Open Access

ARTICLE

Effect of Thermal Ageing on the Thermal and Mechanical Properties of Polypropylene and Polypropylene Micro-Composites

by Rachid Bouregba^1,2, Bel Abbes Bachir Bouiadjra^2,*, Mohamed Mokhtar Bouziane³, Mohamed Amine Bellali², Mokadem Salem²

1 Mechanical Engineering Department, Faculty of Science and Technology, Mustapha Stambouli University of Mascara, Mascara, 29000, Algeria
2 LMPM, Mechanical Engineering Department, University of Sidi Bel Abbes, Sidi Bel Abbes, 22000, Algeria
3 Department of Mechanical Engineering, University of Saida, Saida, 20015, Algeria

* Corresponding Authors: Bel Abbes Bachir Bouiadjra. Email: ,

Journal of Polymer Materials 2024, 41(3), 143-158. https://doi.org/10.32604/jpm.2024.056385

Received 22 July 2024; Accepted 13 September 2024; Issue published 30 September 2024

Abstract

The use of polypropylene composites in various industrial fields has expanded considerably in recent years. A number of researches have been carried out to characterize the performance of polypropylene and its composites. However, the effects of ageing on the long-term behaviour of this thermoplastic are not well understood. The purpose of this study is to analyse the consequences of thermal degradation on the thermal and mechanical properties of three distinct materials: virgin Polypropylene (PP), virgin Polypropylene + talc (PP/talc), and virgin Polypropylene + Carbon Black (PP/CB) micro-composites. Specimens of these materials underwent exposure in an oven at a temperature of 50°C for 7 days. This temperature was chosen because previous research has shown that the PP analyzed completely loses its mechanical properties and would be unusable at 60°C. A comprehensive set of tests and analyses, including Thermo-gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) analysis, Dynamic Mechanical Analysis (DMA), and micro-hardness tests, were conducted both before and after thermal ageing. The obtained results indicate that reinforcing polypropylene with mineral particles generally enhances its thermal and mechanical properties. After ageing, the degradation temperature of PP increases by 3% when 4% talc is added, whereas this increase is of the order of 0.2% when 4% carbon black is added. These particles mitigate the adverse effects of thermal ageing on various properties, with the exception of micro-hardness, where higher values were observed for pure polypropylene after thermal ageing. The results show that the addition of talc or carbon black particles improves polypropylene’s thermal stability, crystallinity and mechanical properties. In addition, this addition reduces the negative effects of thermal ageing on the mechanical and thermal properties of PP. The drop in storage modulus after ageing, ageing is of the order of 14% for pure polypropylene, 11% for PP/CB composite and 8% for PP/talc composite.

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