Photodegradation of a polypropylene filled with lanthanide complexes

Abstract

SbstractThis research aims at studying the photodegradation of a polypropylene formulation filled with lanthanide complexes. These complexes can be used as tracers for the identification of polymer materials in order to facilitate an high speed automatic sorting of plastic wastes for an economically efficient recycling. By paying attention to the evolution of carbonyl absorption bands in FTIR spectra, it is observed that the addition of lanthanide complexes into our formulation improves UV stability of polypropylene by reducing the extent of photo-degradation. Furthermore, TG analyses show that the traced blends can maintain better thermal properties, after irradiation. A significant increase of the crystallinity degree and a decrease of the melting temperature are more pronounced for the unfilled UV-irradiated PP. This might result from chemi-crystallization that can occur when chain entanglements are broken as a result of chain scissions. From SEM analyses, it is observed that the severity of surface cracks induced by photo degradation is reduced for filled PP. The mechanical tests are in agreement with this result and show a fundamental change in the behavior of the as-exposed blends from a ductile to a brittle material.

Enhanced aging resistance of poly(ε-caprolactone)/brewers’ spent grain composites

“…Observed changes confirmed that the UV degradation of poly(ε-caprolactone) occurs mainly in the amorphous phase, affecting crystallization behavior. The UV-light exposure usually led to polymeric matrix chain--scission effects, which provided higher mobility of PCL chains during solidification and the ability to create crystalline domains [37]. The increase in T c was noted from the initial 24.8 to 26.8°C.…”

Boosting photocurrent of anodized Nb2O5 by synergetic post-synthesis electrochemical treatment

“…It is observed that at low potentials, below 0.2 V, although there is a high photoactivity, the recombination rate is also appreciable, and this decreases as the potential increases. 33 However, it is necessary to consider both photodegradation and electrodegradation by using too high potentials under lighting. Thus, 1.2 V was chosen as the working potential, which presented a good balance between the amount of photocurrent and the material's durability.…”

Environmental effects of ozone depletion and its interactions with climate change: Progress report, 2016

“…Outdoor service life of common plastics such as polyethylene 363 , 364 and polypropylene 365 is determined primarily by solar UV radiation dose and sample temperature. Relationships that estimate the increased weathering of these at higher ambient temperatures are commonly available.…”