Synthesis and characterization of polymers from cashewnut shell liquid: a renewable resource: V. Synthesis of copolyester

A novel copolyester was synthesized by solution polycondensation of terephthaloyl chloride with 4-[(4-hydroxy-2-pentadecenylphenyl)diazenyl] phenol (HPPDP) and 1,4-butane diol. The monomer (HPPDP) has been synthesized from 3-pentadecenyl phenol, a renewable resource and a by-product of the cashew industry characterized earlier . The copolyester was characterized through elemental analysis, 1H-NMR, IR, and UV spectroscopy. Dilute solution viscosity of its solution was also determined by viscometry. The intrinsic viscosity [η] was 0.98 dl/gm. The melting temperatures of the copolyester were 63 and 127°C as observed from Differential Scanning Calorimetric (DSC) studies. Thermogravimetric analysis show that degradation commences at 290°C in nitrogen atmosphere. Wide-angle X-ray diffraction study of the copolyester indicates absence of any crystallinity, whereas DSC studies indicate the presence of two melting peaks. Thus, it is presumed that the copolyester has short range crystallinity.