Produção Nacional
Revisado por pares
Enhancement of the thermooxidative degradability of polystyrene by chemical modification
2004; Elsevier BV; Volume: 86; Issue: 3 Linguagem: Inglês
10.1016/j.polymdegradstab.2004.05.022
ISSN1873-2321
AutoresGabriela Botelho, Arlete Queirós, A. V. Machado, Paulo César Frangiosa, José Ferreira,
Tópico(s)Polymer crystallization and properties
ResumoA comparative study was conducted into the thermooxidative degradation of polystyrene (PS) and polystyrene modified with different percentages (5, 10 and 15) of –CH2(CO)CH2CH2– units (MPS). The influence of the chemical modification on the thermooxidative degradation was assessed by oxygen uptake, FTIR and UV–vis spectroscopy, DSC and viscometry. The oxidation rate, yellowing and formation of oxidation products were accelerated in MPS. The Tg values for undegraded PS and MPS were very similar, suggesting that the mechanical properties are little affected by the modification. The drastic decrease in Tg observed for degraded MPS was related with extensive chain cleavage. This was confirmed by the more pronounced decrease of the intrinsic viscosity of degraded MPS. These results clearly indicated that the thermooxidative degradability of polystyrene could be enhanced after the insertion of units containing carbonyl groups within the polystyrene chain.
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