J. Mater. Sci. Technol. ›› 2023, Vol. 167: 82-93.DOI: 10.1016/j.jmst.2023.06.004

• Research article • Previous Articles     Next Articles

Engineering phosphorus-containing lignin for epoxy biocomposites with enhanced thermal stability, fire retardancy and mechanical properties

Anlin Zhanga,1, Jianzhong Zhanga,1, Lina Liua, Jinfeng Daia,*, Xinyu Lua, Siqi Huob,*, Min Hongb, Xiaohuan Liuc, Mark Lynchd, Xuesen Zengb, Paulomi Bureyb,d, Pingan Songb,d,*   

  1. aCollege of Chemistry and Materials Science, Zhejiang A& F University, Hangzhou 311300, China;
    bCentre for Future Materials, University of Southern Queensland, Springfield, QLD 4300, Australia;
    cCollege of Life Science, Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, China;
    dSchool of Agriculture and Environmental Science, University of Southern Queensland, Springfield, QLD 4300, Australia
  • Received:2023-04-24 Revised:2023-05-27 Accepted:2023-06-04 Published:2023-12-20 Online:2023-12-15
  • Contact: *E-mail addresses: Jinfengdai0601@zafu.edu.cn (J. Dai), Siqi.Huo@usq.edu.au (S. Huo), pingansong@gmail.com , pingan.song@usq.edu.au (P. Song)
  • About author:1These authors equally contributed to this work and are listed as co-first authors.

Abstract: Fabricating a high-performing thermoset using bio-based flame retardant is critical for the sustainable development of engineering materials with superior fire safety and robust mechanical properties. Herein, the epoxy (EP) composites with the industrial requirements are manufactured with a novel high-efficient, lignin-based flame retardant named DAL-x, which is fabricated by grafting 9, 10-dihydro-9-oxa-10-phosphaze-10-oxide (DOPO) onto lignin. The resulting DAL-x/EP composite exhibits excellent flame retardancy with a desirable UL-94 V-0 rating and a satisfactory limiting oxygen index (LOI) of 29.8% due to the appropriate phosphorus content of DAL-x with adjustable molecular chain structure. Moreover, the DAL-x/EP composite shows an unexpected improvement in the elastic modulus (∼36%) and well-preserved strength and ductility compared with those of pure EP. This work offers a feasible strategy for creating efficient bio-based flame retardants utilizing industrial waste lignin and preparing high-performance EP composites that meet the demanding requirement of fire retardancy in industries, contributing to the circular economy and sustainability.

Key words: Epoxy resin, Lignin, Flame retardancy, Thermal stability, Mechanical property