Why Such a Task

based on polyolefins, have one principal problem related to their integrity It is commonly a blend of a hydrophobic plastic and hydrophilic wood (or hydrophilic cellulosic fiber). Hence, the adhesion between them is poor, the interface between plastic and wood filler is typically weak, and it fails to optimally transfer stress between the two phases, when loaded. Lubricants help to solve the problem however, there are means to further improve bridging the interface by employing other mechanisms. 

In order to implement those means as fully as possible, two issues should be solved (1) distribute the filler in the plastic matrix as uniformly as possible, and 

Studies into the matter have shown that a proper coupling agent should contain two functional domains One domain capable to form entanglements, or segmental crystallization with the polymer matrix and the other capable to strongly interact with the hller—via covalent bond(s), ionic interactions, hydrogen bonds, and so on. These interactions commonly increase the interface adhesion between the hller and the matrix. 

The above is essentially a theoretical basis for coupling agents for WPC, consisting in an ideal case of two domains, that is, a chemically reactive group capable to interact with cellulose and a polymeric chain capable to entangle with matrix polymers, as it was described above. 

---