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| Titel: |
Miscibility of PET/PC Blends Induced by Cobalt Complexes |
| Auteur: |
Mendes, Luis C. Giornes, Alexey M. Dias, Marcos L. Cordeiro, Alexandre F. Benzi, Marcia R. |
| Verschenen in: |
International journal of polymeric materials |
| Paginering: | Jaargang 56 (2007) nr. 3 pagina's 257-272 |
| Jaar: |
2007-03-01 |
| Inhoud: |
Amorphous miscible PET/PC copolymers were prepared by blending the two constituent blend homopolymers at 50/50 wt% proportion in presence of cobalt acetylacetonate II and III (0.05 and 0.1 wt%) in the molten state. The reaction products were evaluated by solubility in methylene chloride (CH2Cl2), differential scanning calorimetry (DSC), thermogravimetry (TGA), and Fourier transform infrared spectroscopy (FT-IR). Two fractions were obtained by extracting the blend with CH2Cl2: one soluble, rich in PC, and another one insoluble, rich in PET. The DSC showed a unique glass transition temperature (Tg) (around 100°C) and the absence of melting temperature peak of PET, indicating that an amorphous copolymer was obtained. The Tg value coincides with Fox and Couchman's calculations and indicates the formation of a miscible system. TGA curves of the blends showed thermal degradation between that of the homopolymers. FT-IR showed a decrease of PC carbonyl band at 1773 cm-1, a broadening of PET ester carbonyl band at 1720 cm-1, a decrease of PET degree of order and a new band at 1063 cm-1 attributed to the formation of aromatic-aromatic ester structure in the copolymer. The composition of CH2Cl2 insoluble and soluble phases were determined by FT-IR from calculation using the molar absorptivity of PC p-disubstituted ring band (558 cm-1) and Lambert-Beer's law. The results indicated that exchange reactions took place, predominantly alcoholysis and acidolysis, and were to some extent dependent on the type and amount of cobalt complexes. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 6 van 9 gevonden artikelen
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