Optimization of composites based on PP/elastomer blends and short PET fibers

Abstract The physical and mechanical properties of ternary composites based on isotactic polypropylene (iPP) and ethylene—octene copolymer blends reinforced with poly(ethylene terephthalate) (PET) fibers have been studied. In order to evaluate the effect of the matrix composition and fiber content on the final properties of the composite, an experimental design based on a Doehlert Uniform Net has been employed. The results show that PET fibers behave as a reinforcing agent for PP/ethylene—octene copolymer blends, this effect being more evident at high copolymer percentages in the blend. It is important to notice that the analyzed mechanical properties are more dependent on matrix composition than on fiber percentage. So, as PP content is increased, the blend becomes more rigid and stable, and a noticeable increase in tensile and flexural modulus and strength are observed. Moreover, dynamic mechanical measurements provide a further confirmation of the reinforcing effect of these fibers. A displacement of t...