Butyl rubber is a synthetic rubber, a copolymer of isobutylene with isoprene. The abbreviation IIR stands for isobutylene isoprene rubber. Polyisobutylene, also known as PIB or polyisobutene, (C 4 H 8) n, is the homopolymer of isobutylene, or 2-methyl-1-propene, on which butyl rubber is based.Butyl rubber is produced by polymerization of about 98% of isobutylene with about 2% of isoprene.Structurally, polyisobutylene resembles polypropylene, having two methyl groups substituted on every other carbon atom.utyl rubber has excellent impermeability, and the long polyisobutylene segments of its polymer chains give it good flex properties. The formula for PIB is: â(âCH 2 âC(CH 3) 2 â) n â. The formula for IIR is:
Biot wrote two main articles on breathing patterns. One large exploratory work focused on his observations on CheyneâStokes breathing.3 4 In each paper, he described patients who were admitted to the Hotel Dieu Hospital with CheyneâStokes Ë respiration, his major interest.
During the process of respiration, excess carbon dioxide is removed from the body and this is replaced by atmospheric oxygen; however there is still some level of carbon dioxide that remains in the blood. Having a low level of carbon dioxide in the blood or a high level of carbon dioxide in the blood will greatly affect some of the functioning in the body. These functions are associated to those of the cardiovascular system as well as the systems associated with cellular-based respiration.