This chapter discusses attempts to quantitatively model degradation processes in bioresorbable polymers, focusing on hydrolytic degradation of polymeric biomaterials, particularly the polylactide/polyglycolide family of polymers. Key processes of degradation are reviewed including diffusion of water, kinetics of ...
Our investigations clearly demonstrate that it is possible to follow damp-heat and UV induced aging processes of different polymers used in PV-modules as encapsulation materials by luminescence detection. 展开 关键词: Luminescence Polymers Solar cells Data hiding Ultraviolet radiation ...
聚合物稳定与降解(Polymerstabilityanddegradation) Thefirstchapter,theintroduction 1.Theconceptofaging(degradation) Intheprocessofprocessing,storageanduseofpolymer materials,thephysicalandmechanicalpropertieswill graduallydeteriorate,whichiscalledaging,ordegradation. p1 Features: Inevitably,irreversibleprocesses. Thetime...
When coupled with the complexity of the reaction processes in polymers, establishment of predictive models or damage functions is a formidable challenge. There is a prevalent view that there is no correlation between natural and artificial weathering. This view is expressed even in some of the ...
The commercial importance of polymer blends implies interest in knowledge of their degradation behaviour under environmental stresses. Processes accompanying thermomechanical and thermal degradation of blends of commodity polymers are reviewed. Thermomechanical degradation, characteristic of melt processing, include...
p1 Features: Inevitably, irreversible processes. The time scale is relatively short. 2. Causes of polymer degradation (1) internal causes A. The composition of polymer and its chain structure. (1) different composition and degradation situation (2) the active matrix may be the main internal ...
The mechanisms of these reactions and stabilisation processes must be understood if the technology and application of polymers are to continue to advance. The reporting of investigations of this kind is therefore a major function of this journal.However there are also new developments in polymer ...
Thermal analysis carried out on the buried PP and BOPP showed decreases in the percentage of crystallinity due to chain scission. The major reduction was observed in the PP, since its crystallinity is a consequence of polymerization instead of chain orientation processes, as in BOPP. Cracks and ...
Diverse accelerated aging processes have been used in the last years with the objective to estimate the lifetime of fibers in real field situations. Because the humidity present at the glass- polymer interface determines the strength, a dry technique in fiber optics is used to understand the ...
In the mouth, chemical degradation is a complex process (thermolysis, oxidation, solvolysis, photolysis, and radiolysis), which include disintegration and dissolution of materials in saliva. Of the listed chemical processes, solvolysis is likely the most relevant to current dental composites (Santerre ...