Identification of Additives in Polypropylene and Their Degradation under Solar Exposure Studied by Gas Chromatography–Mass Spectrometry

Abstract

Additives are absolutely essential in the development of commercial polymeric materials. Accordingly, an exhaustive control of composition and evolution in these additives over time is necessary to validate their performance and safety during their shelf life and, consequently, their ultimate applications. Gas chromatography coupled with mass spectrometry, GC–MS, is described in the present work to identify and analyze the content of a wide variety of additives, commonly used in industrial polymeric materials. First, the identification under the present experimental protocol of additives with a relatively high molecular weight (Irganox 1330 and Irganox 1010) has been successfully attained. Second, the evolution under solar exposure over time has been analyzed by GC–MS for 11 additives and derived substances, which have been identified in a commercial polypropylene sample, estimating the corresponding depletion times. In addition, the resultant increase of carbonyl groups in the polymeric macrochains along the photo-oxidation has been also determined by infrared spectroscopy. Therefore, GC–MS is found to be a reliable tool for the analysis of the evolution of commonly used polymer additives under specific degradation conditions, which can be very useful in the formulation of improved future additivations.

An Effective Package of Antioxidants for Avoiding Premature Failure in Polypropylene Random Copolymer Plastic Pipes under Hydrostatic Pressure and High Temperature

“…The presence of inorganic components could contribute to increased heterogeneity. Such components can also boost interactions, in the manufacturing process or in the aging test, of the existing oxidizing agents with the pipe material, leading to early degradation [ 15 , 50 ]. This phenomenon can be overstated by the presence of inorganic fillers with a tendency to form aggregates, which would avoid a suitable interfacial adhesion to the polymeric matrix [ 51 ].…”

“…This is in agreement with the literature [ 79 ] where hydrolysis is the preferred decomposition mechanism for Irganox 1010, while the Irganox 1330 consumption in water takes place through a gradual transformation into three different quinone structures. These species were also identified by our research team [ 15 ]. The stabilization ability of phenolic groups existing in the different oxidized species in Irganox 1330 has previously been demonstrated [ 80 ], so the reduction in content of parent species is not indicative of a drastic reduction in the antioxidant capacity of this additive.…”

“…The chosen chromatographic method lasted 37.5 min. The program started at 80 °C, temperature was increased at a constant rate of 8 °C/min up to 340 °C, and was maintained for 5 min [ 15 ].…”

AtmosphericCO2/CH4permeability ofEVAcopolymer/SiO2composite membrane for biogas purification

“…To simply demonstrate the effect of vinyl acetate content, the carbonyl index was calculated from the ratio of intensities at 1734 cm À1 /1460 cm À1 . [40][41][42] It is clear that this ratio is proportionally increased with the vinyl acetate content of the membranes (Figure 6). The carbonyl index implies the number of polar carbonyl group in the polymeric structure.…”

Micro and Nano-Plastics in the Environment: Research Priorities for the Near Future

“…The analyses required to trace the huge amount of oxidation, photodegradation and biotransformation products that can be originated from plastic additives are highly challenging. The identification of additives and their degradation products is a very complex issue due to the large number of different types of chemicals used, the relatively high molecular weight of many additives, their presence in mixtures and their inclusion in complex matrices, particularly when dealing with food transfer chemicals (Blázquez-Blázquez et al 2020).…”