Novel polythioetherimides bearing azobenzene moieties were synthesized from azobismaleimides and bis-2-mercaptoethylether. Kinetics of trans-cis photoisomerization and of thermal conversion of cis to trans isomeric forms were investigated in both polymer solution and poly(methyl methacrylate) doped films using electronic absorption spectroscopy. Thermal recovery kinetics is well described by a two-exponential relation both in solution and polymer matrix, while that of low molecular weight azobismaleimide fit a first-order equation. The photoinduced cis-trans isomerization by visible light of azobenzene chromophores was examined in solution and in polymer films. The rate of photoinduced recovery was very high for azobismaleimides.

Thermally-reversible epoxy-urethane networks are prepared by the reaction of diamines and diepoxy monomers containing two Diels–Alder adducts. The diepoxy compounds are formed via a Diels–Alder rea...

The paper presents the synthesis and thermal behavior of novel epoxy resins prepared from epoxidized castor oil in the presence of or without trimethylolpropane triglycidyl ether (TMP) crosslinked with 3-hexahydro-4-methylphtalic anhydride (MHHPA) and their comparison with a petroleum-based epoxy resin (MHHPA and TMP). Epoxidized castor oil (ECO) was obtained via in situ epoxidation of castor oil with peroxyacetic acid. The chemical structures of castor oil (CO), ECO, and epoxy matrix were confirmed using FT-IR and ¹H-NMR spectroscopy. The morphological and thermal behavior of the resulting products have been investigated. Compared to petroleum-based resins, castor oil-based ones have a lower T_g. Anyway, the introduction of TMP increases the T_g of the resins containing ECO. The morphological behavior is not significantly influenced by using ECO or by adding TMP in the synthesis of resins. The dielectric properties of epoxy resins have been analyzed as a function of frequency (1 kHz–1 MHz) and temperature (−50 to 200 °C). The water absorption test showed that as T_g increased, the percent mass of water ingress decreased.

New functional epoxy resins were prepared by the reaction of dialyldiglycicylbisphenol A (DADGBPA) with diaminodiphenylmethane. DADGBPA was prepared by reaction of o,o′-diallylbisphenol A with epichlorhydrine. By reaction of functional epoxy resins with bismaleimides, new epoxy-bismaleimide resins with good thermostability were obtained. The thermal properties of epoxy resins and epoxy-bismaleimide resins were determined by DSC and TGA measurements.