Effect of Impregnation of Biodegradable Polyesters with Polyphenols from Cistus linnaeus and Juglans regia Linnaeus Walnut Green Husk

Abstract

The publication describes a process combining the extraction of plant material and impregnation of biodegradable polymers (polylactide (PLA) and polyhydroxyalkanoate (PHA)). As raw plant materials for making extracts, Cistus and green walnut husk were selected due to their high content of active phytochemicals, including antioxidants. The extracts used to impregnate polymers contained valuable polyphenolic compounds, as confirmed by FTIR and UV–Vis spectroscopy. After impregnation, the polymer samples showed greater thermal stability, determined by the differential scanning calorimetry (DSC) method. In addition, despite the presence of natural antibacterial and antifungal substances in the extracts, the polyester samples remained biodegradable. The manuscript also describes the effect of UV aging on the change of surface free energy and the color of polymers. UV aging has been selected for testing due to the high susceptibility of plant compounds to this degrading factor. The combination of the extraction of plant material and polymer impregnation in one process proved to be an effective and functional method, as both the obtained plant extracts and impregnated polymers showed the expected properties.

Fused Deposition Modeling of Poly (lactic acid)/Macadamia Composites—Thermal, Mechanical Properties and Scaffolds

“…The spectra of the untreated MS are similar to that described in other literature [16]. The downward peak between 3500-3200 cm −1 representing the hydrogen bonded O-H groups [28] became narrower in the spectra of the treated MS, revealing that the ratio of the O-H in MS increased. The band at 1740 cm −1 , due to the stretching vibration in carbonyl C = O groups [29], disappears after the alkali treatment.…”

In‐situ extraction and impregnation of black walnut husk into polyethylene film using supercritical carbon dioxide with an ethanol modifier

“…Additionally, walnut husk extracts do present an opportunity to be impregnated into films to produce antifungal and antioxidant packaging (Latos & Masek, 2019). The ability of supercritical carbon dioxide with an ethanol modifier to simultaneously extract antioxidants from green walnut husk into low-density polyethylene films (LDPE) was evaluated, and the films tested for change in composition and antioxidant potential.…”

Thermal Analysis of Aliphatic Polyester Blends with Natural Antioxidants

“…On the other hand, coffee, cocoa and cinnamon extracts effectively stabilize aliphatic polyesters [8]. Also, mixtures of polyphenols derived from Cistus linnaeus and Juglans regia Linnaeus walnut green husk incorporated into a bio-based and biodegradable polymeric matrix via an impregnation process work as environmentally friendly stabilizers [29].The examples presented concerning beneficial impact of natural antioxidants on polymers indicate that there is a real possibility to apply these substances as pro-ecological additives for polymeric materials. This is a relatively innovative and new area of research which should be continued and developed.…”

“…On the other hand, coffee, cocoa and cinnamon extracts effectively stabilize aliphatic polyesters [8]. Also, mixtures of polyphenols derived from Cistus linnaeus and Juglans regia Linnaeus walnut green husk incorporated into a bio-based and biodegradable polymeric matrix via an impregnation process work as environmentally friendly stabilizers [29].…”