Study on the influential effect of different CaCO3 particle sizes on the internal pore structure of starch/fiber foaming composite materials

Starch/fiber foaming material is an ideal alternative to non-degradable cushioned packaging products. There still needs to be an improvement in the performance of such materials, which affects their promotion and application. The pore structure significantly impacts the performance of starch/fiber foam composite materials, so adjusting the internal pore structure of foam materials is also an important method to improve the performance of foam materials. In this study, the CaCO3 with particle sizes of 50 pm,5 pm, 500 nm, and 50 nm were separately mixed into the slurry as nucleating agents and composite materials were prepared through a hot pressing process to control the pore structure by adding nucleating agents of different particle sizes. Observing through Scanning Electron Microscope(SEM), the internal pore size of the composite material with 50 pm particle size CaCO3 is about 800 pm. The composite material made of CaCO3 with a particle size of 50 nm has a pore size of only 333 pm. It has decreased by 58% compared to the composite material with 800 pm CaCO3. The results indicate that as the size of CaCO3 particles decreases, the composite material exhibits more uniform and dense vesicles, and its water resistance, thermal stability, and corrosion resistance have also improved to a certain extent.The material made by adding the smallest particle size CaCO3 has a minimum degradation rate of about 10.5% in 30 days, and the buffering efficiency is highest when the stress is greater than 2 MPa, reaching about 22%.