Effect of supercritical carbon dioxide on ultradispersed polytetrafluoroethylene

Deposition of polymer coating on metallic powder through ball milling: Application to hydrogen storage intermetallics

“…The PTFE and the TiFe/PTFE composite remain stable under the same conditions. A small decrease of the sample mass may be attributed to water desorption from the surface or evaporation of low‐molecular fractions formed during high‐energy grinding of the PTFE . It can be concluded from the tests done that the polymer coating acts like a barrier and it really protects the metallic particles from the oxidation in air even at elevated temperatures.…”

Fractionation of ultradisperse polytetrafluoroethylene in supercritical carbon dioxide and the chemical structures of the fractions

“…It has been proposed that PTFE exists in four different conformations: three helices with different angles and a planar zigzag [24]. In particular, if the helix trans forms into a planar zigzag with higher symmetry D 2h , some bands in the IR spectrum must disappear.…”

“…Coat ing a textile material with a thin polymer film and increasing the roughness of the material can help sur mount the first disadvantage [23]. As to the second disadvantage, on the basis of the TGA data that the mass loss of the polymer occurs in two steps at differ ent rates owing to the presence of fractions with high and low molecular masses [9], we suggested that the fractionation of ultradisperse PTFE in supercritical СО 2 (with consideration for the partial solubility of PTFE in this fluid [24,25]) makes it possible to isolate fractions with different molecular masses for selective use, even at elevated temperatures. Undoubtedly, it was of interest to compare the temperature fraction ation in air and in supercritical СО 2 and to identify the chemical structures of the fractions.…”

Modification of synthetic fiber materials with using fluoro- polymers (review)

“…Ультрадисперсный ПТФЭ с товарным знаком «Форум», разработанный Институтом химии ДВО РАН, является продуктом термогазодинамической деструкции промышленного ПТФЭ [21,22]. Он состо-ит из композиции перфторированных линейных цепей (-CF2-)n со средним числом звеньев более 100 и низкомолекулярной фракции из олигомеров со средним размером порядка [13][14][15][16] звеньев, хорошо растворимой в СК-СО2 [ [23][24][25][26][27].…”