During the degradation process, they should not generate any substances that are harmful. These polymers can be classified into three major categories: polyesters produced by microorganisms, natural polysaccharides and other biopolymers like starch, and synthetic polymers like aliphatic polymers. Another ...
The off-line coupling of SEC, gradient chromatography, and LACCC with MALDI-TOF MS was applied in the analysis of hydrolytic degradation products of poly(bisphenol A)carbonate. Sometimes, a degradation of polymers by the MALDI laser itself (during the ionization/desorption process) can be ...
聚合物稳定与降解(Stabilityanddegradationofpolymers)Chapterone,introduction1.conceptofaging(degradation)Intheprocessing,storageanduseofpolymermaterials,thephysicalandchemicalpropertiesandmechanicalpropertieswillgraduallybecomeworse,calledaging,ordegradation.P1Characteristic:Inevitable,irreversibleprocess.Thetimescaleis...
内容提示: 聚合物稳定与降解(Stability and degradation of polymers) Chapter one, introduction 1. concept of aging (degradation) In the processing, storage and use of polymer materials, the physical and chemical properties and mechanical properties will gradually become worse, called aging, or ...
the relative molecular weight of the polymer decreases sharply. No regulation chain reaction - almost all condensation and a large amount of polymer degradation The polymer has no rule breaking chain; The main products of the reaction are low molecular weight polymers. Features...
Balancing the degradation of polymers in relation to different process modi of a pilot plant for anaerobic digestion of municipal biowasteThe results are presented of operation parameter changes on the degrdn. of hemicellulose, cellulose, lignin, suspended solids, volatile suspend...
聚合物稳定与降解(Polymer stability and degradation).doc,聚合物稳定与降解(Polymer stability and degradation) The first chapter, the introduction 1. The concept of aging (degradation) In the process of processing, storage and use of polymer materials,
The most common mode of environmental degradation is caused by exposure of engineering polymers to chemicals, resulting in environmental induced stress cracking. The steps in the degradation process involve stress enhanced absorption and concentration of the chemical molecules at susceptible microstructural si...
3. impurities in polymers In the two kinds of polymer impurity: (1) a small amount of impurities mixed in the process of the inevitable; (2) additive. Most of the impurities will accelerate the degradation of polymers. (two) external causes: Effects of A. heat, temperature and heat and ...
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 disti...