Morphology and mechanical properties of antimicrobial polyamide/silver composites

Silver filled antimicrobial polymers were produced from composites comprising polyamide and elementary silver powder possessing various specific surface area (SSA) by melt compounding. Different concentrations (2%, 4% and 8%) of the silver powder were incorporated in the polyamide to investigate the effect of silver loading on the mechanical properties. As the water uptake imparts antimicrobial properties, the influence of the diffused water on the mechanical properties of the composites is discussed. Scanning electron microscopy (SEM) is employed to investigate the morphology of the composites. The composite morphology found to be dependent on the SSA of the silver powder employed within the polyamide matrix. DMTA measurements were performed to follow the visco elastic behaviour of the composites. The crystallinities of the composites were evaluated using Differential Scanning Calorimetry (DSC). D 2005 Elsevier B.V. All rights reserved

Antimicrobial polymers from polypropylene/silver composites—Ag+ release measured by anode stripping voltammetry

Polypropylene/silver composites were subjected to silver ion release experiments in order to investigate their Ag+ release capabilities, a pertinent condition for antimicrobial efficacy. Polypropylene containing elementary silver powder having a specific surface area of 0.78 m2/g was considered as the principal antimicrobial filler. In addition the effectiveness of other commercial antimicrobials based on silver were also examined. Evidence is presented for the release of silver ions from these composites in an aqueous environment. The silver ion release depends on the nature of the antimicrobial filler and the polymer matrix. Scanning electron microscopy has been employed to investigate the morphology of the composite and they were found to be active against the microbes. An excellent correlation between the silver ion release experiments and the antimicrobial efficacy was found. Multifilament yarns produced from polypropylene containing elementary silver powder show excellent long term Ag+ release properties. � 2005 Elsevier B.V. All rights reserved