Thermogravimetric analysis of poly(epsilon-caprolactam) and poly[(epsilon-caprolactam)-co-(epsilon-caprolactone)] polymers

The thermal degradation of poly(epsilon -caprolactam) and its copolymers wi th epsilon -caprolactone has been studied by high-resolution thermogravimet ric analysis (TGA), followed by the analysis of evolved gas via a simultane ous coupling to Fourier transform infrared spectrometry (FTIR) and mass spe ctrometry (MS). Poly(E-caprolactam) and poly(epsilon -caprolactone) polymer s are, respectively, degraded at different temperatures, rendering this stu dy to be particularly useful in determining the structure of their copolyme rs, i.e. random or blocky-like copolymers. The poly[(epsilon -caprolactam)- co-(epsilon -caprolactone)] polymers have been synthesized in bulk by anion ic ring-opening copolymerization promoted by epsilon -caprolactammagnesium bromide in a temperature range from 120 to 180 degreesC. A multi-step degra dation was observed by TGA, and characterization of the evolved gas by FTIR and MS gives credit to some blocky-like enchainment of the comonomers, Thi s assignation has been further confirmed by TGA directly performed on blend s of poly(epsilon -caprolactam) and poly(epsilon -caprolactone) as obtained by solvent casting. (C) 2001 Elsevier Science Ltd. All rights reserved.