Assessment of the Impact of Superficial Contamination and Thermo-Oxidative Degradation on the Properties of Post-Consumer Recycled Polypropylene
Single-use plastics are a matter of convenience in everyday life, with the majority allocated to packaging production. However, it comes with a high environmental price as its mass recycling is challenging due to the heterogeneity of composition, contaminations of different kinds, and degradation ca...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-01-01
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| Series: | Materials |
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| Online Access: | https://www.mdpi.com/1996-1944/16/3/1198 |
| _version_ | 1797623940414177280 |
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| author | Laura Prior Mónica S. A. Oliveira Tatiana Zhiltsova |
| author_facet | Laura Prior Mónica S. A. Oliveira Tatiana Zhiltsova |
| author_sort | Laura Prior |
| collection | DOAJ |
| description | Single-use plastics are a matter of convenience in everyday life, with the majority allocated to packaging production. However, it comes with a high environmental price as its mass recycling is challenging due to the heterogeneity of composition, contaminations of different kinds, and degradation caused by service and processing. This study aims to ascertain the impact of removing contaminants from post-consumer recycled polypropylene (rPP) on its degradation and properties by implementing a systematic approach for decontamination by washing. Four lots of recycled plastics with different degrees of contamination were evaluated via Fourier transform infrared, melt flow indexer, and differential scanning calorimetry and tested for tensile strength. Degradation of the rPP was manifested by the deterioration in ductility, resulting in 14.58% elongation at break (unwashed rPP) compared with 191.41% (virgin PP)) and a significant reduction in oxidation induction time. In the unwashed rPP sample, a wave intensity peak at 1730 cm<sup>−1</sup>, assigned to the saturated C = 0 stretch of the carbonyl functional group, was detected. This peak was gradually disappearing with an increase in the cleaning efficiency of rPP, highlighting the role of contaminants as degradation catalysts. The cold-washing method showed similar processing and mechanical performance improvement results compared with the other washing methods, while being more environmentally friendly and energy efficient. |
| first_indexed | 2024-03-11T09:35:54Z |
| format | Article |
| id | doaj.art-c693b2a87e9c48939fbf6f606efc2a7b |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-11T09:35:54Z |
| publishDate | 2023-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-c693b2a87e9c48939fbf6f606efc2a7b2023-11-16T17:18:33ZengMDPI AGMaterials1996-19442023-01-01163119810.3390/ma16031198Assessment of the Impact of Superficial Contamination and Thermo-Oxidative Degradation on the Properties of Post-Consumer Recycled PolypropyleneLaura Prior0Mónica S. A. Oliveira1Tatiana Zhiltsova2Department of Mechanical Engineering, Centre for Mechanical Technology and Automation (TEMA), University of Aveiro, 3810-193 Aveiro, PortugalDepartment of Mechanical Engineering, Centre for Mechanical Technology and Automation (TEMA), University of Aveiro, 3810-193 Aveiro, PortugalDepartment of Mechanical Engineering, Centre for Mechanical Technology and Automation (TEMA), University of Aveiro, 3810-193 Aveiro, PortugalSingle-use plastics are a matter of convenience in everyday life, with the majority allocated to packaging production. However, it comes with a high environmental price as its mass recycling is challenging due to the heterogeneity of composition, contaminations of different kinds, and degradation caused by service and processing. This study aims to ascertain the impact of removing contaminants from post-consumer recycled polypropylene (rPP) on its degradation and properties by implementing a systematic approach for decontamination by washing. Four lots of recycled plastics with different degrees of contamination were evaluated via Fourier transform infrared, melt flow indexer, and differential scanning calorimetry and tested for tensile strength. Degradation of the rPP was manifested by the deterioration in ductility, resulting in 14.58% elongation at break (unwashed rPP) compared with 191.41% (virgin PP)) and a significant reduction in oxidation induction time. In the unwashed rPP sample, a wave intensity peak at 1730 cm<sup>−1</sup>, assigned to the saturated C = 0 stretch of the carbonyl functional group, was detected. This peak was gradually disappearing with an increase in the cleaning efficiency of rPP, highlighting the role of contaminants as degradation catalysts. The cold-washing method showed similar processing and mechanical performance improvement results compared with the other washing methods, while being more environmentally friendly and energy efficient.https://www.mdpi.com/1996-1944/16/3/1198polymersrecyclingdegradationdecontamination by washingpost-consumermechanical properties |
| spellingShingle | Laura Prior Mónica S. A. Oliveira Tatiana Zhiltsova Assessment of the Impact of Superficial Contamination and Thermo-Oxidative Degradation on the Properties of Post-Consumer Recycled Polypropylene Materials polymers recycling degradation decontamination by washing post-consumer mechanical properties |
| title | Assessment of the Impact of Superficial Contamination and Thermo-Oxidative Degradation on the Properties of Post-Consumer Recycled Polypropylene |
| title_full | Assessment of the Impact of Superficial Contamination and Thermo-Oxidative Degradation on the Properties of Post-Consumer Recycled Polypropylene |
| title_fullStr | Assessment of the Impact of Superficial Contamination and Thermo-Oxidative Degradation on the Properties of Post-Consumer Recycled Polypropylene |
| title_full_unstemmed | Assessment of the Impact of Superficial Contamination and Thermo-Oxidative Degradation on the Properties of Post-Consumer Recycled Polypropylene |
| title_short | Assessment of the Impact of Superficial Contamination and Thermo-Oxidative Degradation on the Properties of Post-Consumer Recycled Polypropylene |
| title_sort | assessment of the impact of superficial contamination and thermo oxidative degradation on the properties of post consumer recycled polypropylene |
| topic | polymers recycling degradation decontamination by washing post-consumer mechanical properties |
| url | https://www.mdpi.com/1996-1944/16/3/1198 |
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