A straightforward synthesis of indole-2-carboxylic esters was developed through a ligand-free copper-catalysed condensation/coupling/deformylation cascade process from 2-halo aryl aldehydes or ketones with ethyl isocyanoacetate. The reactions proceeded well for most of the 2-iodo-, bromo-, and chloro-substrates under room temperature or mild conditions.

A series of novel rosin-based siloxane epoxy resins (AESE copolymers) were prepared by the reaction of ethylene glycol diglycidyl ether modified acrylpimaric acid (AP-EGDE) with poly(methylphenylsiloxane). The chemical structures of the produced epoxy resins were determined by FTIR, 1H-NMR, 13C-NMR, and epoxy equivalent weight (EEW) test. After modification, the tensile strengths of AESE (20–40) are slightly lower than that of AP-EGDE; however their breaking elongations are higher than that of AP-EGDE remarkably. TGA results reveal that the thermal stability of AESE serials is better than that of AP-EGDE due to the formation of a protective residue. The char residue of AESE increases at 700 °C with its silicon content increases. Nevertheless, there is a peak LOI value for AESE when its silicon content is 30%. Moreover, the chemical structures of char at the end of the LOI test were analyzed by FTIR. The results confirmed the formation of the protective residue.

Triglycidyl ester FPAE and glycidyl ethers FPEG1, FPEG2, and FPEG3, listed in order of increasing flexible chain amounts, were obtained from rosin and characterized by 1H nuclear mangetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopy. The effects of a harder dose on cured resin properties were studied by determining the tensile strength and water absorption. The results indicated that the optimum harder dose of the FPEG system was higher than the stoichiometric ratio. The effects of flexible chains on cured resin properties were studied by tensile strength characterization, differential scanning calorimetry, thermogravimetric analysis, water absorption, and acetone absorption. The results showed that the cured resin FPAE1C exhibited the best thermal properties, water resistance, and acetone resistance. FPAEC did not display the best tensile properties, because of its brittleness, but the tensile strength was improved by introducing the flexible chain. Moreover, FPAE, FPEG1, and FPEG2 displayed tensile strength similar to that of petrochemical E44, and FPAE exhibited a high glass-transition temperature (T g), compared to E44.