Biocidal polymers active by contact. I. Synthesis of polybutadiene with pendant quaternary ammonium groups

Hydroxytelechelic polybutadienes carrying covalently bound quaternary ammonium salts were successfully synthesized in three steps. The first one was the preparation of 1-(N, N-dimethylaminopropyl) 1,1,3,3-tetramethyldisiloxane (M′₂A) by hydrosilylation. The addition occurred mainly in the terminal position of the double bond, but isomers were formed in small proportion (an isomer resulting from an inverse addition and an isomer resulting from an isomerization of the double bond). The proportion of these isomers increased with the concentration of catalyst (H₂PtCl₆). Similar results were obtained with a Pt (0)-di-vinyltetramethyldisiloxane complex (Pt,DVDS). The second step was the grafting of M′₂A onto the 1,2-units of a hydroxytelechelic polybutadiene by hydrosilylation. The yield of the reaction was higher than 90% and the OH functionality decreased slightly. Here again, different platinum catalysts were compared: initial rates were higher with Pt,DVDS, but the final yields were better with H₂PtCl₆. The last step was the quaternization of the pendant tertiary amino groups in methanol with alkyl bromides from C₈H₁₇Br to C₁₆H₃₃Br. The yield of the reaction was higher than 90% and the OH functionality was not modified. © 1993 John Wiley & Sons, Inc.