We have used FT-IR spectra to explain the effects of hydrogen bonding between chitosan and polycaprolactam (PA6). A dynamic mechanical analysis study suggested that the optimum chitosan and PA6 miscibility under the conditions of this experiment were obtained at a blending ratio of 40:60. We studied the thermal degradation of chitosan blended with PA6 (chitosan/PA6) by thermogravimetric analysis and kinetic analysis (by the Ozawa method). Dry chitosan and PA6 exhibited a single stage of thermal degradation and chitosan/PA6 blends having >20 wt% PA6 exhibited at least two stages of degradation. In chitosan/PA6 blends, chitosan underwent the first stage of thermal degradation; the second stage proceeded at a temperature lower than that of PA6, because the decomposition product of chitosan accelerated the degradation of PA6. The activation energies of the blends were between 130 and 165 kJ/mol, which are also lower than that of PA6.

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Imide-containing siloxane-urethane copolymers (I-PU copolymers) were synthesized from 4,4'-diphenylmethane diisocyanate (MDI), OH-terminated polydimethylsiloxane (PDMS) and pyromellitic dianhydride (PMDA). The hard segment consisted of urethane and imide segments and the soft segment was PDMS. The DSC of I-PU copolymers suggests that they had a high degree of phase separation in their low hard segment contents and phase mixing in high hard segment contents. DMA indicates similar phase behaviour and shows that incorporating imide segments into the copolymers can maintain the high modulus at high temperature. The progress of degradation of I-PU copolymers was determined by TGA and standard kinetics methods and there were three stages at around 250~425 °C, 425~560 °C and 560~700 °C, respectively. The first stage was dominated by the hard-segment structure and content. Incorporating imide segments into PU raises the characteristic temperatures of degradation in the first stage. The second stage resulted from the degradation of the PDMS soft segment to form oligomers by the interchange reaction. The degradation of the imide segment leads to the third stages because the maximum rate of degradation in DTG curves increases with the imide content.