Scanning electron microscopy acrylonitrile-butadiene-styrene

Figure 9,27 Scanning electron microscopy images of acrylonitrile-butadiene-styrene terpoly-mer foam (foaming stage at 90°C).

Figure 935 Scanning electron microscopy images of (a) an acrylonitrile-butadiene-styrene (ABS) solid terpolymer, (b) the same ABS terpolymer after the CO2 sorption stage, and (c) after the foaming stage - insert figure comparison with transmission electron microscopy image of unfoamed sample at the same magnification.

The stabilization of poly(vinyl chloride) against light has been reviewed by Wirth and Andreas. Detailed mechanistic studies have indicated the importance of peroxides in the process of photo-oxidation. It was suggested that protection could be successfully achieved by exclusion of radiation of A < 380 nm. E.s.r. examination of irradiated samples demonstrated the intervention of peroxides in the mechanisms with the ultimate formation of carbonyl groups which caused chain scission by Norrish cleavage. Photo-oxidation of samples of poly(vinyl chloride) modified by incorporation of acrylonitrile-butadiene-styrene, methyl methacrylate-butadiene-styrene, and methyl methacrylate-acrylonitrile-butadiene-styrene copolymers has been investigated. Discolouration was accelerated by the presence of the modifiers. Thermal pre-treatment accelerated photo-induced decomposition. Mechanical properties were also examined, and scanning electron microscopy showed surface defects due to decomposition of the modifier. ... 

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