Part I. On the physical characterization of ethene/propene/CO terpolymers:effect of composition

A series of ethene/propene/CO terpolymers (PEPCO) with different ethene/CO (ECO) contents has been prepared and physically characterized. The ECO cont ent varies between 0 and 80 wt%. Dielectric investigations have been carrie d out over wide ranges of frequency (10(-1)-10(6) Hz) and temperature (-65 to 60 degrees C). In addition, differential scanning calorimetry (DSC) and stress-strain measurements have been done. The dielectric results showed th at all samples exhibit three or more relaxations, namely; local, glass and high-temperature process. The relaxation strength of the local process is f ound to increase with increasing the ECO contents and is attributed to the ECO blocks. DSC showed that the glass transition temperature decreases with increasing ECO content and varies between 3 and 23 degrees C. The composit ion dependence of the glass temperature, T-g, follows a Fox behavior. In ad dition, DSC measurements showed an endothermic process with multiple peaks in the range 30-150 degrees C. The heat of melting increases slightly with increasing ECO content. The stress-strain behavior is similar to thermoplas tic rubber for samples with ECO contents lower than 50 wt%. (C) 2000 Elsevi er Science Ltd. All rights reserved.