novel bio-degradable plastics for agricultural field mulching. Front Bioeng Biotechnol 2022; 10:922974. [PMID: 36003544 PMCID: PMC9393227 DOI: 10.3389/fbioe.2022.922974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 06/28/2022] [Indexed: 11/13/2022] Open
Abstract
Plasticulture, the practice of using plastic materials in agricultural applications, consumes about 6.7 million tons of plastics every year, which is about 2% of the overall global annual plastics production. For different reasons, plastic material used for agriculture is difficult to recycle. Therefore, most of it is either buried in fertile soils, thereby significantly causing deterioration of their properties, or, at best case, end in landfills where its half-life is measured in decades and even centuries. Hence, developing biodegradable plastic materials that are suitable for agricultural applications is a vital and inevitable need for the global human society. In our labs, two types of potentially biodegradable plastic polymer films were prepared and characterized imidazolium in terms of their bio-degradability. In the first approach, polymers made of ionic liquid monomers were prepared using photo radical induced polymerization. The second approach relies on formation of polyethylene-like n-alkane disulfide polymers from 1,ω-di-thiols through thermally activated air oxidation. These two families of materials were tested for their biodegradability in soils by using a simulation system that combines a controlled environment chamber equipped with a respirometer and a proton-transfer-reaction time of flight mass spectrometer (PTR-TOF-MS) system. This system provides a time-dependent and comprehensive fingerprint of volatiles emitted in the degradation process. The results obtained thus far indicate that whereas the ionic-liquid based polymer does not show significant bio-degradability under the test conditions, the building block monomer, 1,10-n-decane dithiol, as well as its disulfide-based polymer, are bio-degradable. The latter reaching, under basic soil conditions and in room temperature, ∼20% degradation within three months. These results suggest that by introduction of disulfide groups into the polyethylene backbone one may be able to render it biodegradable, thus considerably shortening its half-life in soils. Principal component analysis, PCA, of the data about the total volatiles produced during the degradation in soil indicates a distinctive volatile “fingerprint” of the disulfide-based bio-degradable products which comes from the volatile organic compounds portfolio as recorded by the PTR-TOF-MS. The biodegradation volatile fingerprint of this kind of film was different from the “fingerprint” of the soil background which served as a control. These results can help us to better understand and design biodegradable films for agricultural mulching practices.
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Affiliation(s)
- Sami Ullah Dar
- Biotechnology and Food Engineering, Guangdong Technion—Israel Institute of Technology, Shantou, China
- Guangdong Technion Department of Chemistry—Israel Institute of Technology, Shantou, China
| | - Zizhao Wu
- Biotechnology and Food Engineering, Guangdong Technion—Israel Institute of Technology, Shantou, China
| | - Linyi Zhang
- Biotechnology and Food Engineering, Guangdong Technion—Israel Institute of Technology, Shantou, China
| | - Peirong Yu
- Biotechnology and Food Engineering, Guangdong Technion—Israel Institute of Technology, Shantou, China
| | - Yiheng Qin
- Biotechnology and Food Engineering, Guangdong Technion—Israel Institute of Technology, Shantou, China
| | - Yezi Shen
- Biotechnology and Food Engineering, Guangdong Technion—Israel Institute of Technology, Shantou, China
| | - Yunfan Zou
- Biotechnology and Food Engineering, Guangdong Technion—Israel Institute of Technology, Shantou, China
| | - Leslie Poh
- Polymer Physics Laboratory, Department of Chemical Engineering, Guangdong Technion–Israel Institute of Technology (GTIIT), Shantou, China
| | - Yoav Eichen
- Guangdong Technion Department of Chemistry—Israel Institute of Technology, Shantou, China
| | - Yigal Achmon
- Biotechnology and Food Engineering, Guangdong Technion—Israel Institute of Technology, Shantou, China
- Faculty of Biotechnology and Food Engineering, Technion—Israel Institute of Technology, Haifa, Israel
- Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion, Guangdong Technion—Israel Institute of Technology, Shantou, China
- *Correspondence: Yigal Achmon,
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