Metal- and Peroxide-Free Silicone Rubbers with Antibacterial Properties Obtained at Room Temperature

Metal- and peroxide-free silicone rubbers were obtained via a reaction between amino-containing poly(dimethylsiloxanes)(amino-terminated (APDMS-1) or a copolymer with pendant amino groups(APDMS-2)) and iodine-containing polysiloxanes (PIMSs) (Menshutkinreaction). Simple mixing of functional polymers at room temperatureresulted in forming silicone materials. The formation of ammonium cross-linkswas confirmed using solid-state H-1 and C-13 NMRspectroscopy. The equimolar ratio of NH2 groups to theI-containing moiety (1:1) was the most optimal among other ratios(2:1 and 1:2) to carry out cross-linking and led to the highest cross-linkingdensity according to the swelling measurements. PIMS/APDMS-1 (1:1)rubbers had the lowest average molecular weight of segments betweencross-links M (c) = 250 compared to PIMSs/APDMS-1(1:2) and (2:1) with M (c) = 1110 and 390,respectively. The obtained silicone rubbers showed antibacterial activityagainst Escherichia coli and Staphylococcus aureus and thereby could be appliedin biomedicine and the food industry as antibacterial coatings andmaterials.

Automated summary

Metal- and peroxide-free silicone rubbers were synthesized via a reaction between amino-containing poly(dimethylsiloxanes) and iodine-containing polysiloxanes. The equimolar ratio of NH2 groups to the I-containing moiety (1:1) showed the highest cross-linking density. The obtained silicone rubbers exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus, making them suitable for applications in biomedicine and the food industry as antibacterial coatings and materials.