The potential of flavonoids as natural antioxidants and UV light stabilizers for polypropylene

Abstract

This paper presents a study on the stabilization of polypropylene (PP) against thermo-oxidation and UV radiation by using natural phenolic compounds derived from structures of flavonoids: a flavone (chrysin), a flavanol (quercetin), two flavanone glycosides (hesperidin and naringin) and flavanoligand (silibinin). Thermal stabilization has been assessed in an oxidizing atmosphere by means of differential scanning calorimetry (DSC) both in isothermal as well as dynamic conditions. In addition, the effectiveness of these phenolic compounds as thermal stabilizers at high temperature 2 has been quantified with the use of thermogravimetric analysis (TGA). Stabilization against UV radiation has been estimated by studying the morphology changes of the exposed surfaces by scanning electron microscopy (SEM); also surface chemical changes have been followed by infrared spectroscopy (FTIR). Global results show that flavonoid compounds of type flavonols (quercetin and silibinin) provide the best results in stabilizing both against oxidation and against the action of UV radiation.

Manufacturing and compatibilization of PLA/PBAT binary blends by cottonseed oil-based derivatives

“…antioxidants, plasticizers, fillers, etc. [7][8][9][10]. With the increasing development of nanotechnology, many research works have been focused of using nanostructures to improve the properties of PLA-based materials [11][12][13] and interactions.…”

Efficient melt stabilization of polyethylene with quercetin, a flavonoid type natural antioxidant

“…The compound is a flavonol type flavonoid, which has proven antioxidant, antiviral and anti-inflammatory effect in the human body. Some research groups have attempted already to use quercetin as an antioxidant in polyolefins [12,13], while others tried to apply it as a component of active packaging material [14][15][16][17]. In the latter case mostly the migration and dissolution of the antioxidant was studied in various solvents modeling food.…”

“…The authors did not find any aggregates in the polymer, stability increased considerably, while oxygen permeation decreased simultaneously. Samper et al [13] studied the thermo-and photooxidative stabilization of polypropylene (PP) with different flavonoids and found that flavonol type compounds, like quercetin, are the most efficient antioxidants. Lopez de Dicastillo and co-workers [15] stabilized successfully an ethylene vinyl alcohol copolymer with quercetin.…”

“…In most studies quercetin was added at concentrations of 2-3000 ppm [12,13] or in even larger quantities, which raises again the question of solubility, but also price, since the compound is rather expensive. As a consequence, the goal of our work was to study the stabilization effect of quercetin in a wide concentration range not investigated before.…”

New genre of antioxidants from renewable natural resources: Synthesis and characterisation of rosemary plant-derived antioxidants and their performance in polyolefins

“…Another by-product antioxidant obtained from olive processing, hydroxytyrosol (3,4-dihydroxy-phenylethanol), was found to offer good melt stability to PP [4]. Different flavonoids such as chrysin, hesperidin, naringin and quercetin were also considered as possible natural phenolic antioxidants and UV-stabilisers for PP [5]. Quercetin was found to be effective in stabilising PP against thermal oxidation and UV radiation, and against oxidation in PE melt.…”