Opening New Gates for the Modification of PVC or Other PVC Derivatives: Synthetic Strategies for the Covalent Binding of Molecules to PVC

Several synthetic strategies based on the use of substituted aromatic and hetero-aromatic thiols for the covalent binding of modifier compounds to PVC are described. A variety of aliphatic alcohols and amines are linked to the aromatic or heteroaromatic rings via highly active functionalities as the isocyanate, acidchloride, or chlorosulfonyl group, and the three chlorine atoms of trichlorotriazine. The first three pathways lead to protected aromatic disulfides obtaining the substituted aromatic thiols by reduction as a final step of an unprecedented synthetic route. The second approach, in a novel, extremely efficient, and scalable process, uses the particular selectivity of trichlorotriazine to connect aliphatic amines, alcohols, and thiols to the ring and creates the thiol via nucleophilic substitution of a heteroaromatic halogen by thiourea and subsequent hydrolysis. Most of the modifier compounds were linked to the polymer chains with high degrees of anchorage. The presented approaches are highly versatile as different activations of aromatic and heteroaromatic rings are used. Therefore, many types of tailored functional nucleophiles may be anchored to PVC providing non-migrating materials with a broad range of applications and properties.