Improvement of toughness properties of polypropylene/wollastonite composites using an interface modifier

The effects of type of processing of polypropylene (PP)/wollastonite composites on mechanical properties and dispersion state were investigated. The concentration in weight of the filler in the compounds was of 2.5%, 5%, and 10%, respectively. Stearic acid was used as an interface modifier for the PP-wollastonite system. Wollastonite was also modified with stearic acid. The infrared spectra did not show any chemical changes between unmodified and modified wollastonites. The interactions between wollastonite and stearic acid were mainly physical. The compounds with interface modifier (stearic acid) showed the higher values in impact strength and elongation at break, as well as the best dispersion state. Qualitative chemical analysis on scanning electronic microscopy detected the presence of the acid stearic in the interface. POLYM. COMPOS., 35:1184-1192, 2014. (c) 2013 Society of Plastics Engineers