Compared with conventional and mineral filler reinforced thermoplastic products, wood–polymer composites (WPC) have many advantages such as high specific strength and modulus, low cost, low density, and low friction during compounding. Unlike wood, WPC have excellent dimensional stability under moisture exposure [1, 2] and better fungi and termite resistance [3, 4]. For WPC, one of the most attractive features is that it can help recycle thermoplastic and wood wastes. Therefore, WPC have developed quickly in the last three decades [5]. However, polar wood fiber and non-polar thermoplastics and commodity plastics like PE, PP are not compatible, thus resulting in poor adhesion resulting in weak interface. [6–8].