Outdoor and accelerated weathering studies of bisphenol A polycarbonate

Abstract

a b s t r a c tThe influence of outdoor weathering on the degradation rate of unstabilized bisphenol A polycarbonate (BPA-PC) films is investigated and compared to the results found for indoor accelerated weathering conditions, using UV and IR spectroscopy. At the same dosage, changes in UV and IR were larger for the accelerated than for the outdoor weathered samples, this could be explained by the lower degradation temperature during outdoor exposures. The difference between outdoor and accelerated weathering is according to the IR measurement larger than according to the UV measurement. This difference is ascribed to difference in wavelength distribution between the spectra of the light emitted in the accelerated test and from the terrestrial sunlight. The larger difference for the IR results than for the UV results suggests a difference in ratio between photo-Fries rearrangements and photo-oxidation reaction between both exposures.

Effect of environmental conditions on the durability of polycarbonate for the protection of cultural heritage sites

“…11 To monitor the oxidation during the tests, the band centered at about 1713 cm -1 , due to the aliphatic chain acids, was measured. 15,22 Light transmission and haze were measured by using a spectrophotometer UV-VIS JASCO model V-650. The haze was measured according to EN 2155-5, with the yellowness index (YI) according to ASTM E313.…”

“…[2][3][4] Photo-degradation is the main cause of the loss of PC's properties. The photo-degradation of this polymer has been widely studied in the literature [5][6][7][8][9][10][11][12][13][14][15] and involves two different mechanisms: photo-Fries reaction and photo-oxidation.…”

Evaluation of recycling of polycarbonate sheets used in ballistic glass packages

“…Figure 10 shows the characteristic spectrum obtained for all the samples. For a pure PC material, absorbance of UV radiation begins only at wavelengths below 300 nm [12][13][14]. However, the virgin PC analyzed here is a commercial product ready to be used in a ballistic package and, therefore, contains UV absorbers.…”

“…The specific UV absorber used is proprietary. Indeed, the selective absorption of UV radiation at wavelengths between 330 and 400 nm is envisaged because this is the region of highest intensity of wavelengths of the solar radiation [13,14]. Figure 11 shows the dynamic mechanical behavior of the virgin PC, and Table 3 lists the values of the storage modulus, E′, at ambient temperature (25 °C) and at 100 °C.…”

Recycled polycarbonate/acrylonitrile–butadiene–styrene reinforced and toughened through chemical compatibilization

“…To recycle these waste plastics more efficiently, researchers have conducted many studies on the aging of these materials under experimental conditions to investigate the degradation mechanism and modification of recycled polycarbonate (R‐PC)–ABS waste with various approaches. Under the comprehensive effects of heat, oxygen, and radiation, the isopropylidene groups in PC are extremely unstable; this leads to the breakage of the molecular chain and a decrease in the molecular weight . Hydroxyl groups are produced during degradation .…”