Chemiluminescence of isotactic polypropylene induced by photo‐oxidative degradation and natural weathering

Abstract

The analysis of the chemiluminescence (CL) kinetic parameters (induction time, oxidation rate, and activation energy) after the UV irradiation and outdoor exposure of isotactic polypropylene (i-PP) films have been studied. The initial CL emission intensity increased with increasing photodegradation time of i-PP films. On photodegradation, the activation energies were found to decrease linearly with time of UV-irradiation and outdoor exposure.The slopes of these linear dependences were used to indicate the degree of photodegradation of the polymer and also for the characterization of the stabilizing effect of the additive.

Fluorescence confocal microscopy as effective testing method of polypropylene fibers and single polymer composites

“…The general mechanism of PP luminescence is related to the presence of oxygen reacting with the polypropylene [19] and the oxidation can be promoted by presence of ozone, UV radiation, humidity and mechanical stress. The luminescence of PP takes a form of chemiluminescence, plasma-induced luminescence and UV excited fluorescence or phosphorescence [20,21]. Dissimilarly to our observations polypropylene usually exhibits luminescence in violet or ultraviolet region [22,23].…”

Low-κ′ dielectric properties of UV-treated bi-axially oriented polypropylene films

“…It is known that the degradation reactions in semicrystalline polymers proceed predominantly in the amorphous regions. Photodegradation basically depends on oxygen kinetics and permeability through the material [30]. Photodegradation may be affected by polymer reactivity, the presence of chromophoric impurities, additives [31] and the relative pressure of oxygen [32].…”

Effect of accelerated aging on the structure and properties of monolayer and multilayer packaging films

“…7 As generally accepted in the related literature, degradation reactions of semicrystalline polymers proceed predominantly in the amorphous regions; nevertheless, physical factors, such as the size, arrangement, and distribution of the crystalline regions, play an important role in the degradation process as well. The photodegradation kinetics in polymer systems basically depend on the oxygen permeability through the material.…”

“…The greatest damage to polymers exposed to natural conditions is caused by the UV portion of sunlight, even though this portion represents up to 10% (depending on the atmospheric conditions and latitude) of the total energy reaching the earth from the sun, with about 50% of it being visible light and about 40% IR light 7…”