Polymers formed with oxygenated and/or nitrogenated chemical groups, such as polyethylene glycol (PEG) and polypyrrole (PPy), are studied as biomaterials to be implanted in the central nervous system to reduce possible side effects in the spinal cord after a severe injury. This kind of analysis can be used to modify the synthesis of polymers to increase the participation of the most important chemical states in their biofunctions. The main chemical states on PEG/PPy/I indicate that all atoms in pyrrole rings participate in the polymerization resulting in crosslinked, partially fragmented, and highly oxidized structures. Multiple bonds as C ≡C, C ≡N, C=O, and C=N were found in the copolymers, without belonging to the initial reagents, and were generated by dehydrogenation of intermediate compounds during the polymerization. Iodine appears bonded in the copolymers only at high power of synthesis, mainly as C–I and N–I chemical bonds. The collisions of molecules produced structures with a great variety of chemical states based in the monomers, their combinations, crosslinking, doping, fragmentation, and oxidation at different levels in the plasma environment. An XPS study about the structure of plasma biocopolymers synthesized with resistive radio frequency glow discharges and random combinations of ethylene glycol, pyrrole, and iodine, as a dopant, is presented in this work.

Xps peak