Toughening polypropylene by tiny amounts of fillers

Purpose The purpose of this paper is to prepare new modified polypropylene (PP) with phenolic microspheres (PFMs). Furthermore, the crystallinity and mechanical properties of PP modified by fillers (silicon dioxide [SiO2] and light calcium carbonate [CaCO3], respectively) have also been investigated and compared. Design/methodology/approach For effective toughening, three different fillers were added into the PP matrix. PP composites were prepared through melt blending with double-screw extruder and injection moulding machine. Findings It was found that with the addition of 3 Wt.% PFM, the impact strength was maximum in all PP composites and increased by 1.4 times compared to pure PP. Scanning electron microscopy (SEM) and polarised optical microscopy (POM) analysis confirmed that 3 Wt.% PFM, 3 Wt.% SiO2 and 2 Wt.% CaCO3 were optimal to add in PP and PFM to give the best compatibility with PP. Research limitations/implications PFM particles not only are tougher and less brittle and can offer other advantages such as enhanced machinability, but also are important organic materials and have a good compatibility with polymer for reinforcing polymer properties. Practical implications The method developed provided a simple and practical solution to improving the toughness of PP. Social implications There will be thermoplastic plastics with higher toughness in domestic, packaging and automotive applications, particularly at lower temperatures. Originality/value The PP modified by tiny amounts of fillers in this work had high toughness, which can be applied as an efficient material widely used in domestic, packaging and automotive applications.