Open Access

ARTICLE

Formaldehyde Free Renewable Thermosetting Foam Based on Biomass Tannin with a Lignin Additive

by Bowen Liu¹, Yunxia Zhou¹, Hisham Essawy², Shang Feng¹, Xuehui Li¹, Jingjing Liao¹, Xiaojian Zhou^1,3,*, Jun Zhang^1,*, Sida Xie¹

1 Yunnan Provincial Key Laboratory of Wood Adhesives and Glued Products, Southwest Forestry University, Kunming, 650224, China
2 Department of Polymers and Pigments, National Research Centre, Cairo, 12622, Egypt
3 Key Laboratory for Forest Resources Conservation and Utilisation in the Southwest Mountains of China (Southwest Forestry University), Ministry of Education, Kunming, 650224, China

* Corresponding Authors: Xiaojian Zhou. Email: ; Jun Zhang. Email:

(This article belongs to the Special Issue: Renewable Foam Materials and Composites)

Journal of Renewable Materials 2022, 10(11), 3009-3024. https://doi.org/10.32604/jrm.2022.019848

Received 19 October 2021; Accepted 01 December 2021; Issue published 29 June 2022

Abstract

This study presents easily prepared free formaldehyde bio-based foam based on a prepared thermosetting resin comprising tannin–lignin–furfuryl alcohol-glyoxal (TLFG) via mechanical stirring in presence of ether as a foaming agent. The foam was developed through a co-polycondensation reaction of glyoxal and furfuryl alcohol with condensed tannin and lignin, which is a forest-derived product. Investigation using scanning electron microscopy (SEM) showed more closed-cell structure without cracks and collapse in the TLFG foam, with a higher apparent density with respect to tannin–furanic–formaldehyde (TFF) foam. Differential scanning calorimetry (DSC), dynamic thermomechanical analysis (DTMA), and thermogravimetric analysis (TGA) investigations revealed that the curing process of TLFG foam proceeds easily even at a lower temperature. Additionally, it acquired higher heat resistance than TFF foam. Moreover, TLFG has a more robust chemical network structure, which contributes efficiently to the mechanical strength and a lower pulverization degree compared with TFF-derived foam. Fourier transform infrared spectrometry (FTIR) and electrospray ionization mass spectrometry (ESI-MS) proved that the cross-inking reactions between tannin, lignin, furfuryl alcohol, and glyoxal have been proceeded efficiently.

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Keywords

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