Papers by Keyword: Chemical Degradation

Abstract: This paper is closely related to chemical degradation of PAM. The degradation refers to any process that breaks down the molecular structure of macromolecules. The most important degradation pathways in oil recovery applications are oxidation reduction, ironic ions and divalents. The influences of each factor is discussed, and preventive measures are also put forward. It is beneficial to provide the degradation of the polymer, and it can largely improve the utilization rate of PAM.

Abstract: Systematic analysis of quantitative structure – property relationships for dyes of different nature has been reviewed. On the basis of the experimental results published in the literature and theoretical evaluation of amphiphilic and electrophilic properties of dyes of different nature several basic conclusions of scientific and practical importance are proposed. It was found that water/octanol partition coefficients exhibit correlation with dye partition between hydrophobic synthetic fibres and dyebath as well as dye affinity. Hydrophobicity of dyes controls several technical properties of dyes and dyeings, such as wash fastness and light fastness, migration factor, rate of dyeing and fixation rate. Energy of frontier electronic orbitals (HOMO and LUMO energies) correlates with different properties characterizing redox properties of dyes: oxidative and reductive destruction in chemical reactions, photochemical and biochemical destruction of dyes, wash and light fastness of dyeings. The results of this study are useful for physico-chemical analysis of dye sorption by textile fibres, destruction of dyes in polymers and solutions as well as for design of new dyes of high quality.

Abstract: Water-soluble polyacrylamide is commercially available in different domains of industry, such as water purified, paper making, pharmacy, agriculture and oil exploitation. Especially polyacrylamide is used for polymer displacement, which can enhance oil recovery through increasing the sweeping efficiency. Good economic effects are achieved by the industrial application of polymer in various oil fields. However, some problems of the oil-well production and the waste water treatment come forth with the present of polyacrylamide in the production fluid. It is maybe an efficient mean to solve it with the degradation of polyacrylamide. So, this paper reviews the lately development on the research of the degradation of polyacrylamide, especially including ultrasonic degradation, thermal degradation, biodegradation and chemical degradation.

Abstract: The objective of this paper is to investigate the influence of chemical degradation effects on polyester polymer mortar (PM). For this purpose, different dosages of siliceous and limestone PMs and natural stone specimens were exposed to representative degradation agents. Since the motivation for the research was to determine the durability of polymer mortar, it was considered important to simulate the types of aggressive environments that could conceivably be brought into contact with the material in domestic and industrial environments. In this paper, the possible variation of the surface aspect, water absorption and mass of the tiles after being immersed the specimens in different solutions, was measured and considered by visual observation and optical microscopy. As a conclusion PMs stability is strongly affected by the adhesion between matrix and aggregates at interface, and it is also dependent of the nature and packing level of aggregates.