Organic binders polyurethane based

Organic polymers and resins have also been used for zeolite binding. An early example is the use polyurethane in the formahon of vibration-resistant zeolite porous bodies for refrigerant drying [90]. Organic binders such as cellulose acetate and other cellulose-based polymers have also used to mitigate problems with binder dissolution in aqueous phase separations [91, 92]. Latex has also been used as a water-stable organic binder [93]. More recently, thermoplastic resins, such as polyethylene have also been used as binders for zeolites [94]. 

Paints are complex formulations of polymeric binders with additives including anti-corrosion pigments, colors, plasticizers, ultraviolet absorbers, flame-retardant chemicals, etc. Almost all binders are organic materials such as resins based on epoxy, polyurethanes, alkyds, esters, chlorinated rubber and acrylics. The common inorganic binder is the silicate used in inorganic zinc silicate primer for steel. Specific formulations are available for application to aluminum and for galvanized steel substrates. 

Since the 1970s a trend to use water-based coating systems and glues instead of solvent-based products has been apparent. Most water-based paints and lacquers use polyurethane or acrylate as binders. For technical reasons the systems still contain organic cosolvents as well as pigments, biocides and surfactants (Hansen et al., 1987). 

Organic coatings are used to block the penetration of carbon dioxide or chloride ions. They form a continuous polymeric film on the surface of the concrete, of a thickness ranging from 100 to 300 pm. The binder can already be present in the liquid paint as a polymer, or the polymer can be formed due to chemical reactions between monomeric components that are mixed just before application. Modem coating systems are usually built up of several layers applied consecutively. They are compatible with the alkalinity of the concrete and are based on various types of polymers (e. g. acrylate, polyurethane, epoxy), pigments and additives, and are made suitable for application by the addition of solvents or diluents. 

The superprimer formulation is usually based on an ionic or non-ionic aqueous resin dispersion. The solid content of the water-borne resin is often around 55wt% and it may contain small amounts of organic solvents. Typical resins used in the primers are epoxies, acrylates and polyurethanes. The minor binder is incorporated in order to improve a particular coating property such as cold formability. Table 1 gives an overview of the family of superprimers based on different resin-cross-linker-silane-pigment combinations invented and investigated in our laboratory [7-11]. 

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