This article evaluated the thermal, mechanical, morphological and fracture properties of systems with poly (ethylene glycol)–poly(propylene glycol)–poly(ethylene glycol) (PPG-PEG-PPG) triblock copolymer, with molecular weight 2000 g•mol−1 and 50% PEG in its composition, in DGEBA/DDM epoxy matrix. Systems with 10, 20 and 30 wt.% copolymer were prepared by in-situ polymerization and curing at 100 °C. In the differential scanning calorimetry (DSC) analysis, the characteristic temperatures of both the copolymer and the matrix in the binary systems were verified, indicating that phase separation had occurred. However, the glass transition temperature referring to the epoxy phase (Tg-E) occurred at lower temperatures than in neat matrix, which indicates partial miscibility in binary systems. The epoxy/copolymer systems presented a Young's modulus higher than the neat matrix, and without loss of mechanical resistance, reinforcing the miscibility of the PEG block in the blends and a microstructure with nanophase separation. When evaluating the fracture surface of the blends by scanning electron microscopy, the presence of deflection and crack immobilization mechanisms was observed, but no phase separation of the copolymer was observed. In this way, the systems studied showed partial miscibility with the formation of nanophases at the curing temperature of 100 °C, influencing Tg-E and improving the stiffness of the matrix.

Epoxy matrix blends with poly (ethylene glycol)-block-poly (propylene glycol)-block-poly (ethylene glycol) triblock copolymer (PEG-b-PPG-b-PEG) with 30% PEG blocks were elaborated and investigated. The systems were prepared by the casting method with cure at 100 °C, with different amounts of copolymer in the epoxy matrix, and with the aim of evaluating the influence of the modifier on the properties of the blends. By DSC it was verified that the glass transition temperature relating to the matrix phase decreased in systems with copolymer in relation to neat epoxy, thus the blends formed partially miscible systems. On the other hand, phases separation or microdomains of the block copolymer within the epoxy matrix were not discernible by scanning electron microscopy. In general, the addition of the block copolymer impaired the mechanical properties evaluated in the tensile test. However, the fracture mechanisms observed on the fracture surface of the blends indicate that an improvement in the toughness of the systems may have occurred due to the crack pinning and crack deflection mechanisms.

Pseudo-fruits of Hovenia dulcis T. are sweet-tasting, edible, and contain numerous nutrients and a significant amount of phenolic compounds, which could serve as a source of natural antioxidants. In this context, this study aimed to evaluate the addition of H. dulcis T. extract and licorice root extract (licrezzTM) in the formulation of Bologna-type mortadella and to investigate the inhibition of lipid oxidation during cold storage, to assess their antioxidant properties. Mortadella samples were prepared in duplicate with sodium erythorbate (control), licrezzTM (commercial extract from Glycyrrhiza glabra), and H. dulcis extract, at a concentration of 0,1%. The samples were evaluated for proximate composition, microbiological characteristics, texture profile, lipid oxidation, nitrite content, instrumental color, pH, and water activity. Mortadella with H. dulcis extract did not show significant differences from the control in terms of proximate composition, microbiological characteristics, or texture profile. However, they exhibited slightly lower, but comparable results in the Thiobarbituric Acid Reactive Substances (TBARS) assay during the 28 days of refrigerated storage. The control and H. dulcis extract samples showed approximately a ninefold increase in TBARS values by the end of storage, while licrezzTM showed a twenty-sixfold increase. On the other hand, H. dulcis extract exhibited similar behavior to licrezzTM regarding residual nitrite content. Thus, H. dulcis pseudo-fruits extract shows potential for use as a natural antioxidant in emulsified meat products, alone or in combination with Glycyrrhiza glabra.