Thermal properties of polyvinyl alcohol fibres in the presence of a phosphorus-containing catalyst

Abstract

A. V. Tolkachev, T. V. Druzhinina, and L. A. Nazar'ina UDC 677.494.745.32.021.125.56 The thermal properties of polyvinyl alcohol in the presence of phosphorous-containing and other inorganic compounds were investigated. The catalytic role of a phosphorus-containing fireproofing compounddiammonium phosphate --in thermooxidative decomposition of PVA was revealed. It was found that dehydration of PVA is intensified, the activation energy of decomposition of PVA increases, and its cokeforming power also increases in the presence of (NH4)2HPO 4.

Poly (vinyl alcohol) based carbon nanofibers as freestanding anodes for lithium‐ion batteries

“…Although conventional CNF precursor PAN polymer needs oxidative stabilization, linear PVA chains must be stabilized via special suitable processes to suppress the thermal degradation. Stabilization of PVA under HCl, 21 H 2 SO 4 , 22 vapor or acidic impregnation with different salts, 23 very slow thermal dehydration, 15 and addition of catalyst and iodination 18,24,25 was reported in the literature. Compared to other methods, PVA stabilization under iodine vapor is a one‐step facile stabilization approach at low temperatures, which provides a higher carbon yield 18,25 …”

Realizing Ultrapurified Poly(vinyl alcohol) with High Insulation and Transparency by Ecofriendly Supercritical Assisted Elimination of Sodium-Associated Impurities

“…According to the study on dehydration of poly(vinyl alcohol), there is significant quality reduction at ∼250 °C in the thermogravimetric diagram of PVA. 25 Another conventional approach is to select a scavenger or chelation agent to remove metallic impurities from the polymers in solvent dissolution. 26 Whereas, such processes are commonly laborious and wasteful, not to mention their corrosive and hazardous reagents, preventing the fabrication of biocompatible and ecofriendly devices.…”

“…For the heating evaporation method, the boiling point (above 400 °C) of sodium acetate is much higher than the highest temperature of PVA heat-resistant (above 250 °C), henceforth destabilizing the molecular structure of PVA before sodium acetate reaches its evaporation threshold. According to the study on dehydration of poly­(vinyl alcohol), there is significant quality reduction at ∼250 °C in the thermogravimetric diagram of PVA . Another conventional approach is to select a scavenger or chelation agent to remove metallic impurities from the polymers in solvent dissolution .…”

Effect of ammonium orthophosphate on thermochemical transformations of hydroxyl-containing polymers

“…[1,2]. The specific features, as well as the complexity of the technology for manufacturing carbon fibre materials (CFM), consist of conducting rigorously controlled pyrolysis of an organic polymer with elevation of the temperature by steps in the range from 200 to 2500°C to eliminate heteroatoms from the polymer and retain carbon to the maximum, and in conditions of high-temperature treatment of the polymer, including carbon.Phosphorus-containing compounds are an effective pyrolytic additive in production of CFM for such carbonized polymers as hydrated cellulose (HC) and polyvinyl alcohol (PVA) [3][4][5]. On this basis, in studying the thermochemical transformations of these polymers, we selected ammonium orthophosphate, not previously used for these purposes, as the pyrolytic additive.…”

“…Phosphorus-containing compounds are an effective pyrolytic additive in production of CFM for such carbonized polymers as hydrated cellulose (HC) and polyvinyl alcohol (PVA) [3][4][5]. On this basis, in studying the thermochemical transformations of these polymers, we selected ammonium orthophosphate, not previously used for these purposes, as the pyrolytic additive.…”