Kinetic Study of the Degradation and Stabilisation of Polymers

Abstract

It is theoretically predicted that an isolated narrow resonance in the elastic scattering of electrons by alkali-metal atoms (M) gives rise to a single maximum in the n dependence of the total cross sections of high-Rydberg atoms A** in the highest allowed angular momentum states with M if the resonance width is roughly equal to or larger than the width of a single peak of the electron momentum distribution of the Rydberg states with highest angular momentum, i.e., I = n -1. This can be used to detect the narrow resonance theoretically predicted in e-M elastic scattering at ultra-low energies.

Fragmentation of Chitosan by Acids

“…Polymers containing heteroatoms in main and side chains are hydrolytically unstable [ 36 ]. Hydrolytic degradation of a polymer involves diffusion of the active medium into the polymer and reactions involving chemically unstable bonds.…”

Kinetic study of the poly(vinyl chloride)/titanium dioxide nanocomposites photodegradation under accelerated ultraviolet and visible light exposure

“…To control the stability, understanding of the degradation mechanism is the primary requisite and due to this fact, understanding of the degradation basis can be useful . The photo‐oxidation of polymers is known to be a set of complicated physical and chemical processes, which occurs under the influence of light . But the general mechanism of these processes has been understood.…”

“…Mathematical modeling of polymer aging processes may give a great view on how these complex processes and different parameters can affect polymers degradation . It is of great importance to be able to estimate the rate of photo‐oxidation of a solid polymer, because it enables researchers to predict the polymeric materials lifetime and also to evaluate the effect of various additives on the stability of polymers . The rate of degradation can be affected by the polymer structure, formulation, and also its production process …”

“…[27] The photooxidation of polymers is known to be a set of complicated physical and chemical processes, which occurs under the influence of light. [28] But the general mechanism of these processes has been understood. The mechanism of polymers photo-oxidative degradation was generally discussed by Singh and Sharma.…”

“…[2] It is of great importance to be able to estimate the rate of photo-oxidation of a solid polymer, because it enables researchers to predict the polymeric materials lifetime and also to evaluate the effect of various additives on the stability of polymers. [28] The rate of degradation can be affected by the polymer structure, formulation, and also its production process. [2] Considerable attention has been already paid to the study of different polymers and polymer composites photodegradation, but little evidence has been found for PVC/TiO 2 nanocomposites.…”