Organically modified mesoporous silica as a performance additive in tubular quenched polypropylene films

Abstract

Mesoporous silica nanoparticles were synthesized by base-catalyzed hydrolysis of tetraethyl orthosilicate in the water-acetone medium. For surface modification of mesoporous silica, commercially available silane, 3-(trimethoxysilyl)propyl methacrylate was reacted with mono-thioglycerol via 2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl (TEMPO) aided thiol-ene reaction, and the obtained silane was incorporated on the surface of neat mesoporous silica to graft extended alkyl chains terminating in hydroxyl groups. The prepared MSNs were characterized by thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption-desorption analysis, scanning electron microscopy, and dynamic light scattering. These MSNs were compared to conventionally used commercial silica as an additive in tubular quenched polypropylene films (TQPP) for their anti-blocking, thermal, mechanical, optical, and barrier properties. Organic modification of MSNs decreased the blocking force in TQPP films. The mechanical properties including % elongation and tensile strength increased for TQPP films with mesoporous silica, while it decreased for films containing commercial silica. Both modified and unmodified MSNs decreased haze and enhanced gloss in TQPP films, showing improved optical properties as compared to commercial silica particles. In TQPP film with modified MSNs, a reduced value of the water contact angle was obtained, indicating better wettability of the surface of the TQPP film.