Surface modification of calcium carbonate by thiol-ene click reaction and its effect on the performance of PVC composite

Disposable PVC gloves are cost effective, but their mechanical properties can be compromised at extremely high concentrations of plasticizers. The tensile properties of PVC gloves can be improved by incorporating modified fillers into the PVC matrix. In this research, calcium carbonate (CaCO3) was functionalized with gamma-methacryloxy propyl trimethoxyl silane (KH-570) and then further modified through a click reaction with n-Octadecyl mercaptan. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy have confirmed that n-Octadecyl mercaptan-modified KH-570 was successfully grafted onto the surface of CaCO3. Composite films were manufactured by blending either pristine CaCO3 or modified CaCO3 with PVC resin paste and their tensile properties, light transmission, moisture permeability, and solvent resistance were evaluated. Compared with CaCO3/PVC and KH-570-modified CaCO3/PVC composite films, n-Octadecyl mercaptan-modified CaCO3/PVC composite films showed higher light transmittance, lower moisture permeability, and higher tensile properties. Dynamic mechanical analysis revealed that these films had low glass transition temperatures, thus broadening their applicability to low-temperature conditions.