Aging and Weathering

Polymers that cross-link Polymers that degrade 

Poly(methyl acrylate) Poly(methyl methacrylate) 

From the foregoing sections it will be realised that the aging and weathering behaviour of a plastics material will be dependent on many factors. The following agencies may cause a change in the properties of a polymer  

In a commercial plastics material there are also normally a number of other ingredients present and these may also be affected by the above agencies. Furthermore they may interact with each other and with the polymer so that the effects of the above agencies may be more, or may be less, drastic. Since different polymers and additives respond in different ways to the influence of chemicals and radiant energy, weathering behaviour can be very specific. 

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The polymer can be vulcanized to give a rubber with very good chemical (solvent) resistance, excellent resistance to aging and weathering, and good color retention in sunlight. 

Due to its balance of strength, oil resistance, inflammability, increased resistance to ozone, ageing and weathering, polychloroprene finds widespread industrial use. Typical uses are V-belts, conveyor belts, wire and cable jacketing, footwear, wet suit applications, coated fabrics, inflatables, hoses, extrusions and many other goods. Adhesives are also a strong market area. 

SEES is chosen for a better oxidation, ageing and weathering resistance a broader rigidity range and better retention of properties when the temperatures rise above the glass transition of polystyrene. 

Matthan J, Scott K A and Wiechers M. Ageing and Weathering of Plastics, RAPRA Technology, 1970. 

Aging and Weather Resistance. Polymeric sulfur compounds are hydrophobic thus, they have the potential to serve as exterior adhesives. However, in the case of wood, the lack of swelling can prove to be a handicap in high-sulfur samples we observed poor water resistance and rapid crumbling. If the sulfur-to-wood ratio is small and if a large frac-... 

Noordijk, H., van Bergeijk, K. E., Lembrechts, J., and Frissel, M. J. (1992). Impact of ageing and weather conditions on soil-to-plant transfer of radiocesium and radiostrontium. J. Environ. Radioact. 15, 277-286. 

Important properties of these raw materials are the elasticity behavior given over a wide temperature range in cold and heat and the excellent aging and weathering resistance. Thus, various applications, above all outdoors, are possible. They are applied in nearly all fields of industry, for which special formulations are available according to the requirements and the material combinations to be sealed. The manufacturers show partly very detailed information on these products, which has to be referred to at this point. 

Chem. Descrip. Sat., aliphatic, linear, hydroxyl-terminated polyester diol Uses Polyester for thermoplastic elastomers, laminating adhesives, hot melt and sol n. coatings, and one-shot and prepolymer castables Features PUs exhibit hydrolysis resistance, heat aging and weathering, strong, resilient elastomers, thermoplastic processability, and low temp, properties melts at mod. temps. 

Schmidt RA (1964) Microscopic extraterrestrial particles from the Antarctic Penninsula. In Cassidy WA (ed) Cosmic dust. Ann NY Acad Sd 119 186-204 Schultz L (1986) Allende in Antarctica Temperatures in Antarctic meteorites. Meteoritics 21(4) 505 Schultz L (1990) Terrestrial ages and weathering of Antarctic meteorites. In Cassidy WA, Whillans IM (eds) Workshop on Antarctic meteorite stranding surfaces. LPI Tech. Rept. 90-03. Houston, TX, pp 56-59... 

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