Lignin – Renewable resource for polymer materials

Lignin, the second major component of wood and annual plants, is a highly branched and irregular macromolecule, whose structure (fig.1) based on phenylpropanoic units varies with the vegetable species and the method of isolation.

Lignin, the second major component of wood and annual plants, is a highly branched and irregular macromolecule, whose structure (fig.1) based on phenylpropanoic units varies with the vegetable species and the method of isolation.


 

Being an abundant and renewable polymer, much effort has been made in the last decades to modify lignin so that it can be incorporated in polymeric material and thus used in applications of higher value. The reaction of lignin with propylene oxide (oxypropylation, fig.2) is an established method to overcome technical limitations and adverse effects resulting from the polymeric nature of lignin when directly used for synthesis purposes. [1]

 

Being an abundant and renewable polymer, much effort has been made in the last decades to modify lignin so that it can be incorporated in polymeric material and thus used in applications of higher value. The reaction of lignin with propylene oxide (oxypropylation, fig.2) is an established method to overcome technical limitations and adverse effects resulting from the polymeric nature of lignin when directly used for synthesis purposes. [1]


Oxypropylation increases the reactivity of lignin’s functional groups and improves its solubility and uniformity. Such formed low-cost polyols from renewable resources might be able to replace conventional polyols in the polyurethane industry if they possess a certain viscosity and hydroxyl index. [1]

Our research work focuses on varying the properties of the polyols obtained and testing them for the manufacture of polyurethanes, in particular rigid polyurethane foams. Additionally other applications of lignin itself and lignin polyols are evaluated.

[1] K. Wallisch, D. Dautefendic, S. Knaus: "Synthesis and Characterization of Oxypropylated Lignins"; Poster: 19th Annual Meeting of the BioEnvironmental Polymer Society (BEPS), Wien; 28.09.2011 - 30.09.2011; in: "19th Annual Meeting of the BioEnvironmental Polymer Society", (2011), ISBN: 978-3-9502992-3-6; S. 40.

Oxypropylation increases the reactivity of lignin’s functional groups and improves its solubility and uniformity. Such formed low-cost polyols from renewable resources might be able to replace conventional polyols in the polyurethane industry if they possess a certain viscosity and hydroxyl index. [1]

Our research work focuses on varying the properties of the polyols obtained and testing them for the manufacture of polyurethanes, in particular rigid polyurethane foams. Additionally other applications of lignin itself and lignin polyols are evaluated.

[1] K. Wallisch, D. Dautefendic, S. Knaus: "Synthesis and Characterization of Oxypropylated Lignins"; Poster: 19th Annual Meeting of the BioEnvironmental Polymer Society (BEPS), Wien; 28.09.2011 - 30.09.2011; in: "19th Annual Meeting of the BioEnvironmental Polymer Society", (2011), ISBN: 978-3-9502992-3-6; S. 40.