Photodegradation and Photostabilization of Poly(3-Hydroxybutyrate)
| Autor: | Renate Maria Ramos Wellen, Eduardo Luís Canedo, Marcelo Silveira Rabello, Guilhermino José Macêdo Fechine |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Materials Research, Vol 19, Iss 4, Pp 759-764 (2016) |
| Druh dokumentu: | article |
| ISSN: | 1516-1439 1980-5373 |
| DOI: | 10.1590/1980-5373-MR-2015-0666 |
| Popis: | The present work is concerned with the photodegradation and photostabilization of poly(3-hydroxybutyrate) (PHB) biopolymer. Two commercial grades of PHB were investigated, containing of 4.0% and 6.2% of hydroxyvalerate (HV) comonomer, named PHB1 and PHB2, respectively. Injection moulded specimens were exposed to ultraviolet radiation (UV-A) in the laboratory for periods of up to 12 weeks and then characterized by tensile testing, surface appearance, size exclusion chromatography (SEC), and scanning electron microscopy (SEM). The exposure to UV radiation caused great damaged on the surface color, reduction of molecular size and mechanical properties. The effects were more pronounced on PHB2, probably due a lighter surface color and less packed macromolecular structure which facilitates the transmission of light throughout the samples. Specimens of PHB1 were also injected with the addition of a UV absorber and antioxidant, resulting in a higher UV stability of PHB, as shown by a low reduction in molar mass and better mechanical properties. |
| Databáze: | Directory of Open Access Journals |
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