Polymer damage

The first step was to spin-coat an electron-sensitive polymer (polymethylmethacrylate (PMMA)) onto an oxidized Si(l 00) wafer (which serves as a Si02 support). The desired pattern is subsequently written into the polymer layer by a highly collimated electron beam, followed by the selective dissolution of the polymer damaged by the electron exposure. A thin film of platinum is then deposited on this mask, and after the remaining polymer resist is removed completely by dissolution, metal particles remain on the substrate and are located at the positions of the prior electron irradiation, typically forming an ordered array of nanoparticles. 

Dugdale, D. S., Yielding of Steel Sheets Containing Slits,/. Mech. Phys. Solids, 8, 100, 1960. Engel, L., Klingele, G. W. and Schaper, H., An Atlas of Polymer Damage, Wolfe, London, 1981. 

UV-B 315-200 Includes the shortest wavelengths found at the earth s surface Causes severe polymer damage Absorbed by window glass... 

L. Engel, H. Klingele, and G. W. Ehrenstein, An Atlas of Polymer Damage, Prentice-Hall, Inc., Englewood Cliffs, N.J., 1981. 

Engel, L. et al. An Atlas of Polymer Damage Surface Examination of Fractures Other Types of Damage by Scanning Electron Microscopy. San Diego Technomic, 1981. 

B.V. Crist, Handbook of Monochromatic XPS Spectra. Polymers Polymers Damaged by X-Rays, Wiley-Interscience, New York, NY (2000). 

Crist B.V. (2000) The Handbook if Monochromatic XPS Spectra, Part 2, Polymers and Polymers Damaged by X-rays. John Wiley, Chichester... 

Stimulation Release and migration of fines Precipitation of solids formed from the reactions of stimulation fluids with formation minerals or fluid Polymer damage (frac fluid) Formation wettability alterations ... 

One common form of deterioration results from exposure to light [in particular, ultraviolet (UV) radiation]. Ultraviolet radiation interacts with and causes a severance of some of the covalent bonds along the molecular chains, which may also result in some crosslinking. There are two primary approaches to UV stabilization. The first is to add a UV-absorbent material, often as a thin layer at the surface. This essentially acts as a sunscreen and blocks out the UV radiation before it can penetrate into and damage the polymer. The second approach is to add materials that react with the bonds broken by UV radiation before they can participate in other reactions that lead to additional polymer damage. 

Figure 2, The interactions between energy dissipation mode and polymer damage processes which reveal the basic mechanisms of wear.

Outdoor weathering affords many different routes to failure for flexible PVC. Loss of plasticizer and polymer damage through photooxidation is one possibility. 

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