| Abstract: | Random block copolymers of tetramethylene terephthalate and polytetrahydrofuran (PTHF) were prepared by melt polycondensation. Five different molecular weights of PTHF were used in the polymerizations with up to 30% by weight incorporation. The copolymers so obtained were characterized in terms of their molecular weight by means of endgroup analysis and solution viscometry. Compositions were established by nuclear magnetic resonance spectroscopy. Thermal properties were studied by differential scanning calorimetry and dynamic mechanical methods. Melting and glass transition temperatures are discussed in terms of the structural differences, particularly the effect of polyether composition and block size on chain flexibility. |
