Portal de Periódicos da CAPES

Photoageing of rigid PVC—IV. Effects of titanium dioxide

1998; Elsevier BV; Volume: 61; Issue: 2 Linguagem: Inglês

10.1016/s0141-3910(97)00132-8

1873-2321

C. Anton‐Prinet, G. Mur, M. Gay, L. Audouin, J. Verdú,

TiO2 Photocatalysis and Solar Cells

The photoageing of unpigmented and TiO2 (5%) pigmented rigid PVC samples has been studied in reactors equipped with different types of fluorescent lamps. The changes in thickness distribution of carbonyl and conjugated polyene concentrations were followed by IR and UV spectrophotometry on microtomed slices (20 μm) and discussed on the basis of kinetic results obtained on thin films (~80 μm) under the same conditions. In the presence of TiO2, the thickness of the degraded layer is divided by about 2 whereas the screen effect is multiplied by 5. From a comparison of photo-oxidation rates with sources of distinct spectra it is hypothesized that the observed penetration of photoageing could be due to a radiation wavelength of ~390 nm, close to the absorption cut-off of TiO2.