Polymorphism in nylon-11 : Characterization using HTWAXS and HTFTIR

Nylon-11 was crystallized into different crystalline phases by appropriate methods. The α phase was obtained by precipitating nylon-11 in 1,4-butanediol. The melt crystallized sample at 175 °C gave pseudohexagonal phase. The γ phase was obtained by casting nylon-11 in trifluroacetic acid (TFA). The change in the structure was monitored in situ by high temperature wide-angle X-ray scattering (HTWAXS) and high temperature Fourier transform infrared spectroscopy (HTFTIR). The studies have shown that nylon-11 is one of the few nylons that exhibit extensive degree of polymorphism. HTFTIR studies revealed, apart from the conformational differences between various phases of nylon-11, some information on the formation of γ phase.

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