The Influence of Nano-CaCO 3 on the Mechanical and Dynamic Thermo-Mechanical Properties of Core–Shell Structured Wood Plastic Composites.

Using bamboo residue and high-density polyethylene (HDPE) as the main raw materials, core–shell structured wood plastic composites (WPCs) with nano-CaCO₃ filling shell were prepared by coextruded technology. The effect of nano-CaCO₃ contents on the flexural properties, impact strength and dynamic thermo-mechanical properties of the core–shell structured WPCs were investigated. And the value of core–shell interface interaction parameter was calculated by dynamic thermodynamic parameters. The results showed that the flexural strength increased by 48.1% and 40.3% when it was loaded with 10%–15% nano-CaCO₃, compared to the HDPE shell composites, respectively. While nano-CaCO₃-filled HDPE shell had lower impact strength in comparison with HDPE shell, the field emission scanning electron microscope revealed proper interfacial adhesion between the core and shell layers. The storage modulus of core–shell structured WPCs increased as nano-CaCO₃ contents increased, but the values were lower than that of the HDPE shell. Addition of nano-CaCO₃ caused an increase in the glass transition temperature (T_g) of the core–shell structured WPCs, loss factor (tanδ) of the core–shell structured WPCs decreased. The value of the core–shell interface interaction parameter of the core–shell structured WPCs increased significantly after the nano-CaCO₃ loading reached 15%, which was consistent with the bending test results. These findings demonstrate that the core–shell structured WPCs have excellent properties filling with nano-CaCO₃ in the shell layer, and bamboo residue is added to the core layer. [ABSTRACT FROM AUTHOR]