Improved properties of poly(butylene adipate‐co‐terephthalate)/calcium carbonate films through silane modification

Abstract One of the most used inorganic fillers is calcium carbonate which quite efficiently enhances the mechanical characteristics while simultaneously lower the cost of thermoplastics, particularly for biodegradable polyester. Virtually, all studies so far have focused on the quest for the filling and modification of nano‐sized calcium carbonates. However, the quantity of nano‐sized CaCO 3 added in the polymer is usually lower than 10%, owing to its high‐surface energy and high‐surface area and makes powder easier to agglomerate. In this work, we prepared poly(butylene adipate‐co‐terephthalate) (PBAT)/calcium carbonate composite films by extrusion‐blown films with up to 40 wt% micro‐sized CaCO 3 content. The influence of particle size (5–12 μm) and modification of the particles (with and without silane coupling agents) on the rheological and mechanical properties was thoroughly investigated. Of all the particle sizes employed in this study, the 5 μm (3000 mesh) particles with 30 wt% content coated with 2 wt% aliphatic silane coupling (CA1) agent was observed to furnish the optimum combination of characteristics. The mechanical properties of P7C3/CA1‐2 film even better than that of neat PBAT film. These results provided a simple approach for PBAT/CaCO 3 films manufacture with low‐cost and simultaneously with sound mechanical properties, which can be good candidate for mulching films and packaging applications.