Availability of PLA/SIS blends for packaging and medical applications. (July 2020)

• Record Type: Journal Article
• Authors: Luchian-Lupu, Ana-Maria; Zaharescu, Traian; Lungulescu, Eduard-Marius; Râpă, Maria; Iovu, Horia
• Is Part Of: Radiation physics and chemistry. Volume 172(2020:Jul.)
• Publication Date: 2020-07
• Subjects: PLA -- SIS -- Stabilization -- Chemiluminescence -- Packaging materials; Radiation chemistry -- Periodicals; Radiometry -- Periodicals; Radiation -- Periodicals; Chimie sous rayonnement -- Périodiques; 539.2
• DOI: 10.1016/j.radphyschem.2020.108696
• Languages: English
• ISSNs: 0969-806X

Abstract

Abstract: The samples consisting of poly (lactic acid) (PLA) and styrene-isoprene-styrene triblock polymers (SIS) were investigated for the evaluation of their stability qualification. The accelerated degradation was achieved by γ-exposure when structural modifications were watched. Three SIS loadings (10, 20 and 30 wt%) were blended in PLA matrix. The concentration effect of minor component reveals the higher stability for the lower amounts of SIS. The applied procedures: chemiluminescence, DSC and FTIR spectroscopy, providing accordant results describe the stabilization effect of SIS upon PLA phase. Mechanistic aspects of degradation are discussed for the analysis of each blending component contribution to the progress of oxidative degradation. Various types of radicals born during radiolysis in the both components that are involved in the oxidative degradation are the initiators of degradation. The reported results reveal the main role of SIS in the promotion of material ageing. The results obtained by radiation processing indicate it as a proper treatment for sterilization applied to food packaging and medical wear. Highlights: The degradation of PLA/SIS starts priory in hydrocarbon component. The compound containing the lowest SIS concentration is the most stable. The irradiation causes a light crosslinking of hydrocarbon component improving the material stability. The thermal degradation of all compositions starts just before 100 °C.