Gas-solid fluidization modification of calcium carbonate for high-performance poly (butylene adipate-co-terephthalate) (PBAT) composites

Modifying biodegradable poly (butylene adipate-co-terephthalate) (PBAT) plastic with inorganic fillers is critical for improving its overall performance, lowering the costs, and expanding its application scope. The chemical modification method for the inorganic filler determines the application performance of PBAT composites. In this work, gas—solid fluidization method was developed as a simple, efficient, and scalable strategy for chemically modifying CaCO(3) filler. The modified CaCO(3) filler was mixed with PBAT and melt extruded to prepare biodegradable PBAT/CaCO(3) composites. The characterization results show that gas—solid fluidization method combines the traditional wet modification method’s excellent modification effect with the scalability of the traditional dry modification method. The effects of modification methods and amount of CaCO(3) filling on the crystallinity, mechanical, and rheological properties of PBAT/CaCO(3) composites were compared. The results demonstrated that PBAT/CaCO(3) composites containing 30% gas—solid fluidization modified CaCO(3) could still maintain excellent overall performance. As a result, this work provides a simple, efficient, and scalable method for chemically modifying inorganic fillers and preparing biodegradable composites.