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

Study of the Mechanical Properties of Nano Silver Nitrate Filled Polypropylene Composites

In this investigation, the mechanical properties of silver nitrate nanoparticles filled polypropylene composite is evaluated. The silver nitrate particles are added to the matrix by 1, 3, 5, and 10% by weight. The composite is prepared by adding the filler to polypropylene under heat and mix the mixture by mechanical stirrer. Then after the test samples are prepared under hot press. The tensile tests are carried out. The tensile strength, yield stress, tensile modulus, and the percentage of elongation to break are obtained and evaluated. The results show that the elastic modulus of the composite is in increase while tensile strength, rupture strength, and the percentage of elongation to break is in decrease with the increase in the content of silver nitrate particle fillers. The morphology, structure, and size of the silver nitrate particles are evaluated by scanning electron microscope

Preparation and characterization of antibacterial zeolite-polyurethane composites

In this study, antibacterial properties were induced in polyurethane (PU) films by the incorporation of Ag+-loaded zeolites as fillers. The mechanical and thermal properties of the prepared composites were also investigated. For this purpose, two different types of zeolite microparticles, high-silica zeolite beta crystals and low-silica zeolite A crystals, were synthesized. Ag+ was added by ion exchange, and these particles were incorporated into the PU prepolymer, which was prepared from its main components of toluene diisocyanate and polypropylene ethylene glycol (medical purity). Microbiological tests revealed that both types of composites, prepared by the addition of Ag+-containing zeolite beta or zeolite A to the PU matrix, had antibacterial properties. It was demonstrated for the first time that a high-silica zeolite (zeolite beta) and its composite film could be effectively employed as antibacterial materials. Furthermore, mechanical and thermal characterization of the composites showed that the zeolites enhanced the mechanical properties of the polymer and did not cause any deterioration in its thermal properties. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110: 2854-2861, 200