Table 3.
Co-occurrence and total link strength of the most common keywords.
| # | Selected Keywords | Cluster Number | Occurrences | Total link strength | Average Publication Year |
|---|---|---|---|---|---|
| 1 | Circular economy | 3 | 135 | 134 | 2018 |
| 2 | Recycling | 2 | 42 | 67 | 2018 |
| 3 | Waste plastic | 2 | 6 | 27 | 2019 |
| 4 | Polymers | 2 | 5 | 25 | 2019 |
| 5 | Upcycle | 2 | 5 | 25 | 2019 |
| 6 | Plastic waste | 4 | 12 | 24 | 2019 |
| 7 | Additive manufacturing | 2 | 6 | 21 | 2019 |
| 8 | Plastic | 1 | 10 | 20 | 2018 |
| 9 | Plastics | 4 | 12 | 19 | 2017 |
| 10 | Waste | 1 | 10 | 18 | 2017 |
| 11 | Plastic recycling | 4 | 9 | 17 | 2019 |
| 12 | Sustainability | 1 | 14 | 16 | 2018 |
| 13 | Life cycle assessment | 3 | 10 | 14 | 2018 |
| 14 | Waste management | 3 | 11 | 14 | 2018 |
| 15 | Bioplastics | 1 | 8 | 13 | 2019 |
| 16 | Packaging | 1 | 6 | 13 | 2019 |
| 17 | 3d printing | 2 | 5 | 12 | 2019 |
| 18 | Pyrolysis | 4 | 8 | 11 | 2019 |
| 19 | Recovery | 4 | 5 | 8 | 2017 |
| 20 | Contamination | 3 | 5 | 7 | 2019 |
| 21 | LCA | 1 | 5 | 7 | 2018 |
| 22 | Municipal solid waste | 3 | 6 | 6 | 2017 |