Biocidal moieties

The activity mechanism of macromolecular biocides has not been fully explained [105]. Most macromolecular biocide systems studied contain BujSn-groups, fixed by hydrolyzable (amide or ester) or nonhydrolyzable bonds. The former are of advantage in sea applications, where the biocidal moiety BujSnOH can be released. 

Polyesters obtained by interfacial polycondensation of aliphatic and aromatic diacids with dialkyl lead dichloride or dialkyl stannum dichloride possess biocide properties [105]. Ferrocene moieties may be also incorporated. 

The preparation of an antimicrobial nylon 66 material by covalent bonding to biocidal cyclic N-chloramine moieties, including hydantoins, oxazolidinones, and imidazolidinones and its properties are considered. These cyclic materials were stable over at least 3 months dry storage, and after loss of activity by reaction with reducing Na thiosulphate, the activity was easily restored by exposure to free chlorine. Biocidal swatch tests showed that nylon fabrics containing N-chlorinated hydantoin functional groups produced a 7.2 log decrease in Staphylococcus aureus and a log 7.1 decrease in Escherichia coli after a contact time of only 10 minutes. The antimicrobial nylon should have many applications, e.g. in clothing, sutures, carpets, bmshes, etc. 

The synthesis and biocidal efficacies of two PEG-N-halamine polymers were studied. The N-halamines were classified as dichlorohydantoins and chloroimidazolidin-4-ones, which were attached to a methoxy-PEG terminated amine. A1000 ppm solution of each N-halamine polymer was prepared in water and it was demonstrated that Staphylococcus aureus was inactivated when it was in contact with these polymeric solutions for ten minutes. The stability of these solutions was determined over prolonged periods of time, as well as the biocidal efficacies. These polymeric materials showed commercial potential as surface active biocides if the PEG moiety could be anchored to a srrrface. 22 refs. 

SEM images show that silicone has filled and sealed the inter-monofilament pores and voids and indicates that the PEG silicone surfactants coating the fabrics were decomposed after plasma treadnent. The cleaved products coating the nylon fabric appear to be distributed very uniformly. This phenomenon is consistent with the results of the contact angle measuranents cleavage of the prepared surfactants leads to water-insoluble silanol moieties and two water-soluble products this process imparts excellent water repellency to the nylon fabric. Zhang et al. (2003) determined antibacterial properties qualitatively through measurements of areas from which S. aureus and K. pneumonia have been eradicated. The silicone coat at the eradicated area is not transparent. Biocidal treatments with both the silicone and PEG 2000 silicone surfactants improved the antibacterial properties of the nylon fabrics. The results we obtained before and alter plasma treatment were similar, especially for S. aureus. Thus, the sample treated with PEG 2000 silicone retained its antibacterial activity and water repellency after plasma treatment (Lin et al., 2006). 

A very recent contribution to materials based on ricinoleic acid [128] revived two main aspects. The first was a search for optimum conditions related to its homopolymerisation and copolymerisation with butylene succinate. This was attained by using titanium tetrabutoxide at >200 °C to yield products with high molecular weight. Secondly, these materials displayed high biocidal activity, which was enhanced further by appending imidazolium moieties to their macromolecules. 

Wood can be modified by treating with orgaific biocides which have low solubility in water and their organic solution can be dispersed in water using surfactants to stabilize a mostly aqueous liquid-in-organic liquid emulsion. Controlled release formulations of antifouling moieties have been used for the protection of wood against... 

Thamizharasi et al. started with sulfamethoxazole and introduced me-thaciylic, aciylic, and maleimide groups. The resulting polymers revealed in some cases even better activities than the low molecular weight monomers. Similar to biocide-releasing polymers, there is the opportunity to use antibiotics instead of biocides. Moon et al. prepared an aciyl monomer containing a norfloxacin moiety. This polymer was blended with other common synthetic polymers. These samples reduced the viable cell number of microbial cells in shake flask tests. ... 

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