Oxygen-containing polymers, structure

Much research into radiation effects on polymers is done with samples sealed under vacuum. However, polymer materials may, in practical applications, be subjected to irradiation in air. The effect of irradiation is usually substantially different in air, with increased scission at the expense of crosslinking, and the formation of peroxides and other oxygen-containing structures. Diffusion rates control the access of oxygen to radicals produced by the radiation, and at high dose rates, as in electron beams, and with thick samples, the behaviour may be similar to irradiation in vacuum. Surface changes may be quite different from bulk due to the relative availability of oxygen. 

For example, there is considerable interest in the preparation of sulfur-nitrogen polymers that have organic substituents on the sulfur atoms.56 This could help alleviate the intractability problem mentioned, and could also give rise to a series of polymers that parallel the phosphazenes in their structural variability. A series of polymers with S-N backbones of this type has been prepared, but with oxygen atoms as some of the substituents. The basic structure has the repeat unit -RS(=0)(N)- or -FS(=0)(N)-but they have not yet been studied in detail. The fluorine-containing polymer, however, is known to be a tough elastomer which is unaffected by water, acids, or bases up to 100 °C.7... 

The negative FAB SIMS spectra of the fluoropolymers did not contain any particularly useful information. The major peak observed is at M/Z 19 F. Small peaks of one percent intensity or less are observed at M/Z 12 C-, 16 0, 2L, C2-, 31 CF , and 38 F2-. Our experience suggests that negative FAB SIMS appears to be the most useful for the determination of the relative amount of oxygen in the polymer structure since positive SIMS has low sensitivity for oxygen and potential interference from hydrocarbons at M/Z 16. 

Furfural (1), derived from annually renewable agricultural byproducts, is an important industrial chemical manufactured and used throughout the world. It is the feedstock for a number of derivative chemicals generically known as furans -the structural characteristic of which is the five-membered oxygen-containing heterocyclic ring. Furfuryl alcohol (2) is the most important derivative of commerce, where it is used primarily in synthesis of adhesive polymers. 

In this section the identification of various structural features from the measured binding energies of the core level electrons is discussed. Examples have been chosen in the areas of (a) plasma polymerization of fluorinated materials and (b) surface oxidation of polymers, to encompass both fluorine-containing and oxygen-containing systems. 

In addition to the relatively simple oxygen-containing structural feature already discussed, to be able to obtain a complete picture of an oxidized polymer surface it is also... 

Therefore, we hope to discuss the polymerization mechanism and polymerizability of bicyclic compounds containing oxygen atoms and their relation to the monomer and polymer structures. Finally, some biomedical application of polymers will be mentioned. 

The structure dependency of the etching rate is enhanced in chemically reactive luminous gas, but the nature of dependence remains the same. Plasma-sensitive structures such as -O- in the backbone of a polymer- and oxygen-containing pendant group play a dominant role. It is important to note that LCVT, chemical etching of polymers by non-polymer-forming gas plasma, can be well described by the same discharge power parameter for LCVD, which is WjFM. 

Figure 12.6 Dependence of polymer deposition rate on molecular weight of monomer. Group I (O)- triple-bond-containing, aromatic, and heteroaromatic compounds group II ( ) double-bond-containing and cyclic compounds group III (A) compounds without aforementioned structures group IV (x) oxygen-containing compounds.

---