Chemical modification of montan resin by peracetic acid and agricultural application of its modified products

ABSTRACT

Montan resin (MR) is a by-product produced during the refinement process of montan wax extracted from lignite and has no usage yet. Chemical modification is an effective method to change the material property for expanding or converting the application area of the material itself. Our previous study found that the high hydrophobicity of MR is the primary limiting factor for its utilization in agriculture. Based on this point, this study attempted to chemically modify MR using the oxidation of peracetic acid, resulting that the MR hydrophilicity was significantly improved, and a water-soluble product (WSP) was obtained. The optimized oxidation conditions of MR, including the reaction temperature (X₁), reaction time (X₂), weight ratio of oxidant and montan resin (X₃), and oxidant concentration (X₄), were determined using single-factor experiments and response surface analysis. The modification degree was evaluated using elemental and oil-water partition coefficient analyses, infrared (IR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS), revealing that the oil-water partition coefficient of the modified product decreased and that the number of chemical constituents with oxygen-containing functional groups clearly increased after modification. Furthermore, the WSP was tested its effects on germination and seedling growth of the wheat seed. Compared with the control group, the WSP showed a promoting effect on the growth and germination of wheat. The WSP concentrations of 600 mg·L⁻¹ and 300 mg·L⁻¹ had the most substantial effect on the root and seedling growth of wheat, respectively.

Implications: Montan resin, a useless by-product produced from crude montan wax, was chemically modified via oxidation of peracetic acid. Its hydrophilicity was significantly improved, and a water-soluble product was obtained after the chemical modification. The optimized oxidation conditions of montan resin were determined using single-factor experiments and response surface analysis. The amount of chemical constituents with oxygen-containing functional groups increased in the modified products after modification, as determined by IR and GC-MS analysis, among other methods. The water-soluble modified product showed an obvious effect in promoting growth and germination of wheat at 600 mg·L-1 and 300 mg·L-1, respectively.

Acknowledgment

The authors thank Dr. Zhiwei Wang (Shandong Analysis and Test Center) for assisting with the elemental analysis. The financial support for this research from the National Natural Science Foundation of China (No. 21466018) is gratefully acknowledged.

Disclosure statement

The authors declare no competing financial interest.

Supplementary material

Supplemental data for this paper can be accessed on the publisher’s website.

Supporting information

Experiment parameters used in response surface analysis (Tables S1-S3) are available free of charge on the Internet.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [21466018].

Notes on contributors

Hui-Fen Zhang

Hui-Fen Zhang is a Senior Lab Master in Food Security Research Institute of Yunnan Province affiliated to Kunming University of Science and Technology, Kunming, China. She has more than twenty years teaching and research experience in chemistry, function, and application of lignite-based humic acid and montan wax.

Hao Qin

Hao Qin is a Postgraduate Student of Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China. He carried out his research in chemical modification and analysis of montan resin. He is interested in modification and analysis of natural products.

Bao-Cai Li

Bao-Cai Li is a Professor in Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China. He is a famous expert in the field of comprehensive utilization of lignite by clean and efficient ways in China. He has published a number of research papers in various journals about comprehensive utilization of lignite.

Yi Qin

Yi Qin is a Lab Master in Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China. His teaching and researching areas are chemistry, activity, and preparation technology of humic acid and montan wax extracted from lignite and other young coals.

Huan-Hong Wang

Huan-Hong Wang is a Postgraduate Student of Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China. She carried out her research in agricultural utilization of modified montan resin. She is interested in biological modification of natural products.

Bing Zhang

Bing Zhang is a Postgraduate Student of Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China. He carried out his research on chemical modification of montan resin. He is interested in isolation and identification of natural products.

Mi Zhang

Mi Zhang is a Professor in Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China. She has taught a number of courses on instrumental analysis and natural product chemistry. Her research and publication interests include chemistry and function of natural products from natural resources.