Miscible raw lignin/nylon 6 blends: Thermal and mechanical performances

ABSTRACT Environmentally friendly bio‐filled composites of various proportions of polyamide 6 (PA6) and technical lignin have been prepared using a twin‐screw extruder. Transmission electron microscopy has been used to investigate the morphology of the composites. It reveals homogeneous single phase system, indicating the miscibility of PA6 and lignin. The glass transition temperature of the blends, determined by DMA, was shifted systematically to higher temperature with increasing concentration of lignin which highlights the miscibility of both components. In addition, Fourier Transform Infrared analyses have shown that new specific hydrogen‐bonding interactions are formed between hydroxyl groups of lignin and amine groups of the PA6. The presence of these intermolecular interactions between PA6 and lignin strongly influenced the thermal stability of the blends by lowering the onset of the blend's degradation process. However, the blends exhibit good mechanical properties whatever the lignin content. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42963.