Synthesis and biocidal efficacy of self‐spreading polydimethylsiloxane oligomers possessing oxyethylene‐functionalized quaternary ammoniums

Abstract

ABSTRACT:In an effort to develop a more versatile creeping biocide that is capable of self-spreading and selfdecontaminating of pathogenic bacteria, we report the development of two new homologous series of hybrid PDMS molecules. These oligomers were synthesized with terminal quaternary ammonium functionalities bearing variable length oxyethylene moieties. It is shown that the ionic interaction of the ammonium groups with the surface onto which it spreads can be tempered by the oxyethylene segments through close association of the polar chains with the cationic centers within the hydrophobic PDMS environment, thereby promoting self-spreading of the molecule. Once the compounds spread to a humid environment, the oxyethylene chains ''blossom'' and subsequently expose the biocidal centers, at which point, function as broad spectrum versatile antimicrobials. While biological evaluation showed antimicrobial activity against both Gram-positive and Gram-negative bacteria for all samples, one series was found to be much more effective due to lower steric hindrance surrounding the biocidal cationic termini. However, this increased exposure of the cationic center also altered the physical properties of the compounds except those isolated as a waxy solid. Self-spreading abilities with increasing oxyethylene chain length correlating to a decreasing spread rate. The decontaminating ability of the two most active compounds was demonstrated by allowing samples to spread to pools of water contaminated with S. aureus, yielding log reductions as high as 5.7 in less than two hours without external influ-

Molecular level studies of polymer behaviors at the water interface using sum frequency generation vibrational spectroscopy

“…78,79 Incorporating biocides into PDMS may lead to polymer coatings which can have both antifouling and fouling-release characteristics. 80,81 SFG has been used to characterize the surfaces of PDMS materials with various quaternary ammonium salts (QAS) incorporated into the polymer. 20,21 In addition, the effects of bulk biocide concentration and the tethered QAS chain length on the surface structure of PDMS incorporated with QAS were investigated.…”

Silicone containing copolymers: Synthesis, properties and applications

“…Three different microphase morphologies were observed as a function of the block lengths and copolymer composition(236). PDMS-PEO copolymers containing quaternary ammonium groups were shown to possess biocidal activity(237).Hydrophobic drug carrying polymeric nanovesicles were also prepared from PDMS-PEO copolymers by using THF/water mixtures. Vesicle size was controlled by copolymer concentrations and THF/water ratio(238).…”

Synthesis and characterization of a polyurethane ionene/zinc chloride complex with antibacterial properties

“…Quaternary ammonium cation also showed antibacterial activity in some cases as mentioned above. 12,21 In order to incorporate ZnCl 2 into polymer matrix, we synthesized a quaternary ammonium salts diol and mixed it with ZnCl 2 to form a complex chain-extender. ZnCl 2 can be easily incorporated into polyurethane matrix by polymerization of polyols, diisocyanates, and the complex chain-extender.…”

“…20 One of most classical and effective AB agents should be quaternary ammonium salts (QAS), mainly due to the fact that it is a broad-spectrum bactericide and can be easily tailed for desired functionality through traditional chemical synthesis. [21][22][23] To introduce the QAS into polymers, a common way is to synthesize cationic monomers with quaternary ammonium groups on the pendant side, and then polymerize them. 24 QAS group can also be gained by quaternization of amine aer polymerization.…”