Vacuum Thermal Degradation of Poly(ethylene oxide)

Abstract

Thermal degradation of poly(ethylene oxide) (PEO) was studied under vacuum conditions. PEO macromolecules degrade predominantly by random chain scission of a backbone with elimination of oligomer fragments. The reactions include the mechanism of radical termination by disproportionation. The eliminated fragments form thin film deposits which have chemical composition close to the original PEO. Activation of the evaporated flux with a glow discharge leads to further fragmentation and recombination of the released species and can be used to tune the properties of the resulting thin films.

Does Cross‐Link Density of PEO‐Like Plasma Polymers Influence their Resistance to Adsorption of Fibrinogen?

“…The depositions were performed on the experimental setup described in the previous publications 4, 5. Poly(ethylene oxide) (Sigma‐Aldrich, M = 1 500 g · mol −1 ) was loaded into a copper crucible placed above an r.f.…”

“…Therefore, the monomers are low‐molar‐mass volatile substances. Nevertheless, it has been recently shown that vacuum thermal degradation of conventional polymers can be utilized as a source of higher molar mass species 4, 5. In this case, the polymer is heated under rarefied inert atmosphere to a temperature at which thermal decomposition of macromolecular chains occurs.…”

“…Naturally, the chemical composition of such ensemble is governed by degradation mechanisms of a particular polymer and can be generally very different from the original. From this point of view, poly(ethylene oxide) (PEO) is remarkable as it decomposes thermally into a mixture of linear oligomers of chemical composition very close to conventional PEO 4. Although low‐molar‐mass fragments are also released, they are effectively removed by the pumping system and do not participate in the film formation.…”

“…Although low‐molar‐mass fragments are also released, they are effectively removed by the pumping system and do not participate in the film formation. Thus, the flux of emitted PEO oligomers is analogous to the flow of vapors of organic precursors, except that it does not consist of a single type species but is rather characterized by a distribution of molar masses, with the average exceeding 1 000 g · mol −1 4, 5. Oligomers released as a result of vacuum thermal degradation of PEO can condense on the substrate to form a polymeric film.…”

The thickness dependence of dielectric properties in the plasma polymer thin films

“…Furthermore, still it draws attention nowadays. [15][16][17][18][19][20]. In fact, It can be said that this method opens a new application area in material synthesis.…”