Crystallization Behavior of Poly(3,3-bis(Ethoxymethyl) Oxetane) and Poly(3,3-bis(Azidomethyl) Oxetane)

摘要

Two crystal modifications have been found for poly (3,3-bis(ethoxymethyl) oxetane), poly(BEMO), by wide-angle x-ray powder diffraction and differential scanning calorimetry while only one modification has been found for poly(3,3-bis(azido methyl) oxetane), poly(BAMO). Melting temperatures for the two polymers were nearly the same, varying from about 70 deg C to about 90 deg C depending on the thermal treatment; higher crystallization temperatures resulted in higher melting temperatures. The equilibrium melting temperature, T sub m, was found to be 125 deg C and 128 deg C for poly(BEMO) and poly(BAMO), respectively, using the Hoffman-Weeks extrapolation procedure. Measurement of the melting point depression of poly(BEMO) and poly(BAMO) in di-butyl phthalate yielded enthalpy of fusion values of 2.25 kcal/mole and 12.8 kcal/mole, respectively. The percent crystallinity for poly(BEMO) and poly(BAMO), respectively was calculated to be 55-60% and 13-30% based on DSC and x-ray analysis.