What resin coupling agents improve interfacial adhesion in WPC composites?

Resin coupling agents play a crucial role in enhancing the interfacial adhesion between wood fibers and polymer matrices in wood-plastic composites (WPCs). These agents chemically bridge the hydrophilic wood fibers and hydrophobic polymers, improving mechanical properties and durability. Common coupling agents include maleic anhydride-grafted polyolefins (MAH-PP/PE), silanes, and isocyanates. MAH-PP/PE is widely used due to its compatibility with polypropylene and polyethylene matrices, forming covalent bonds with wood fibers. Silanes improve adhesion by creating siloxane linkages, while isocyanates enhance bonding through urethane formation. Selecting the right coupling agent depends on the polymer matrix and desired composite performance, ensuring optimal interfacial strength and long-term stability in WPC applications.