Bio-Based Polyurethane Networks Derived from Liquefied Sawdust.

Area of Science:

• Green Chemistry
• Materials Science
• Polymer Chemistry

Background:

• Unsustainable petrochemical resources are widely used in polyurethane production.
• Forestry waste presents an abundant and renewable resource for material synthesis.
• Developing eco-friendly alternatives is crucial for sustainable industrial practices.

Purpose of the Study:

• To investigate the liquefaction of forestry waste, specifically sawdust, into bio-polyols.
• To optimize the liquefaction process for efficient bio-polyol production.
• To evaluate the properties of bio-polyols and their suitability for polyurethane synthesis.

Main Methods:

• Liquefaction of wood-based biomass (sawdust) using glycerol and polyethylene glycol at varying temperatures (120-170°C).
• Analysis of bio-polyols using Fourier transform infrared spectroscopy (FTIR) for structural features, and determination of hydroxyl number, water content, and viscosity.
• Synthesis of polyurethane materials using a one-step hot-pressing method with varying bio-polyol content and NCO:OH ratios.

Main Results:

• Optimal liquefaction conditions identified as 150°C for 6 hours, yielding high biomass conversion.
• Bio-polyols exhibited high hydroxyl numbers (238-815 mg KOH/g), indicating suitability for polyurethane production.
• Synthesized polyurethane materials contained over 80 wt% bio-polyol and demonstrated a high modulus of elasticity (62-839 MPa).

Conclusions:

• Forestry waste can be effectively converted into bio-polyols via liquefaction.
• The produced bio-polyols show significant potential as sustainable substitutes for petrochemical polyols in polyurethane manufacturing.
• The developed one-step synthesis method yields high-performance polyurethane materials with tunable mechanical properties.