Natural antioxidants for polypropylene stabilization

• Published in: Polymer degradation and stability Vol. 96; no. 12; pp. 2152 - 2158
• Main Authors: Ambrogi, V., Cerruti, P., Carfagna, C., Malinconico, M., Marturano, V., Perrotti, M., Persico, P.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2011; Elsevier
• Subjects: Ageing; antioxidant activity; Antioxidants; Applied sciences; Bark; Byproducts; Carotenoids; Compounding ingredients; Degradation; Dispersions; Exact sciences and technology; grapes; infrared spectroscopy; Long-term stability; Natural additives; Phenols; Physical properties; Pinus pinaster; Polymer industry, paints, wood; polyphenols; Polypropylene; Polypropylenes; Properties and testing; Stabilization; stabilizers; Stabilizers (antioxydants, antiozonants, etc.); Technology of polymers; Thermal oxidation; thermogravimetry; tomatoes; value added; winemaking; Wines; Phenols; Carotenoids; Polypropylene; Natural additives; Long-term stability; Thermal oxidation; Thermal ageing; Propylene polymer; Thermooxidative degradation; Softwood; Thermal stabilization; Antioxidant; Experimental study; Thermal stability; Thermal properties; Additive; Stabilizer agent; Plant origin; Olefin polymer; Carotenoid
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2011.09.015

A study on the efficiency of bio-based compounds as stabilizers for polypropylene (PP) is reported. A water extract from French maritime pine bark (Pycnogenol ®), a by-product containing polyphenols obtained from wine production, and a carotenoid-containing oleoresin from processing of tomatoes were used. Their stabilizing activity was compared with that of a commercial phenolic antioxidant. Thermogravimetric analysis and Oxidative Induction Time measurements performed on unaged samples, as well as infrared spectroscopy on samples aged at 70 °C, provided evidence for the effectiveness of the natural stabilizers. Mechanical characterization was carried out on aged films and injection moulded samples. Experimental results indicated that particularly grape extract could provide long-term stabilization to PP under conditions of oxidative degradation. Therefore, it could be used as efficient and high value-added additive for polypropylene. Pycnogenol ® also showed antioxidant activity, however the achievement of a more homogeneous dispersion in the polymer matrix could improve the mechanical performance of aged samples.