Patent ID: 8541531

Claim:
A compound selected from the group consisting of compounds III, IV, V and VI, or a salt thereof, having the formulae: wherein: each of R and R 1 is independently selected from the group consisting of a C 1 -C 8 alkyl and phenyl; R 2 is selected from the group consisting of a straight or a branched chain alkylene, a substituted alkylene, an alkenylene, a substituted alkenylene, an alkynylene, a substituted alkynylene, a cycloalkylene, a substituted cycloalkylene, an aromatic, a substituted aromatic, a heterocyclic, a substituted heterocyclic, a heteroaromatic and a substituted heteroaromatic; R 3 is selected from the group consisting of hydrogen and methyl; R 4 is selected from the group consisting of a straight or a branched chain alkyl, a substituted alkyl, an aromatic and a substituted aromatic; n is an integer having the value between 3 and 500; and m is an integer having the value between 0 and 100.