Mechanical properties high-energy radiation

Polyacetals are sensitive to high-energy radiation and sterilization by this process can only be used if high mechanical properties are not required impact resistance in particular is altered. Exposure to doses exceeding 30kJ/kg causes yellowing and a decrease of the impact resistance. 

Good mechanical, chemical and electrical properties rigidity good creep resistance fatigue behaviour fair moisture uptake fair shrinkage heat behaviour with continuous use temperature up to 250°C high-energy radiation behaviour. 

The modification of the properties of cotton cellulosic textile products, through free radical-initiated graft copolymerization reactions with vinyl monomers, has been investigated at the Southern Laboratory for a number of years (6, 9). In this chapter, we summarize the basic mechanisms and principles involved in free radical reactions of cellulose, initiated by high energy radiation, ceric ion in acidic solution, and aqueous solutions of ferrous ion and hydrogen peroxide. Some of the properties of fibrous cotton cellulose graft copolymers are also presented. 

Adhesives are used in space applications that may be exposed to high-energy radiation. Evaluating the effect of total dose and dose rate on the mechanical, electrical, and chemical properties of adhesives is required for reliability. ASTM D1879, Exposure of Adhesive Specimens to High-Energy Radiatiori defines conditions for exposure. Categories of dose rate exposure within this method are ... 

Under incident radiation or bombardment by an electron beam surfaces emit photons, electrons, or both. The emission properties of solid surfaces differ widely, just as their mechanisms or relaxation after excitation by high-energy radiation differ. Many surface-sensitive experimental techniques providing information related to the electronic properties of surfaces are based on these processes, for example. Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and ultraviolet photoelectron spectroscopy (UPS). These are discussed below. 

H. Anuar, S.B. Abd Razak, N.M. Kahar, N.A. Jamal, Effects of high energy radiation on mechanical properties of PP/EPDM nanocomposite. Advanced Materials Research 264-265 (2011)738-742. 

---