Stabilization Effects of Natural Compounds and Polyhedral Oligomeric Silsesquioxane Nanoparticles on the Accelerated Degradation of Ethylene-Propylene-Diene Monomer.

Traian Zaharescu,Ignazio Blanco

doi:10.3390/molecules26154390

Abstract

In this work the analysis on the stabilization activities of some natural antioxidants (rosemary extract, capsaicin, quercetin or oleanolic acid) is presented. A similar contribution of an inorganic structure—polyhedral oligomeric silsesquioxane (POSS) nanoparticles—is also evaluated. The stabilization effects on the oxidation protection were investigated for several formulations based on ethylene-propylene-diene-terpolymer (EPDM). The samples were examined in pristine state or after γ-irradiation, when the accelerated degradation scission of polymer macromolecules followed by the mitigation of oxidation. Three evaluation procedures: chemiluminescence, FTIR spectroscopy and thermal analysis were applied for the characterization of stability efficiency. The delaying effect of oxidative aging in EPDM matrix is illustrated by the values of activation energy, which are correlated with the type and concentration of embedded compounds. The durability of studied EPDM formulations is discussed for the assessment of material life. The improved behavior of structured hybrids useful for the optimization application regimes is essentially based on the antioxidant properties of polyphenolic components in the cases of natural antioxidants or on the penetration of free radical intermediates into the free volumes of POSS.

Highlights

The capability of rosemary extracts and many other natural extracts to prevent material aging has been recognized for a long time
The large variety of compounds having antioxidant properties allows the selective investigation on different structures, which are beneficial for a large spectrum of applications with several advantages related to the evolution of functional targets
This study analyzes the contribution of various compounds with antioxidant properties on the oxidation delay of ethylene-propylene-diene monomer, as a representative example of packaging materials

Summary

Introduction

The capability of rosemary extracts and many other natural extracts to prevent material aging has been recognized for a long time. The stabilization effects on reference material/paraffin [3], packaging polymers [4,5], medical materials [6,7], anticorrosive surface protection [8], inhibition of the oxidation in biodiesel [9] are already reported. These uses are based on the ability of active rosemary components or other natural extracts to block harmful processes fed by the diffusion of oxygen. It must be emphasized that all derivatives of carnosic acid existing in the conversion chain of carnosic acid present similar antioxidant features with sufficient protection potential [3]

Methods

Results

Discussion

Conclusion