SYNTHESIS AND CHARACTERIZATION OF POLYESTERS FROM RENEWABLE CARDOL

The preparation and thermal characteristics of new polyesters from cardol, a renewable monomer obtained as a by-product of the cashew industry, are reported. Cardol - a diol component of the natural product cashew nut shell liquid (CNSL) was isolated and reacted with adipoyl chloride and terephthaloyl chloride in a 1: 1 molar ratio in hexane and toluene as solvents at 170 degrees C under nitrogen atmosphere. The cardol based polyesters [poly(cardyl adipate) and poly(cardyl terephthalate)] were produced in good yields of up to 63 and 54%, respectively. The polymers were analysed by FT-IR for functional groups elucidation and by combined thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) for thermal stability. The cardolbased polyesters were thermally stable up to about 400 degrees C. The thermal stability of poly(cardyl terephthalate) was higher than that of poly(cardyl adipate) under similar conditions. All prepared polyesters were insoluble in common laboratory solvents at room temperature.