Multiple transitions in atactic 1,2‐polybutadienes observed from dynamic mechanical and dielectric relaxation data

Abstract

AbstractDetailed investigation by dynamic mechanical, dielectric and 13C‐NMR relaxation spectroscopies over a temperature range from −180 to 100°C reveals the multiple transitions in atactic 1,2‐polybutadienes, which are denoted as T11, α, β, γ, and δ in conformity with reducing temperature. The spectroscopic data obtained show that α transition is the glass transition of the samples, β‐and γ‐relaxations are likely to be related to the flexibility of the main chain and the side chain motion, respectively, and δ loss process seems to be associated with the defects and inhomogeneity in structure. T11 transition observed in the dielectric relaxation spectra may be manifested by the abrupt broadening of the resonance peaks in solid‐state 13C‐NMR spectra.