Atomic force microscopy polyurethane

Atomic force microscopy and attenuated total reflection infrared spectroscopy were used to study the changes occurring in the micromorphology of a single strut of flexible polyurethane foam. A mathematical model of the deformation and orientation in the rubbery phase, but which takes account of the harder domains, is presented which may be successfully used to predict the shapes of the stress-strain curves for solid polyurethane elastomers with different hard phase contents. It may also be used for low density polyethylene at different temperatures. Yield and rubber crosslink density are given as explanations of departure from ideal elastic behaviour. 17 refs. 

Atomic force microscopy has been used to evaluate the nature and size of the polyurethane structure at the surface of a sample. In this method, the surface of the sample is coated with a layer of gold and a probe scans over the surface. As the nature of the chemistry below the probe changes, the force field acting on the probe changes. The hard segment clusters can be visualized. 

M.B. Fritzen-Garcia, B.G. Zanetti-Ramos, C.S. De Oliveira, V. Soldi, A. Pasa, and T.B. Creczynski-Pasa, Atomic force microscopy imaging of polyurethane nanoparticles onto different solid substrates. Mat. Sci. Eng. C., 29(2), 405-409 (2009). 

AFM, atomic force microscopy DMA, dynamic mechanical analysis DSC, differential scanning calorimetry flVR, oxidized natural rubber FTIR, Fourier transform infrared spectroscopy NR, natural rubber PLA, poly(lactic acid) QP, quaternary phosphonium salt TGA, thermogravimetric anal is TPU, thermoplastic polyurethane XPCL, end-carboxylated teledielic... 

It has been well established by Cooper and Tobolsky that the unique properties of polyurethanes are strongly linked to its two-phase morphology [21], Characterization of microphase separation is performed using a variety of techniques including dynamic mechanical thermal analysis (DMTA), Fourier transform infrared spectroscopy (FTIR), small-angle X-ray scattering (SAXS), and atomic force microscopy. Consideration of both the thermodynamic driving forces and the kinetics is needed to elucidate microstructure formation in polyurethanes [60-66],... 

Surface science. Surface characterization studies included those for base polyurethane segmented block copolymers and base polymer modified by <2 wt% U-P[AB], Surface analytical techniques included tapping mode atomic force microscopy (TM-AFM), X-ray photoelectron spectroscopy (XPS), wetting behavior by dynamic contact angle (DCA) analysis and sessile drop measurements, and attenuated total reflectance infrared spectroscopy (ATR-IR). Contact antimicrobial behavior of U-P[AB] containing hydantoin and aikylammonium B side chains was determined by spray-on and sandwich tests previously described in detail elsewhere [11, 22, 38]. 

Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM) followed by dynamic mechanical parameter tests were used for the investigation of the morphology of unsaturated polyester/diol-polyurethane hybrid polymer networks (UP/PU HPNs). The effect of phase separation on mechanical properties was described [142]. 

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