The Importance of Compatibilizers for Wood-Plastic Composites

Cellulose, the main component of wood powder, contains a large number of hydroxyl groups which form intermolecular or intramolecular hydrogen bonds. Those hydrogen bonds having strong polarity makes wood powder with water absorption whose rate up to 8% ~ 12%. While thermoplastics are hydrophobic because of having non-polar. As the result, the compatibility of  wood flour and plastics is poor and their interface adhesion force is very small. Using compatibilizers to modify the polymer-wood powder surface can improve their interfacial affinity, while the modified wood powder filler having the strengthening property can also well transfer the stress between filler and resin, so as to enhance the strength of composite material. Therefore, Adding thecompatibilizer for WPC is the first problem to be solved in order to obtain good properties and reach the requirements.

Adding compatibilizers is more easiest and effective method. At present, suitable compatibilizers includemaleic anhydride(MA) grafted polymer or MA copolymers. Most of these compatibilizers contain carboxyl or anhydride groups, which can produce chemical reactions with hydroxyl in wood powder, thereby reducing the polarity and moisture absorption after having good compatibility with resin.

COACE compatibilizer forWPC in details as follow.