Degradation of Polymers

Degradation of Polymers

 

the breakdown of macromolecules owing to heat, oxygen, moisture, light, penetrating radiation, mechanical stresses, biological agencies (for example, by the action of microorganisms), and other factors. Depending on the agent, the following forms of polymer degradation are distinguished: thermal, thermal oxidative, photochemical, hydrolytic, and radiation, among others. Usually several types of degradation processes take place simultaneously in a polymer; for example, making a polymer into a product, it undergoes thermal, thermal oxidation, and mechanical forms of degradation.

The degradation leads to a decrease in the polymer’s weight, and its structure and physical and chemical properties alter, that is, it ages and often becomes unsuitable for practical use. However, polymer degradation is not always undesirable. Thus, for example, the process is used in the mechanical synthesis of various block and graft copolymers, in the plasticization of rubber, and in the production of valuable low-molecular-weight substances (for example, glucose) from natural polymers. The study of degradation makes it possible to work out the scientific foundations and practical methods of stabilizing polymers.

V. S. PAPKOV

References in periodicals archive ?
Bhowmick's main research interests are thermoplastic elastomers and polymer blends, nanocomposites, polymer modification, polymer technology, failure and degradation of polymers, adhesion, and adhesives.
The ultrasonic oscillation played a vital role in both the degradation of polymers and diffusion of free radicals.
The dryer introduces an inert gas or nitrogen to inhibit the oxidative degradation of polymers. Resins that tend to degrade with prolonged exposure to heat in the presence of oxygen include nylons, PBT, PLA, and TPUs.
David, "Thermal degradation of polymers," in Comprehensive Chemical Kinetics, pp.
On the other hand, degradation of polymers was investigated by TGA where Tg and Mn, Mw values were obtained from DSC curves and GPC, respectively.
Composites of inorganic particles with polymers is an interesting research subject because of the important potential applications in photocatalytic degradation of polymers, the production of controlled release products such as pesticides and drugs, and in the fields of adhesives, textiles, optics, and electronics.
These additives can be used to prevent degradation of polymers during the manufacturing process, protect against environmental impact, or enhance physical properties like heat or light resistance of the polymer.
He was a Postdoctoral Fellow at Glasgow University, 1970-1972, studying thermal degradation of polymers. During his time in Scotland.
This work is centred on the study of the degradation of polymers often used as structural adhesives, specifically the degradation behaviour of bulk specimens immersed in natural seawater.
Infrared analysis of depth profiles in UV-photochemical degradation of polymers. Polymer Degradation and Stability 88(2): 224-233.
(21) Although detailed mechanism for chemical degradation of PU in the UVO cleaner needs further study, it is reasonable to conclude that in the UVO-cleaner condition, ZnO nanoparticles reduce the degradation of polymers (act as a pholostabilizer), while in the SPHERE exposure condition, they accelerate the photodegradation of polymers (act as a photocatalyst).