abstract
- © 2020 by the authors.This research focuses on investigating how physical and mechanical properties of polypropylene (PP) recycled material are modified when ultrasonic micro injection molding (UMIM)technology is used to produce material specimens. Experimental characterization by differentialscanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR)spectra, and rheology tests show that the fabricated PP samples were able to withstand up to fivetimes recycled processing before some signs of mechanical and physical properties degradation areobserved. Surprisingly, uniaxial extension tests show an increase of 3.07%, 10.97% and 27.33% forYoung's modulus, yield stress and ultimate stress values, respectively, and a slight reduction of 1.29%for the samples elongation at break when compared to the experimental data collected from virginmaterial samples. The improvement of these mechanical properties in the recycled samples suggeststhat ultrasonic microinjection produces a mechano-chemical material change.