Preparation and characterization of aliphatic chain modified lignin and its polymer blend

Abstract

The purpose of this study is to modify lignin for the better blending with the general purpose synthetic polymers. The possible advantages by using this modification would be cost reduction, the better physical properties and biodegradability. In this study, soft wood kraft lignin(Indulin AT) was used and different types of reagents were used for the modification of lignin. It was suggested that the reagents would be chemically bonded to lignin like lignin-carbohydrate-complex (LCC) structure. Several analyses were performed to chase the change of molecular structure by modification procedure. It was confirmed that the lignin is modified as expected and reaction site of modification and the reaction behaviors were varied by the reagent types. It was found that the highest yield of modification was achieved at the condition of 10:6 (reagent : lignin) charge ratio and 2hour reaction time. By the analysis of 1H-NMR, FT-IR and DSC, it was found that the lignin was modified as intended and had different character due to the types of aliphatic chain. Then the modified lignin was blended with synthetic polymers like PLA, PP and PET. The blends were characterized by using UTM, DSC and XRD to investigate the physical properties. Furthermore, the degradation test was performed in order to see if biodegradability was given by the modified lignin.