No abstract

Polyamidoamine (PAMAM) dendrimer of zero generation was synthesized and characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopic techniques. A novel chemistry has been developed to synthesize polyurea microcapsules containing solvent and linseed oil as the active healing agent by interfacial polymerization of commercial methylene diphenyl diisocyanate (MDI) and dendritic 0.0 G PAMAM capable of cross-linking to form a shell material. Spherical with some irregular shape microcapsules were observed with average diameter from 20 to 270 μm at different agitation rates (3000–8000 rpm). Interfacial interaction between polyurea microcapsules and polyurethane (PU) coating were studied by FTIR, and this showed that chemical bonds were formed by the reaction between isocyanates and the amine groups present on the wall of microcapsules. The thermal stability of the microcapsules showed that prepared microcapsules experienced excellent stability up to 380 °C. The anticorrosive performance of PU coatingd loaded with different percentages of microcapsules was carried out in 5% NaCl aqueous solution. The results showed that the composite provides satisfactory anticorrosive properties at 5% capsule loading under an accelerated corrosion process. The idea and approach presented in this work have the potential to fabricate microcapsules which could provide better anticorrosive and mechanical properties to coating composites.

No abstract

No abstract

Phenol-formaldehyde microcapsules with linseed oil as an active agent were produced by applying in situ polymerization method. The anticorrosion and selfhealing efficiency of the synthesized materials were studied. Characteristics of these synthesized capsules were studied by Fourier transform infrared spectroscopy, and surface morphology was analyzed by using scanning electron microscope. Controllable particle size was estimated at different rpm of stirrer and particle size was checked under microscope and also by using particle size analyzer. The anticorrosion performance of encapsulated microcapsules coated with epoxy resin was carried out in 5% NaCl aqueous solution. The effectiveness of linseed oil filled microcapsules was investigated for healing the cracks generated in paint films or coatings. It was found that the cracks were successfully healed when linseed oil was released from ruptured microcapsules. Further, linseed oilhealed area was found to prevent effectively the corrosion of the substrate in immersion studies.

No abstract

A simple technique is described for constructing a glucose sensor by the entrapment of glucose oxidase (GOD) in a polyaniline (PA), poly(o‐toluidine) (POT) and their copolymer poly(aniline‐co‐o‐toluidine) (PA‐co‐POT) thin films, which were electrochemically deposited on a platinum plate in phosphate and acetate buffer. The maximum current response was observed for PA, POT, and PA‐co‐POT GOD electrodes at pH 5.5 and potential 0.60 V (v. Ag/AgCl). The phosphate buffer gives fast response as compared to acetate buffer in amperometric measurements. PA GOD electrode shows the fastest response followed by PA‐co‐POT and POT GOD electrodes. Copyright © 2004 John Wiley & Sons, Ltd.

No abstract