Differential thermal analysis of synthetic fibers

Abstract

The application of differential thermal analysis (DTA) for the characterization and the investigation of the thermal degradation of synthetic textile fibers, to include polyester, nylon 6, propropylene, and polytetrafluoroethylene fibers, has been studied. The temperature range was from 50 to 650°C. using laboratory‐built DTA apparatus. Experimental considerations and techniques are discussed and such variables as sample preparation, size, cell packing, atmosphere control, and heating rate have been investigated. The conventional technique of grinding or milling DTA samples is shown to cause significant changes in certain samples, particularly in undrawn fibers. The control of sample atmosphere by dynamic gas flow through the sample cell gave peaks that were generally sharper and larger than those found when control was by gas diffusion. Data are given on the various low temperature transitions found in such fibers. Significant differences in low temperature transitions were observed between polypropylene fiber and the bulk polymer as well as between drawn and undrawn nylon 6 fibers. The interpretation of the DTA curves for the decomposition and other reactions at elevated temperatures is discussed. Nylon 6 and polypropylene showed only endothermic reactions indicative of depolymerization processes whereas other fibers showed both endothermic and exothermic reactions in the decomposition range.

Evaluation of polyolefin-based macroporous separators for high temperature Li-ion batteries

“…5A left). The thermal degradation of pristine Celgard 1 2400, from roughly 290 C, could be ascribed to its depolymerization to, at least partly, monomer [32,33], since the ceiling temperature of PP is close to 300 C, although bond cleavage is not discarded. This thermal degradation of polypropylene based separators does neither affect the Li-ion battery operation nor limit exothermal runaway.…”

Synthesis of perfluoro-t-butyl trifluorovinyl ether and its copolymerization with TFE

“…1. The decomposition temperature of the copolymer synthesized under the above condition was lower than that of Teflon 1 (525 8C) [39] and Teflon 1 PFA (ca. 480 8C) [40], which provided good evidence for the copolymerization.…”

Ultra high density carbon fiber derived from isotactic polypropylene fiber without skin‐core structure

“…Figure 1B showed the DSC curves of PP fibers sulfonated at 120°C. The exothermic peak at 175°C gradually disappeared due to melting of the crystalline region, while the exothermic peak at 158°C continuously to rise until 2 h due to the stress induced orientation of the crystalline region of PP fibers 32 . Since contraction of the fibers in the fixed frame was inevitable during sulfonation, resulting in internal stress inside the fiber.…”