High-reactive silica nanosheets as compatibilizers for immiscible PLLA/PBAT polymer blends

While nanoparticles were considered to be the most promising compatibilizers for immiscible polymer blends, high-efficient nanoparticle-based compatibilizers were still under development. Herein, a high-reactive silica nanosheet (HRN) compatibilizer with excellent compatibilization effect was synthesized and its compatibilization effect was investigated. The HRN compatibilizer was fabricated by skillfully melt-blending amino functionalized silica hollow spheres (AHS) and the poly(styrene-co-glycidyl methacrylate) (PSGMA) with average ten reactive epoxy groups per chain. During the mixing, the AHS were crushed to nanosheets upon the strong shearing and simultaneously grafted PSGMA chains on nanosheets via the reaction of epoxy and amino groups. The PSGMA with high epoxy groups content endowed the HRN with high reactivity. To demonstrate the compatibilization efficiency of our high-reactive compatibilizer, different amounts of HRN were incorporated into the immiscible polylactic (l-acid)/polybutylene adipate terephthalate (PLLA/PBAT) blend, a blend system widely applied in packing and agricultural films, to investigate and compare the changes in morphologies and mechanical properties. Only 3 wt% addition of HRN compatibilizer could significantly decrease the droplets size and dramatically improve the tensile strength and elongation at break of the blend by 1.4 and 23 times. The present work provided a new idea for the development of nanoparticle-based compatibilizer with high compatibilization efficiency.