Polymer Bulletin 36, 13 - 18 (t 996) Polymer Bulletin 9 Springer-Verlag 1996 PVC modification with bifunctional thiol compounds H. Reinecke, C. Mijangos Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, E-28006 Madrid, Spain Received: 31 July 1995/Revised version: 14 September 1995/Accepted: 23 September 1995 Summary The chemical modification of PVC with bifunctional thiol compounds is reported, Aliphatic as well as aromatic compounds were tested under different reaction conditions. The modified PVC's were studied by IR and H-NMR. Introduction PVC is one of the most important commercial polymers. However, the purpose of materials based upon PVC is limited due to its inferior thermal and mechanical properties. A way to minimize these shortcomings is to increase the intermolecular force by introducing hydrophilic groups into PVC chains. The introduction of hydrophilic groups would also increase the polarity and change solubility characteristics of PVC and thus open the way to new applications. One possibility to achieve this aim is to make use of the nucleophilic substitution reaction. It is well known (1) that thiol compounds can be used for this purpose due to the high nucleophilicity and low basicity of the sulfur. In previous work we have studied the substitution reaction of PVC with different reagents, especially monofunctional thioderivates in solution and in the melt, either in discontinuous or continuous medium, with two purposes. One was the study of substitution mechanism of the polymer (2-4) and the other to improve polymer properties with the aid of tailor made reagents (5-8). Nevertheless, to find new applications to this polymer, i.e. for membrane uses, other reactants ofbifunctional nature needed to be tested. There have been reported several reactions of PVC with difunctional reagents (9-12) in which it was not possible to separate substituted from crosslinked products. In this paper we describe the modification of PVC with a series of commercial and non- commercial products containing a thiol group and a further functional group. Reaction parameters like temperature, solvent and base were varied to find the optimal conditions.