**4. Conclusions**

Polymer variability affected the WPC mechanical, physical, and thermal properties. The WPC formulations with higher PP proportions exhibited higher mechanical properties and dimensional stability than those with higher HDPE proportions. Surface chemical and microstructure analysis showed the lack of adhesion between the different phases. The polymers coated the wood fibers without chemical reaction, and PP and HDPE were not miscible.

The polymer mix simulated recycled plastic. Although WPC made with this mix showed lower mechanical properties and dimensional stability than the composites made with one polymer, these composites from these mixes are suitable for several end-uses, sustainable, and have the economic advantage of being made from recycled polymers.
