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.