TY  - EJOU
AU  - Shkuro, Alexey E. 
AU  - Artyomov, Artyom V. 
AU  - Buryndin, Victor G. 
AU  - Ershova, Anna S. 
AU  - Yakubova, Tatyana V. 

TI  - Formation of Binder-Free Composites Based on Natural Materials: Structure, Mechanisms, and Prospects for Chemical Modification
T2  - Journal of Renewable Materials

PY  - 
VL  - 
IS  - 
SN  - 2164-6341

AB  - Binder-free lignocellulosic boards and molded composites are gaining momentum as low-emission alternatives to conventional wood-based panels because they exploit intrinsic self-bonding of biomass under hot pressing. This review critically analyzes structure-formation pathways in binder-free composites, focusing on (i) thermo-mechanical softening and flow of lignin as a natural adhesive phase, (ii) auto-hydrolysis of hemicelluloses generating organic acids and reactive furanic intermediates, and (iii) subsequent condensation and crosslinking reactions that consolidate the network. We compare process routes historically associated with Masonite-type fiber processing and Lignoplast-type direct compaction, highlighting how moisture, temperature, pressure, sealing degree, and particle morphology govern bond development and dimensional stability. Particular attention is paid to chemical activation strategies (oxidants, nitrogen-containing reagents, and reactive bio-based systems) that tune lignin mobility and reactivity, enabling milder pressing and improved water resistance. We outline research gaps linking chemical transformations to macroscopic performance, and propose future directions including <i>in situ</i> monitoring, quantitative structure-property models, and activation chemistries compatible with circular and compostable product concepts.
KW  - Binder-free composites; self-bonding; lignin activation; hot pressing; steam explosion; lignocellulosic composites; moisture sensitivity

DO  - 10.32604/jrm.2026.02025-0194