Thermal and photo-oxidative stabilisation of polyolefin films: mode of action of novel naphthalene-hindered piperidine derivatives

• Published in: Polymer degradation and stability Vol. 60; no. 1; pp. 195 - 204
• Main Authors: Ortiz, Ricardo Acosta, Salas, Eduardo A.Romero, Allen, Norman S.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.1998; Elsevier Science
• Subjects: Applied sciences; Compounding ingredients; Exact sciences and technology; Polymer industry, paints, wood; Stabilizers (antioxydants, antiozonants, etc.); Technology of polymers; Performance evaluation; Film; Heat stabilizer; Propylene polymer; Thermooxidative degradation; Experimental study; Naphthalene derivatives; Piperidine derivatives; Tertiary amine; Reaction mechanism; Adjuvant; Light stabiliser; Mechanism of action; Photochemical degradation
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/S0141-3910(97)00141-9

Four novel naphthyl and naphthoate derivatives of tetramethyl and pentamethylpiperidine (HALS) have been synthesised, characterised and evaluated as thermal and light stabilisers in both high density polyethylene (HDPE) and polypropylene (PP) film using FTIR analysis. The naphthalene moiety is found to induce good dual thermal and light stabilising activity in the polymers. In terms of thermal oxidative stability, the secondary HALS were better than the tertiary HALS systems and vice-versa for photostabilisation. From mass spectrometric evidence and photochemical studies the naphthalene and naphthyl moieties sever rapidly during the early stages of degradation, resulting in effective oxygen scavenging products protecting the HALS moiety from oxidation.