Structure and Properties of Bisphenol a Polycarbonate Exposed to Ultraviolet

2013 ◽  
Vol 377 ◽  
pp. 255-260
Author(s):  
Yong Ge ◽  
Tao Wang ◽  
Yue Yan ◽  
Lei Li
Keyword(s):  
Bisphenol A ◽  
Light Transmission ◽  
Irradiation Time ◽  
Attenuated Total Reflection ◽  
Chemical Degradation ◽  
Surface Phenomenon ◽  
Exposed Surface ◽  
Structure And Properties ◽  
Bisphenol A Polycarbonate ◽  
Molecular Weights

In this study, the structure and properties of bisphenol A polycarbonate (BPA-PC) after UVB-313 radiation were investigated. When BPA-PC was exposed to ultraviolet (UV), this polymer showed two different degradation mechanisms: photo-Fries rearrangement and photo-oxidation. The interpretation of the observed chemical degradation was based on attenuated total reflection IR (ATR). Gel permeation chromatograph (GPC) measurements indicated that the molecular weights of exposed surface sample were decreased with increasing of irradiation time, but the molecular weights of bulk polymer did not decrease severely. Namely, the degradation of BPA-PC was a surface phenomenon, which only extended about several micrometers into the exposed surface. This also could explain why the mechanical properties of samples showed no change. In addition, photo-induced yellowing of the aged PC was aggravated with the irradiation time prolonging, but no remarkable changes of light transmission have been observed.

scholarly journals Chemical Degradation and Color Changes of Paint Protective Coatings Used in Solar Glass Mirrors

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 476
Author(s):  
Mohamed Guerguer ◽  
Sanae Naamane ◽  
Zineb Edfouf ◽  
Olivier Raccurt ◽  
Hassan Bouaouine
Keyword(s):  
Protective Coatings ◽  
Natural Aging ◽  
Attenuated Total Reflection ◽  
Chemical Degradation ◽  
Complete Analysis ◽  
Color Changes ◽  
Colorimetric Measurements ◽  
Marine Site ◽  
Service Conditions ◽  
Paint Coatings

This paper reports a study of the influence of outdoor natural aging on paint coatings applied to the back of three commercial solar glass mirrors (A1, C2, and D2) under two different exposure environments (marine and desert) in Morocco for a period of about three years. The aging assessment was carried out through colorimetric measurements and FTIR-ATR (Attenuated total reflection-Fourier transform infrared) analyses of the top coat paints. The obtained results demonstrate that the tested coating system had a high resistance at the desert site. Under the desert environment, no obvious changes to the coating occurred after 350 days. However, at the marine site, some color changes were detected, and the coating got yellow and more matte, especially for mirror A1. FTIR-ATR analyses have indicated many modifications in the intensity of many bonds of infrared spectra especially for paint of this mirror type (A1). This chemical degradation is not only due to UV degradation but also related to many factors, such as humidity, salinity, and rainfall. This finding was concluded after the faster degradation observed on samples exposed at the marine site. The present study confirms the need to use different exposure environments for testing the limits of new protective systems for solar glass mirrors rather than using only the real service conditions. Finally, accelerated tests are necessary for understanding the effect of each degrading parameter and their results should be compared to outdoor tests data for a complete analysis of coatings durability.

Model of the selective laser sintering of bisphenol-A polycarbonate

1993 ◽  
Vol 32 (10) ◽  
pp. 2305-2317 ◽  
Author(s):  
J. Christian Nelson ◽  
Samuel Xue ◽  
Joel W. Barlow ◽  
Joseph J. Beaman ◽  
Harris L. Marcus ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Bisphenol A Polycarbonate
Sign in / Sign up

Export Citation Format

Share Document