CHUNYAN LIU^*, YUNHE LIU, ZIHAN PAN, QIUTING LI, HAN XU, TAO LIU

Journal of Polymer Materials, Vol.36, No.1, pp. 87-99, 2019, DOI:10.32381/JPM.2019.36.01.7

Abstract In this work, a series of novel lignin-based bis-benzoxazine monomers were efficiently synthesized by the reaction of renewable phenols: guaiacol, vanillyl alcohol, eugenol, vanillin with ethylene diamine and paraformaldehyde. The chemical structures of these lignin-based bis-benzoxazine monomers were confirmed by ¹H-NMR, ¹³C-NMR and FTIR, indicating the formation of benzoxazine ring. The obtained bis-benzoxazine monomers were cured via thermal treatment. The curing behavior of these lignin-based bis-benzoxazine monomers were compared and analyzed via differential scanning calorimetry (DSC), showing that Va-e possessed higher ring-opening polymerization activity than G-e, while E-e and V-e had lower curing activity than G-e. More >

Yan Song^1,2, Zhixin Wang³, Xin Zhang⁴, Rong Zhang¹, Jinchun Li^1,2,*

Journal of Renewable Materials, Vol.9, No.5, pp. 943-957, 2021, DOI:10.32604/jrm.2021.014131

Abstract Lignin is a natural biopolymer with a complex three-dimensional network, commercially obtained from waste liquid of paper pulp and bioethanol production, and could be a candidate for preparation of environment-friendly bio-based polyphenol material. In the present work, the demethylated wheat straw alkali lignin (D-Lig), prepared by demethylation of wheat straw alkali lignin (Lig) using an in-situ generated Lewis acid, was used to synthesize bio-based phenol formaldehyde resin adhesive (D-LPF) applied in plywood. Effects of synthetic process’s factors, including lignin substitution for phenol, NaOH concentration and molar ratio of formaldehyde to phenol, on the bonding strength and free formaldehyde content of… More >