Mild chemical modification of acetosolv lignin from several Chilean sources

GARCÍA, D.; FUENTEALBA, C.; PÉREZ, M.; SALAZAR, J.; GLASSERC, W.:
3^er Congreso Iberoamericano sobre Biorrefinerías (CIAB), 4^to Congreso Latinoamericano sobre Biorrefinerías y 2^do Simposio Internacional sobre Materiales Lignocelulósicos. Abstract book pp 124-125 (2015).

Abstract

Lignin is the most abundant aromatic bio-polymer in nature. However, applications of lignin as building-blocks in material science is affected by several drawbacks. In order to tailor selected properties a mild modification at room temperature (22 °C) was carried out. Acetosolv lignin from Pinus sp., Triticum sp., and Eucalyptus sp. were modified with propylene oxide for 24 hours in alkaline media (pH: 12). Physico-, chemical-, and biological-properties were evaluated. Regardless lignin source hydroxypropyl-lignin (HPL) were synthetized in a high yield (87-96%). Strong structure-property relationship was stablished in function of monolignol units. H-NMR provide valuable insight regarding reaction efficiency ratio associated to the Syringyl/Guaiacyl ratio. Hydroxypropylation affects solubility, antioxidant activity, and the thermal behaviour. However, changes upon derivatization were related to the specific source and composition. Modified Acetosolv lignin from Chilean sources possess properties that are expected to enhance their role in new polymerization pathways for material engineering.