Mechanical and dielectric relaxations of poly(hydroxy ethers): 1. Low-temperature relaxations

Abstract Mechanisms for the low-temperature relaxations were investigated for poly(hydroxy ethers) prepared by the polyaddition reaction of diglycidyl ethers with diphenols. Two relaxations, denoted β and β′, are observed at −70 and +40°C (for a frequency of ∼ 1 Hz), respectively. It is revealed by comparing the mechanical relaxation with the dielectric relaxation that the β relaxation is a complex relaxation, that is, the overlap of the relaxation of hydroxy ether segment with that of other parts in the polymer chain, and that the β′ relaxation is due to the motion of the phenylene group in the polymer chain. In the acetylated poly(hydroxy ethers), the relaxation of the hydroxy ether segment disappears and a new relaxation due to the motion of the acetylated segment appears near 0°C. This new relaxation is superimposed upon the β′ relaxation.