Amir Nemati Hayatia, David A. C. Evansa, Bronwyn Laycockb, Darren J Martina and Pratheep Kumar Annamalaia,*

a The University of Queensland, Australian Institute for Bioengineering and Nanotechnology, Brisbane, Queensland 4072, Australia
b The University of Queensland, School of Chemical Engineering, UQ-Dow centre for sustainable engineering and innovation, Brisbane, Queensland 4072, Australia


Lignin, which is an inexpensive renewable aromatic biopolymer, is annually produced at about 70 million tonnes. From this, only about 5 % is so far utilised in high-value applications.1 As an abundant raw material that contains a considerable amount of aliphatic and aromatic hydroxyl groups, lignin can be utilised in high-performing polymeric materials, provided that its functional groups are made accessible. Rigid polyurethane foam (RPUF) is the most efficient and commercially sought material for the thermal insulation, appliances and construction industry. The conventional approach for lignin incorporation in RPUF mainly relies on physical mixing of lignin microparticles as “reactive fillers” at high loadings with other foam making components. However, this approach leads to formation of RPUF having inferior mechanical and thermal insulation features compared to their counterparts based on petrochemical polyols.  Our investigation aimed to exploit the full potential of lignin by improving its solubility and dispersion in the polyol components. 4 The proposed methodology in this study relies on processing the kraft lignin with the polyol components at a temperature below the glass transition temperature of lignin (120 °C). Results indicate that the enhanced dissolution and dispersion of lignin originating from the high temperature processing results in improvement in ‘both’ the compressive mechanical properties and thermal insulation features of the RPUF. The full-paper presentation will include the detailed processing methodology, its influences on the polyol/lignin dispersion, morphological evolutions and the performance of the resultant RPUF.


  1. Lievonen, M.; Valle-Delgado, J. J.; Mattinen, M.-L.; Hult, E.-L.; Lintinen, K.; Kostiainen, M. A.; Paananen, A.; Szilvay, G. R.; Setala, H.; Osterberg, M., A simple process for lignin nanoparticle preparation. Green Chem 2016, 18 (5), 1416-1422.
  2. Pan, X. J.; Saddler, J. N., Effect of replacing polyol by organosolv and kraft lignin on the property and structure of rigid polyurethane foam. Biotechnol Biofuels 2013, 6.
  3. Xue, B. L.; Wen, J. L.; Sun, R. C., Lignin-Based Rigid Polyurethane Foam Reinforced with Pulp Fiber: Synthesis and Characterization. Acs Sustain Chem Eng 2014, 2 (6), 1474-1480.
  4. Nemati Hayati A; Evan DAC; Laycock B; Martin DJ; Annamalai PK, Chemical Engineering Journal 2017, submitted.