No abstract

(4-Ethylphenyl)-3,5-ditertiarybutyl-4-hydroxybenzylamine, 1-phenyl-4-(3,5-ditertiarybutyl-4-hydroxybenzyl)piperazine, and 1-(3,5-ditertiarybutyl-4-hydroxybenzyl)piperidine were synthesized and characterized, and their performance in polypropylene copolymer (PPCP) was tested by multiple extrusions in a Brabender plasticorder. The thermooxidative stability of PPCP was assessed by the measurement of oxidative induction time at 200 Ϯ 1°C, and the thermal stability was assessed by observation of the change in the melt flow rate. A comparative study of the synthesized antioxidants with the commercially available antioxidant 2,6-ditertiarybutyl-4-methylphenol was made. The presence of phenolic and amino groups influenced the performance of the antioxidants. The performance of the antioxidants influenced the thermal stability of the PPCP.

No abstract

No abstract

A group of phenolic antioxidants was synthesized, characterized and the performance of these antioxidants in polymer processing was tested in the polymer melt by multiple extrusions. The change in melt flow was observed and compared with the change in melt flow by use of commercially available antioxidants. All the antioxidants examined had the same phenolic stabilization moiety but varied in the size of the substituents in the para-position of the aromatic ring. Increasing length of the side chain considerably influences the behaviour of the antioxidants in the polymer and thus their effectiveness. ZUSAMMENFASSUNG:Eine Gruppe neuer phenolischer Antioxidantien wurde synthetisiert und charakterisiert; ihr Einflulj auf die Polymerverarbeitung wurde an Polymerschmelzen bei wiederholter Extrusion untersucht. Die Anderung des Schmelzflusses wurde gemessen und mit dem Verhalten bei Verwendung handelsiiblicher Antioxidantien verglichen. Die untersuchten Verbindungen waren alle aus dem gleichen Phenylsegment aufgebaut, unterschieden sich aber in der Lange der para-Substituenten, die das Verhalten der Antioxidantien in Polymeren und somit ihre Wirkung entscheidend beeinflussen.