Preparation of intercalating halloysite by in situ synthesized polymethyl methacrylate and its effects on the crystallization behaviors and mechanical properties of polylactic acid composites

Abstract Polylactic acid/halloysites (PLA/HNTs) composites with different nanotube contents were prepared by solution blending. Using unmodified HNTs and polymethyl methacrylate intercalated halloysites (PMMA‐HNTs), their structures and properties were comparatively investigated. It is found that the glass transition temperature ( T _g ) of the composites is lower than that of pure PLA. In addition, both HNTs and PMMA‐HNTs promoted the crystallization of PLA. However, due to the good dispersion of PMMA‐HNTs in the matrix, the crystallinity of PMMA‐HNTs‐modified PLA is higher than that of HNTs‐modified PLA loaded with the same nanoparticles. The study on the mechanical properties of PMMA‐HNTs and HNTs‐modified PLA composites suggested that when the content of PMMA‐HNTs was not higher than 4 wt%, it could simultaneously improve the elongation at break and tensile strength. Thermal stability studies showed that the T _5% and T _max of the two composites did not improve significantly, but the amount of carbon residues increased. This study provides a new strategy for modifying HNTs and preparing PLA composites with good comprehensive properties.