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This article describes the use of microwave irradiation in the synthesis of bis(cyclo carbonate) compounds (BCCs) in bulk (without solvent) from carbon dioxide capture using an epoxidized compound—a commercial epoxy resin—and compares this process to the conventional method. CO2 cycloaddition to epoxides is an ecological and efficient method for the formation of bis(cyclic carbonates). Moreover, the introduction of gas into the reaction mixture was carried out at atmospheric pressure with a controlled flow rate, which is advantageous from an economic point of view. Progressive structural changes and the presence of characteristic chemical groups were monitored using attenuated total reflectance infrared spectroscopy with Fourier transform. The obtained crude products were purified to obtain three fractions, which were subjected to detailed structural analysis using FT-IR and 13CNMR. The formation of the main product with two cyclic carbonates was confirmed. The presence of monomers, dimers and trimers in individual fractions as well as their thermal stability were determined, and the molecular masses in individual fractions were determined using gel permeation chromatography (GPC). [ABSTRACT FROM AUTHOR]

In contemporary developments across automotive, aerospace, and military industries, there is an ever-growing demand for lightweight and robust polymer composites. In this study, a ductile epoxy resin, carbon nanotubes (CNTs), cellulose nanofibers (CNFs), and silica nanoparticles were used to fabricate nano-fillers/epoxy composites and nano-fillers/silk fibers/epoxy hybrid composites through solution casting and hot pressing. Their mechanical properties and thermal characteristics were analyzed and compared, which show that: these nano-fillers can dramatically enhance the strength and stiffness of the ductile epoxy resin; however, this is achieved at the expense of its toughness and extensibility. CNT/silk fiber/epoxy hybrid composite has the highest tensile strength (81.10 MPa), Young's modulus (3.76 GPa) and impact strength (103.7 kJ/m2), while the CNFs-reinforced one exhibits the highest breaking energy (9.96 MJ/m3). These nano-fillers almost do not affect the thermal stability of the epoxy resin and silk fiber composites. In addition, the fracture modes of their reinforced composites were revealed by macroscopic and microscopic observations. • Reveal how different nano-fillers affect the mechanical behaviors of ductile polymer matrix. • Explore the optimal content of these nano-fillers in the polymer matrix. • Indicate nano-fillers do not affect the thermal stability of their reinforced composites. • Elucidate the composites' fracture modes introduced by silk fibers and different nano-fillers. [ABSTRACT FROM AUTHOR]