The Influence of Nano-CaCO3 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 (tan delta) 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.

Automated summary

In this study, core-shell structured wood plastic composites (WPCs) with nano-CaCO3 filling shell were prepared using bamboo residue and high-density polyethylene (HDPE) as the main raw materials through coextruded technology. The effects of nano-CaCO3 contents on the flexural properties, impact strength, and dynamic thermo-mechanical properties of the WPCs were investigated. The results showed that the addition of nano-CaCO3 significantly improved the flexural strength of the WPCs but reduced the impact strength. Moreover, the storage modulus increased with the increasing nano-CaCO3 contents, and the glass transition temperature (T-g) increased while the loss factor (tan delta) decreased.