Recently, natural-fiber-reinforced polymers have attracted the attention of
researchers because of their advantages over established materials. Plant fibers
are naturally available and biodegradable which caused lesser ecological impact
than mineral fillers. Natural fibers also contributed to their low cost, low-density,
lower abrasive nature, higher specific strength, and higher modulus of elasticity
[1,2]. Despite the mentioned above advantages, it is difficult to achieve strong
interfacial adhesion between the hydrophilic surface of the wood and the
hydrophobic thermoplastic polymers [3]. Because wood plastic composites (WPCs)
are true hybrid materials, they have strength and stiffness properties that are
somewhere between wood and plastic [2,3]. The mechanical properties of reinforced
polymers can be improved by optimizing the interphase between the matrix and
the filler by coupling agents [1, 4-7] and also the properties of the filler, by taking
into consideration the amount used in the blend. To improve adhesion between
matrix and filler, the surface of material can be modified by chemical treatments or
by use of coupling agents.