Nikoo Karami - Department of Polymer Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
Reza Jahanmardi - Department of Polymer Engineering, Science and Research Branch, Islamic Azad University, Tehran,Iran

The present work is aimed to fnd a new and effcient type of antioxidants for polypropylene. Hence, effects of 3,3-bis(4-hydroxy-2-methyl-5-propan-2-ylphenyl)-2-benzofuran-1-one, generally known as thymolphthalein,on thermo-oxidative stability of polypropylene in solid and melt states were evaluated and compared with those ofSONGNOX 1010, an effcient commercially used antioxidant for the polymer. Oven ageing experiments followed byFourier transform infrared (FTIR) spectroscopy showed that thymolphthalein increased thermo-oxidative stabilityof the polymer outstandingly in the solid state and its stabilization effciency was comparable to that of SONGNOX1010. In addition, measurements of oxidative induction time (OIT) and oxidation onset temperature (OOT) revealedthat thymolphthalein improved thermo-oxidative stability of the polymer in the melt state signifcantly. It was alsoobserved that thymolphthalein did not interfere with the stabilization action of SONGNOX 1010 in the polymerneither in melt nor in solid state. On the basis of the obtained results, a probable mechanism for the stabilizationaction of thymolphthalein in the polymer is proposed. Polyolefns J (2017) 4: 79-86

Antioxidant; degradation; polypropylene; stabilization