The glass‐transition temperature (Tg) is a fundamental property of all organic binders, It is illustrated with polyethylene glycol (PEG)‐plasticized polyvinyl alcohol (PVA) binder systems that densification is enhanced when the binder Tg, is below the pressing temperature. This is a result of the increased deformability of the binder system and the decrease in the granule strength. Because of the reduction in the binder film strength with increasing PEG content, increasing the PEG content to lower the binder Tg, results in reductions in the compact green strength.

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Understanding of fundamental adhesion is a key issue for bonding, polymer composites, and coatings. In this study, diluted solutions of polyurethane monomers (methylene diphenyl diisocyanate isomer mixture-MDI, polypropylene ether triol-PPET) are exposed to the native surfaces of Au, Al, and Cu. The adsorption state of the molecules (from multi-to sub-monolayers) is investigated in situ by infrared external reflection absorption spectroscopy (IR-ERAS). A sequence of solvent rinsing steps helps to distinguish physisorbed from chemisorbed molecules. PPET sticks very weakly to the metals. The spectra reveal a bulk-like state. MDI adsorbs weakly on Au but the spectra differ significantly from the bulk state. On Al and Cu, MDI establishes strong adhesion. Rich new spectral features indicate a probably chemical nature of adhesion, and a specific structure in the neighboring adsorbate layer. However, detailed final conclusions on the adhesion mechanisms must not be derived without appropriate quantum mechanical modeling.

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