Modification of CaCO3 nanoparticle by styrene-acrylic polymer emulsion spraying and its application in polypropylene material

A novel CaCO 3 nanoparticle modification method by a styrene-acrylic polymer emulsion (SAPE) was introduced. The self-made SAPE was sprayed into the nano-CaCO 3 slurry system, and SAPE chains were encapsulated onto the CaCO 3 nanoparticle surface. The modified CaCO 3 nanoparticle mechanism was discussed. Fourier transform infrared spectroscopy confirmed that the SAPE chain was anchored on the nano-CaCO 3 surface by the reaction of the SAPE carboxyl group with the hydroxyl group on the CaCO 3 . The effect of acrylic acid (AA) amount on the activation degree and oil absorption of CaCO 3 /SAPE composite nanoparticles was investigated. The amount of AA was 2%, and the activation degree and oil absorption of the product were optimal. The estimated grafting efficiency of the CaCO 3 /SAPE composite nanoparticles was 90.5% when the amount of acrylamide (AAM) was 1.5%. Scanning electron microscopy showed that the CaCO 3 nanoparticles could be dispersed uniformly in polypropylene (PP) film and formed a closed integration by SAPE-modified CaCO 3 . The styrene-acrylic polymer chains that were grafted on the CaCO 3 nanoparticle surface could improve the compatibility between the CaCO 3 nanoparticles and PP matrix. The PP composite film with modified CaCO 3 nanoparticles had a higher tensile strength than that of pure CaCO 3 nanoparticles, which can improve the mechanical properties of the PP material. • Surface modification of CaCO 3 nanoparticles was performed by a unique process. • The modified CaCO 3 nanoparticle mechanism was elaborated. • The PP with CaCO 3 /SAPE has a higher tensile strength than that of pure CaCO 3 .