On the Design of Novel Biofoams Using Lignin, Wheat Straw, and Sugar Beet Pulp as Precursor Material

Surojit Gupta; Maharshi Dey; Sabah Javaid; Yun Ji; Scott Payne

doi:10.1021/acsomega.0c00721

On the Design of Novel Biofoams Using Lignin, Wheat Straw, and Sugar Beet Pulp as Precursor Material

ACS Omega. 2020 Jul 7;5(28):17078-17089. doi: 10.1021/acsomega.0c00721. eCollection 2020 Jul 21.

Authors

Surojit Gupta¹, Maharshi Dey¹, Sabah Javaid², Yun Ji³, Scott Payne⁴

Affiliations

¹ Department of Mechanical Engineering, University of North Dakota, Grand Forks, North Dakota 58201, United States.
² Biomedical Engineering Program, School of Computer Science and Electrical Engineering, University of North Dakota, Grand Forks, North Dakota 58201, United States.
³ Department of Chemical Engineering, University of North Dakota, Grand Forks, North Dakota 58201, United States.
⁴ NDSU Electron Microscopy Center, North Dakota State University, Fargo, North Dakota 58102, United States.

Abstract

In this paper, we report the synthesis and characterization of pyrolyzed lignin compacts reinforced with 50 wt % wheat straw (WS) or sugar beet pulp (SBP) fibers. The compacts were pyrolyzed at 300, 500, 700, and 900 °C in an Ar atmosphere. Detailed thermogravimetric analysis (TGA), thermomechanical analysis (TMA), Fourier transform infrared (FTIR) spectroscopy, and microstructure analysis were performed on these samples. FTIR analysis showed that pyrolysis of lignin-WS and lignin-SBP resulted in aromatic char. Scanning electron microscope (SEM) studies showed that foams obtained by pyrolyzing both lignin-50 wt % SBP and lignin-50 wt % WS composites have a cellular structure. X-ray tomography and energy-dispersive spectrometry (EDS) studies showed that pyrolysis of wheat straw caused the formation of mineral-rich nodules in the pyrolyzed lignin matrix, which was responsible for the denser and uniform microstructure of the lignin-WS composites. Due to this reason, the lignin-WS composites were denser and had a better mechanical strength as compared to the lignin-SBP composites. Both the compositions also showed temperature-dependent wettability behavior.