Statistical and block all‐siloxane copolymers containing quaternary ammonium salt (QAS) groups with biocidal activity as lateral substituents were synthesized as models for the study of the effect of the arrangement of the QAS groups in the copolymer chain on their antimicrobial activity. The bioactive siloxane unit was [3‐n‐octyldimethylammoniopropyl]methylsiloxane, and the neutral unit was dimethylsiloxane. The copolymers also contained siloxane units with unreacted precursor 3‐chloropropyl or 3‐bromopropyl groups. A small number of units containing highly hydrophilic 3‐(3‐hydroxypropyl‐dimethylammonio)propyl groups were introduced to increase the solubility of the copolymers in water. The bioactive and bioneutral units were arranged in the polymer chain either in blocks or in statistical order. The block copolymers differed in the number and length of segments. The copolymers were obtained by the quaternization of tertiary amines by chloropropyl or bromopropyl groups attached to polysiloxane chains. The arrangement of the bioactive groups was controlled by the arrangement of the halogenopropyl groups in the bioactive copolymer precursor. All model siloxane copolymers showed high bactericidal activity in a water solution toward the gram‐negative bacteria Escherichia coli and the gram‐positive bacteria Staphylococcus aureus. However, no essential differences in the activities of the copolymers with block and statistical arrangements of units were detected. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2939–2948, 2003

SYNOPSISFunctional polysiloxanes bearing both primary alcohols and quaternary ammonium salts (QAS) as lateral substituents were prepared. The synthesis involves a cohydrosilylation of allylic derivatives (N,N-dimethylallylamine and allyloxytrimethylsilane) with various poly(dimethylsiloxane-co-hydrogenomethylsi1oxane)s. During the quaternization of the tertiary amino groups the alcohol functions are also deprotected. The hydroxyl groups allow the polysiloxane to be incorporated in polyurethane films whereas the QAS impart biocidal properties to the coating. In the case of a QAS bearing a hexadecyl substituent, a very high activity was found against Escherichia coli without any observable diffusion. The mode of action by contact between the solid polymer and the microorganisms was confirmed by the excellent durability of the biocidal power after 1 month of immersion in water.

SYNOPSISFilms of polyurethane were prepared by reaction of hydroxytelechelic polybutadienes carrying covalently bound quaternary ammonium salts with an aliphatic triisocyanate. These coatings exhibited high biocidal activity against Gram-positive and Gram-negative bacteria, yeasts, and moulds. It was found that many parameters controlled the bioactivity such as the time of contact between films and bacteria, the [ NCO] / [ OH] ratio used to prepare the cured polyurethane, the concentration of quaternary ammonium salts in the coating, and the length of the alkyl chain from C8 to CI6 linked to the quaternary nitrogen atom. A secondary phenomenon of diffusion only observed with the shorter alkyl chains ( C8 and Clo) was shown to be due to synthesis residues. After these water-soluble impurities are eliminated, the biocidal activity remains excellent: then it is due only to a contact polymer bacteria. 0 1993 John Wiley & Sons, Inc.

Polysiloxanes with 3-(alkyldimethylammonio)propyl pendant groups were synthesized by quaternization of n-octyldimethylamine or n-dodecyldimethylamine with linear polysiloxanes containing 3-chloropropyl groups and/or 3-bromopropyl groups attached to silicon atoms. The precursor polysiloxanes, poly[(3-chloropropyl)-methylsiloxane] homopolymer and various copolymers containing (3-halogenopropyl)-methylsiloxane and dimethylsiloxane units, were obtained by equilibrium cationic polymerization of linear and cyclic siloxanes with (3-halogenopropyl)methylsiloxane units. The polysiloxanes bearing quaternary ammonium salts (QAS) showed bactericidal activity against bacteria such as Escherichia coli and Aeromonas hydrophila when incorporated in a polysiloxane network. The activity was retained after 66 days of immersion in water. The QAS-containing polysiloxanes are also active in aqueous solution.

SYNOPSISHydroxytelechelic polybutadienes carrying covalently bound quaternary ammonium salts were successfully synthesized in three steps. The first one was the preparation of 1-(N,Ndimethylaminopropyl) 1,1,3,3-tetramethyldisiloxane (MLA) by hydrosilylation. The addition occurred mainly in the terminal position of the double bond, but isomers were formed in small proportion ( a n isomer resulting from an inverse addition and an isomer resulting from a n isomerization of the double bond). The proportion of these isomers increased with the concentration of catalyst ( HzPtCls). Similar results were obtained with a Pt ( 0 ) -divinyltetramethyldisiloxane complex (Pt,DVDS) . The second step was the grafting of M;A 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 HzPtCls. The last step was the quaternization of the pendant tertiary amino groups in methanol with alkyl bromides from COH17Br to CI6&Br. The yield of the reaction was higher than 90% and the OH functionality was not modified.