Abstract
DTA, TG, and TMA curves of commercial Kevlar® 49 and Nomex® fibers have been used to assess their behavior at high temperatures. The fibers lost absorbed water around 100°C, and a glass transition was reflected in the DTA and TMA curves in the region of 300°C. Difficulties in the interpretation of DTA and TMA curves in the glass-transition region and in the assignments of Tv‘s for these high-performance fibers are discussed. Whereas Kevlar 49 showed both a crystalline melting point (560°C) and a sharp endothermal thermal decomposition (590°C), Nomex showed only the latter (440°C) and no evidence of melting from the DTA curves. The endothermal decomposition peaks apparently correspond to “polymer melt temperatures” reported for related materials, and correlate well with the TG and TMA features. During thermal analysis of Kevlar 49, oxidation occurs more readily than thermal decomposition, but the latter predominates for Nomex. Differences between dyed and undyed Nomex were due to differences in yarn constitution.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
