Solid State NMR Studies of Polymer Phase Transitions

Variable temperature, high resolution solid state NMR has been used to study the phase transitions observed in several polymers. The strain induced alpha to beta crystal-crystal transition in poly(butylene terephthalate) (PBT), the thermally induced crystal (I) - crystal (II) transition in trans- 1,4-poly- butadiene (TPBD), the thermochromic blue to red phase transitions in polydiacetylenes (PDA), and the thermotropic crystal to liquid crystal phase transition in the polyphosphazene, bis-4-ethylphenoxy, (PBEPP) were each observed in sup 13 C NMR (sup P NMR was also employed for PBEPP).