Induction time and later degradation of outdoor exposed polypropylene cast film studied by differential scanning calorimetry
| Autor: | Febo Severini, Salvatore Ipsale, Raffaele Gallo, Natalino Del Fanti |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Polypropylene
Polymers and Plastics Induction period Enthalpy of fusion Enthalpy Mineralogy Condensed Matter Physics chemistry.chemical_compound Differential scanning calorimetry chemistry Mechanics of Materials Materials Chemistry Degradation (geology) Composite material Thin film Chemical decomposition |
| Zdroj: | Polymer Degradation and Stability. 55:199-207 |
| ISSN: | 0141-3910 |
| DOI: | 10.1016/s0141-3910(96)00134-6 |
| Popis: | The outdoor ageing of a polypropylene (PP) cast film, free of stabilisers and exposed directly or covered by glass, has been studied mainly by means of differential scanning calorimetry (DSC) measurements. Time dependences of the enthalpies and the peak temperatures of all the samples are not straight lines. The recurrence of high and low values of these quantities has been related to the organization of the system from the starting polypropylene matrix and from the occurring oxygenated fragments. In fact, meaningful changes in these thermal parameters take place even during the first 800 exposure hours, in the absence of oxidation. This shows that the oxidation reaction of the system is preceded by considerable morphological changes in the material. |
| Databáze: | OpenAIRE |
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