Other Auxiliary Materials in the Plastics Industry

Peroxides of different types are important as polymerisation initiators in the manufacture of plastics. Knappe and Pbteri [39] have separated various technically important organic peroxides on silica gel G layers, using toluene-carbon tetrachloride (67 + 33) and toluene-acetic acid (95 + 5). 

Substituted 2-hydroxybenzophenones, used as UV-light absorbers in the plastics and varnish industries, have been separated by Knappe and co-workers [41] on layers impregnated with adipic acid triethylene glycol polyester, using the solvent m-xylene-formic acid (98 + 2). The substances show characteristic fluorescence colours and can be visualised in addition as brick-red spots (only salol gives violet) by spraying with Fast Red AL Salt solution. 

---