Enhanced toughness and low temperature mechanical properties of PVC composites with PMMA grafted attapulgite via interface engineering

Brittleness and low fracture toughness severely limit the performance of rigid polyvinyl chloride (PVC) composites in extreme environments. To address this, we developed a modified filler (mATP@PMMA) by first modifying attapulgite (ATP) with a titanate coupling agent (TCA), which then served as a molecular bridge to graft polymethyl methacrylate (PMMA) onto the ATP surface via emulsion polymerization. This design promotes uniform dispersion and strong interfacial adhesion, effectively dissipating energy and thereby enhancing mechanical properties. Experimental results show that adding only 3 phr of mATP@PMMA significantly improves the processability, thermal stability, and dynamic mechanical performance of the PVC composite. At room temperature, tensile strength, flexural strength, and impact strength increase by 26.8%, 32.5%, and 23.1%, respectively. Even at −20 °C, the composite maintained high strength and exhibited considerable resilience, with SEM fractography clearly revealing effective interfacial interactions. While the impact strength of PVC drops by 48.4% at low temperature, the composite with PVC/mATP@PMMA shows only a 14.8% reduction. As a highly efficient performance additive, mATP@PMMA demonstrates considerable potential for manufacturing high performance composites.