Rheology and mechanical properties of recycled PP
Björkqvist, Isabella (2023)
Björkqvist, Isabella
2023
Master's Programme in Materials Science and Engineering
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Hyväksymispäivämäärä
2023-05-04
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202303283249
https://urn.fi/URN:NBN:fi:tuni-202303283249
Tiivistelmä
This thesis is for double degree program between Tampere University of Finland and Universidad Politécnica de Madrid, Spain, commissioned by VTT Technical Research Centre of Finland Ltd. It is related to the EU-funded REVOLUTION project, in which Circular Economy approach is applied to decrease carbon footprint and increase both efficiency and range capability of electric vehicles (EV), utilizing innovative modelling in addition to advanced process control tools. This can be done by increasing plastic parts’ recycled content, implementing lightweight solutions as well as by identifying cost effective ways for further mass production. Environmental and Societal Assessment of the project is conducted within the scope of the project.
With an intention to have over 50 % recycled plastic in automotive parts, it is clear that some adjustment is needed, as recycled plastics rarely have properties demanded in technical applications. The scope of this thesis was thus to study rheological and mechanical properties of recycled polypropylene (PP) together with blends with impact modifiers, blend with only waste feedstock material and compound with minor additivation. Based on this study is obtained valuable information from suitability of recycled polypropylene for final technical application, which has specific rheology requirements and mechanical property demands for high stiffness and high impact strength.
Methods for the studies were rotational rheometer, dynamical mechanical analysis, Fourier transform infrared spectrometry, differential scanning calorimetry (DSC), thermogravimetric analysis combined with DSC, inline rheometer, tensile tests as well as impact tests. The intention of the spectrometry and thermal analysis was in obtaining also some molecular level information to support the results obtained from the rheometers and mechanical tests.
Results were consistent and reliable, although indication of waste feedstock variety was observed. From the results can be concluded, that in recycled polypropylene lies great possibilities for usage in technical applications. In addition, with 51 % recycled polypropylene content can be achieved even better impact strength than virgin polypropylene has. However, when the target is to achieve both high stiffness and high impact strength, a compromise must be made in the amount of the impact modifiers.
With an intention to have over 50 % recycled plastic in automotive parts, it is clear that some adjustment is needed, as recycled plastics rarely have properties demanded in technical applications. The scope of this thesis was thus to study rheological and mechanical properties of recycled polypropylene (PP) together with blends with impact modifiers, blend with only waste feedstock material and compound with minor additivation. Based on this study is obtained valuable information from suitability of recycled polypropylene for final technical application, which has specific rheology requirements and mechanical property demands for high stiffness and high impact strength.
Methods for the studies were rotational rheometer, dynamical mechanical analysis, Fourier transform infrared spectrometry, differential scanning calorimetry (DSC), thermogravimetric analysis combined with DSC, inline rheometer, tensile tests as well as impact tests. The intention of the spectrometry and thermal analysis was in obtaining also some molecular level information to support the results obtained from the rheometers and mechanical tests.
Results were consistent and reliable, although indication of waste feedstock variety was observed. From the results can be concluded, that in recycled polypropylene lies great possibilities for usage in technical applications. In addition, with 51 % recycled polypropylene content can be achieved even better impact strength than virgin polypropylene has. However, when the target is to achieve both high stiffness and high impact strength, a compromise must be made in the amount of the impact modifiers.