The cardanol formaldehyde resin (CFR) has been synthesized by the condensation of cardanol with formaldehyde (ratio of 1:0.7) in the presence of oxalic acid catalyst. Synthesized CFR was epoxidized using epichlorohydrin (ECH) with 1:10 molar ratio. Cardanol was also directly epoxidized using ECH with the above-mentioned ratio. Synthesized resins have been characterized by Fourier-transform infrared and nuclear magnetic resonance spectroscopic analyses. Thermal properties have been studied by thermogravimetric analysis. Decomposition kinetics have been studied by various kinetic models of the synthesized compounds. In the present study, Horowitz-Metzger, Broido and Coats-Redfern models have been used to calculate the activation energy (E a ), pre-exponential factor (A) and rate constant (K). E a calculated from all the three models mentioned above was close to each other.

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MAHADEVA NATARAJAN and ETALO A. SECCO. Can. J. Chem. 53,1542 (1975. . , Electrical conductivity measurements have been made on single crystals of undoped potassium sulfate and on single crystals of K2S04 doped with divalent ions, viz. MgZ+, Zn2+, Cu2+, and MnZ+. The presence of the divalent ion increases the cation migration energy. The lower defect formation energy is attributed to the lower symmetry of K2S04 relative to the high symmetry cubic systems previously studied.The presence of the dopants and dopant concentration, i.e. Cu2+, show varying effects on the magnitude and nature of the conductivity discontinuity at the orthorhombic-hexagonal phase transition temperature. The phenomenon of "pretransition", 350 to 425 "C, is observed in both pure and doped crystals. Preannealing the crystal contributes to interesting behavior on all the crystals studied. The G-T behavior of K2S04 crystal doped with radioactive "Zn, however, exhibits a simpler linear dependence and the absence of "pretransition" anomaly. MAHADEVA NATARAJAN et ETALO