Biodegradable PBAT/PLA/CaCO 3 Blowing Films with Enhanced Mechanical and Barrier Properties: Investigation of Size and Content of CaCO 3 Particles

Abstract Biodegradable poly(butylene adipate‐co‐terephthalate)/poly(lactic acid)/calcium carbonate (PBAT/PLA/CaCO 3 ) blend films with variable compositions are prepared using one‐step melt‐blending and a following film‐blowing. The effects of CaCO 3 content and particle size on the physicochemical properties of the films are investigated. The rheology results demonstrate that the storage modulus and complex viscosity are increased with the increasing CaCO 3 content. The tensile performance and tear resistance including both the machine direction (MD) and transverse direction (TD) are also improved by adding CaCO 3 . Especially, P7/P3/C 3000 30 achieves the highest tensile and tearing strength in MD of 31 ± 2.5 MPa and 99 ± 4.0 N mm −1 , respectively. Compared with unfilled PBAT/PLA films, the water vapor transmission greatly declines from 621 to 287 g m −2 24 h and the oxygen transmission values are also reduced from 1400 to 1010 cm 3 m −2 d Pa after the incorporation of CaCO 3 particles. A slight decrease in thermal stability is detected in PBAT/PLA/CaCO 3 , but overall, the decomposition temperature is much higher than the processing and service temperature. Therefore, the biodegradable PBAT/PLA films with low‐cost CaCO 3 fillers demonstrate excellent mechanical and oxygen and moisture barrier performance, which show great potentials in food‐packaging and mulch film in the agriculture field.