High dielectric, low curing with high thermally stable renewable eugenol-based polybenzoxazine matrices and nanocomposites

Exploration of multifunctional wood coating based on an interpenetrating network system of rosin-CO2-based polyurethane and mussel bionic rosin-based benzoxazine

Polyurethane (PU) prepared by blending rosin base and CO₂-polyol already has good mechanical properties and hydrophobic effect and has powerful benefits in acid and alkali resistance and salt resistance. In this study, mussel bionic rosin-based benzoxazine (BZ) was synthesized using dehydroabietylamine, catechol, and paraformaldehyde. Mixing BZ into PU can endow the resulting PU/BZ with special effects such as zero curing shrinkage, excellent mechanical behavior, and flame retardancy through a 3D interpenetrating network system. From the results, the modulus of rupture (MOR) and modulus of elasticity (MOE) of PU wood coatings are 97.04 and 2601.97 MPa, respectively; in contrast, the PU/BZ wood coatings exhibited higher values of MOR and MOE of 110.87 and 2738.11 MPa. PU/BZ wood coatings show higher flexural strength and elastic modulus. They are also stronger than PU coatings in terms of acid/alkali and aging resistance. At the same time, the coating is endowed with flame retardant properties, and the LOI is 30.2 due to the presence of BZ. Thus, PU/BZ can be a versatile and practical wood coating. The interpenetrating network system of PU/BZ has an innovative impact on the preparation of wood coatings.

Characteristics and Application of Eugenol in the Production of Epoxy and Thermosetting Resin Composites: A Review

The review article presents an analysis of the properties of epoxy and thermosetting resin composites containing eugenol derivatives. Moreover, eugenol properties were characterized using thermogravimeters (TGA) and Fourier-transform infrared spectroscopy (FTIR). The aim of this work was to determine the possibility of using eugenol derivatives in polymer composites based on thermoset resins, which can be used as eco-friendly high-performance materials. Eugenol has been successfully used in the production of epoxy composites as a component of coupling agents, epoxy monomers, flame retardants, curing agents, and modifiers. In addition, it reduced the negative impact of thermoset composites on the environment and, in some cases, enabled their biodegradation. Eugenol-based silane coupling agent improved the properties of natural filler epoxy composites. Moreover, eugenol flame retardant had a positive effect on the fire resistance of the epoxy resin. In turn, eugenol glycidyl ether (GE) was used as a diluent of epoxy ester resins during the vacuum infusion process of epoxy composites with the glass fiber. Eugenol-based epoxy resin was used to make composites with carbon fiber with enhanced thermomechanical properties. Likewise, resins such as bismaleimide resin, phthalonitrile resin, and palm oil-based resin have been used for the production of composites with eugenol derivatives.