RESUMO
Antimicrobial polymers are an attractive alternative to low molecular weight biocides, because they are non-volatile, chemically stable, and can be used as non-releasing additives. Polymers with pendant quaternary ammonium groups and hydrophobic chains exhibit antimicrobial properties due to the electrostatic interaction between polymer and cell wall, and the membrane disruptive capabilities of the hydrophobic moiety. Herein, the synthesis of cationicâ»hydrophobic polyglycidols with varying structures by post-polymerization modification is presented. The antimicrobial properties of the prepared polyglycidols against E. coli and S. aureus are examined. Polyglycidol with statistically distributed cationic and hydrophobic groups (cationicâ»hydrophobic balance of 1:1) is compared to (i) polyglycidol with a hydrophilic modification at the cationic functionality; (ii) polyglycidol with both-cationic and hydrophobic groups-at every repeating unit; and (iii) polyglycidol with a cationicâ»hydrophobic balance of 1:2. A relationship between structure and properties is presented.
RESUMO
The use of bio-based building blocks for polymer synthesis represents a milestone on the way to "green" materials. In this work, two synthetic strategies for the preparation of multifunctional polymers are presented in which the key element is the functionality of homoserine lactone. First, the synthesis of a bis cyclic coupler based on a thiolactone and homoserine lactone is displayed. This coupler was evaluated regarding its regioselectivity upon reaction with amines and used in the preparation of multifunctional polymeric building blocks by reaction with diamines. Furthermore, a linear polyglycidol was functionalized with homoserine lactone. The resulting polyethers with lactone groups in the side chain were converted to cationic polymers by reaction with 3-(dimethylamino)-1-propylamine followed by quaternization with methyl iodide.
RESUMO
Novel biodegradable materials with tunable hydrolytic degradation rate are prepared by grafting of phosphonoethylated polyglycidols with polyesters. First, the hydrolytically degradable polyester grafts are attached to polyglycidols partially grafted with phosphonoethylated diethyl esters through chemical-catalyzed grafting using tin(II) octanoate, then the diethyl ester groups are chemoselectively converted to the corresponding monoester (mixed phosphonate/phosphonic acid) using alkali metal halides. The products are characterized by means of (1)H, (13)C, and (31)P NMR spectroscopy, as well as size-exclusion chromatography and differential scanning calorimetry. The in vitro degradation of the copolymers is studied in phosphate buffered solution at 55 °C. The copolymers are of the same architecture, molecular weight, and crystallinity, only differing in the pendant phosphonate and mixed phosphonate/phosphonic acid groups, respectively. On the basis of mass loss, decrease of the molecular weight, and morphological analysis of the copolymers, the strong impact of mixed phosphonate/phosphonic acid groups on the hydrolytic degradation rate is demonstrated.