INTERPOLYMER ASSOCIATION BETWEEN POLY(VINYLPYRIDINES) AND POLY(MONO-N-ALKYL ITACONATES) - EFFECT OF THE N-ALKYL SUBSTITUENT

The binary polymeric systems formed by some poly(mono-n-alkyl itaconat es) and poly(2-vinylpyridine) or poly(4-vinylpyridine) are studied. De pending on the solvent, two different types of material have been synt hesized. On the one hand, using methanol as common solvent, we have ob tained solid polymer-polymer complexes the composition of which is det ermined by the initial mixing conditions. On the other hand, pyridine avoids the complexation process, allowing to obtain a true solution of both polymers and, therefore, a solid polymer blend of known composit ion by solvent casting. Yields of the complexation and stoichiometries of the polymer-polymer complexes have been analysed. In this way, a f avoured composition in the range from 3:2 to 1:1 for the mole ratio (r eferring to repeating units) ratio poly(mono-n-alkyl itaconate): poly( vinylpyridine) was observed depending on the poly-(mono-n-alkyl itacon ate used). Differential Scanning Calorimetry and thermogravimetry have been employed to study the thermal behaviour of complexes and blends. Viscometry measurements have been performed to analyse the interactio ns in solution. One of the aims of this work has been to analyse the e ffect of the side group of the poly-(mono-n-alkyl itaconate) in the mi xing process as well as in the characteristics of the final products. In this way, higher complexation yields have been obtained using poly- (mono-n-alkyl itaconates) with longer n-alkyl side groups due to the a dditional stabilisation by solvophobic interactions. On the other hand , the poly(mono-n-alkyl itaconates) with longer n-alkyl groups form po lymer-polymer complexes with a higher proportion of poly(4-vinylpyridi ne), presumably due to their slower kinetics of complexation.