Organic modification of precipitated calcium carbonate nanoparticles as filler in LLDPE/CNR blends with the presence of coupling agents: impact strength, thermal, and morphology
Ahmad Hafizullah Ritonga, Novesar Jamarun, Syukri Arief, Hermansyah Aziz, Denny Akbar Tanjung, Boy Isfa, Vivi Sisca, Hendri Faisal
Abstract
This study reports that Precipitated Calcium Carbonate (PCC) nanoparticles from limestone can be modified with oleic acid (OA), which was applied to LLDPE/CNR blends in the presence of the LLDPE-g-OA coupling agent. This study investigates PCC characteristics from limestone that has been modified with OA and its implications of increasing impact strength, thermal properties, and morphology changes in LLDPE/LLDPE-g-OA/CNR/O-PCC composites. Organo-PCC (O-PCC) was prepared by mixing the PCC with OA in n-hexane solvent. The polymer composites were made by mixing LLDPE, LLDPE-g-OA, and CNR simultaneously in an internal mixer at 160 °C with speed rotation of 100 rpm, followed by O-PCC. The characterization results of O-PCC obtained CaO compounds of 97.9%, crystallinity degree of 61.6%, crystals size of 48.6 nm, and scalenohedral-shaped crystals. The results of the impact strength test on LLDPE/LLDPE-g-OA/CNR/O-PCC composites with an O-PCC concentration of 5 wt% showed an increase of 21.5% compared to no fillers. The presence of O-PCC resulted in the thermal properties of polymer composites with a melting point of 125.5 °C and a decomposition temperature of 468.7 °C. The morphology did not result in significant differences in the surface structure after adding O-PCC nanoparticles.