| Journal: | Materials research |
| Database: | PERIÓDICA |
| System number: | 000312415 |
| ISSN: | 1516-1439 |
| Authors: | Mancini, Sandro Donnini1 Zanin, Maria |
| Institutions: | 1Universidade Federal de Sao Carlos, Departamento de Engenharia de Materiais, Sao Carlos, Sao Paulo. Brasil |
| Year: | 1999 |
| Season: | Ene |
| Volumen: | 2 |
| Number: | 1 |
| Pages: | 33-38 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Experimental |
| English abstract | Bottle grade virgin PET (polyethylene terephthalate) resin was investigated through five consecutive injection molding steps to simulate recycling cycles. Tests were carried out after each recycling to evaluate degradation, crystallinity (by density and Differential Scanning Calorimetry-DSC measurements), hardness, and tensile and flexural properties. Consecutive recycling resulted in cumulative chain breaks caused by the material's contact with degrading agents such as temperature, oxygen, mechanical stresses, light, and water. In the fifth recycling step, for example, the number of carboxylic end groups, an indicator of the extent of chain-break, tripled in comparison to the initial molecule. The smaller chains that were formed fit more easily among the larger ones, thus increasing the percentage of crystalline phase in the structure. These two changes in the polymer's structure explained the recycled products' final properties, i.e., the injected samples became progressively harder and more fragile in each recycling step |
| Disciplines: | Ingeniería, Biología |
| Keyword: | Ingeniería de materiales, Ingeniería mecánica, Ecología, Reciclaje, Cristalinidad, Propiedades mecánicas, Polietileno tereftalato (PET), Degradación |
| Keyword: | Engineering, Biology, Materials engineering, Mechanical engineering, Ecology, Recycling, Crystallinity, Mechanical properties, Polyethylene terephthalate (PET), Degradation |
| Full text: | Texto completo (Ver HTML) |
