Specialty Coatings @ MMI
Coatings are thin layers of materials purposely deposited on surfaces in order to affect their appearance, durability or interaction with the surrounding environment(s). They represent a very large segment of overall chemical industry and one of the most important fields of application for both synthetic and natural polymers. In fact, polymers are ideal substances for coating applications because of their chemical and rheological (i.e., flow) properties.
Polymer coatings are generally prepared by spreading a more or less viscous liquid composition over the surface to be coated and allowing the composition to form the coating, most often by chemical crosslinking of individual polymer chains. The composition generally comprises of a film-forming substance, or combination of substances (such as polymers or prepolymers), called binder, an additive or combination of additives, such as pigments, dyes, fillers, stabilizers, catalysts, or various other chemical agents, and a volatile liquid (solvent or diluents) which makes spreading easier and which evaporates as the coating forms.
The term coatings encompasses a variety of different types of coatings, including conventional paints, varnishes, enamels, lacquers, water-emulsion and solution finishes, non-aqueous dispersions or organosols, plastisols, and powder coatings which do not contain volatile liquids. Polymer coatings are applied to a variety of different surfaces including metals, glass, ceramics, other polymers, wood, masonry, paper, textiles, etc., and their main purpose is most often to provide protection or for decorative reasons. Protection may be required from corrosion, weathering, aging or mechanical damage and such coatings are usually referred to as commodity coatings. They are generally available in many grades and forms to meet a variety of applications and specific requirements of desired processing techniques, and their properties can be adjusted by varying types and relative amounts of additives. Often, these grades are specially designed and formulated, even tailor-made, to meet particular application and/or service requirements and, in a sense, they might be regarded as ”specialties".
In addition to these, there are also numerous other areas of non-traditional applications where polymer coatings need to provide more than just protection and decoration, and often both protection and some other functionally essential feature or combination of features that were previously not considered suitable or feasible. Such applications require specialty coatings that effectively functionalize coated surfaces and enable them to exhibit desired use properties that they otherwise do not posses. Such properties may include sophisticated optical properties (reflection or other unusual appearances), ability to photonically interact with irradiation in a special way, ability to exhibit unusual electrical or thermal behavior, printing or lithographic sensitivity or resistivity, super hydrophobicity or hydrophilicity, antifouling and/or antimicrobial characteristics, sensory abilities, decontamination, etc.
In general, materials for such coatings are produced in smaller quantities than their commodity counterparts because they are also needed in smaller quantities than the latter, but are usually much more costly and often represent true “modern marvels” from the cutting edge of science of molecular engineering of materials. It is precisely this type of coatings that we are particularly interested in at MMI. They are often based on our unique dendritic polymer technologies, which include both dendrimers and hyperbranched polymers, and they open new vistas for coating technologies that have not been available before.
Some of these unique properties include encapsulation potential (via host-guest interactions between additives and intramolecular cargo spaces of dendritic polymers),unprecedented honeycomb-like coating structures which provide great potential for nanolithography and nano-patterning, smart decontaminating coatings which can combine sensory and decontamination functions, environmentally benign antifouling and antimicrobial coatings, highly hydrophobic coatings for anti-icing protection or for high performance lithographic rolls, coatings with unprecedented photonics and/or electronic properties, etc. In addition, these properties can be combined with an added possibility of controlling mechanical properties and coatings’ robustness by adjusting the degree of crosslinking that their dendritic polymer precursors generously offer.