The role of mechanical action in the process of the thermomechanical isolation of lignin

Transmission electron microscopy of ultrathin sections of reed straw samples subjected to thermomechanical treatment revealed changes in the ultrastructure due to lignin isolation. It is assumed that the lignin in cell walls melts under the influence of high temperature and forms accumulations localized in the depth of the cell walls. Mechanical action exerted on the material presses the lignin with a damaged structure out of the cell walls. Pores 10-20 nm in diameter are observed in cell walls; lignin is localized on the surface of the particles in formations that are approximately 200 nm in size.