wherein R may be any suitable substituent as defined above and R??? may be an alkyl comprising from about 2 to about 25 carbon atoms, for example from about 8 to about 16, or an aryl comprising about 2 to about 25 carbon atoms, for example from about 8 to about 16 such as phenyl, benzyl, methyl, ethyl propyl and the like; and n may be a number of segments of from about 10 to about 1,000, and for e