Paint & Coatings Industry - March 2008 - (Page 72)

Fluorinated Oxetane as Versatile Intermediates for Polymer F luorinated materials in many forms are used in coatings formulations. For example, fluorosurfactants are used as wetting, flow and leveling aids due to their low surface tension among other attributes. Fluoropolymers are legendary for their robustness to most forms of assault in addition to providing very low coefficients of friction and dielectric constants/refractive indices. Fluorinated intermediates that can be used to modify polymers have had less commercial penetration. The single largest use is textile repellents. Part of this is due to limited structural diversity and, more recently, international concern regarding the use and environmental fate of PFOS-, PFOA- and telomer- ((-CF) nF n ≈ 8) type materials and their possible degradation products. This concern clouds the future of fluorosurfactants, fluorochemicals and intermediates currently on the market. In the 1990s, OMNOVA Solutions developed a line of fluorochemicals based on poly(oxetane) chemistry and short (≤ C4F9) perfluoroalkyl (Rf ) groups. These fluorochemicals, marketed under the PolyFox brand name, are differentiated by the use of (a) oligomeric/ polymeric architectures and (b) short Rf groups. The combination of these two factors has several technical and environmental advantages. Typically, small molecules with short Rf groups do not have the low surface tensions and rheological properties to effectively or efficiently provide attributes such as wetting, flow and leveling when added to a coating. Attaching short R f groups to a polymer imparts significant entropic freedom to pack effectively and efficiently at a coating surface and, therefore, reduce surface tension beyond what a single short Rf group could achieve alone. Secondly, sufficient data exists to show that persistence, bioaccumulation and toxicity (PBT) concerns decrease significantly and are close to nil when Rf ≤ C4F9. Introduction The basic poly(oxetane) chemistry platform is shown in Figure 1. Synthesis involves cationic ring-opening polymerization of a fluorinated oxetane monomer using a hydroxyl-functionalized monomer and a Lewis acid catalyst. Shown in Figure 1 are mono- and difunctional intermediates. Excellent control of molecular weight and polydispersity are easy to achieve. The synthetic scheme from Figure 1 can be extended readily to other hydroxyl-containing materials including polyhydric alcohols, as shown in Figure 2. These intermediates can be used alone or in combination with other types of chemistry as basic building blocks for dendrimers or hyperbranc d branched polymers anch lymers aise o g branched polymers to raise molecular weight raise molecular weight By Richard R. Thomas | OMNOVA Solutions Inc., Akron, OH 72 MA C H 0 0 M A R CH 2008 MARCH 2 00 8 | W W W . P C I M A G . C O M AR 008 http://www.pcimag.com

Table of Contents Feed for the Digital Edition of Paint & Coatings Industry - March 2008

Viewpoint Industry News Calendar of Events Company News Mergers and Acquisitions Names in the News Marketplace Quarterly Stock Watch Reaching Strict VOC Requirements With Outstanding Durability for Industrial Maintenance and Marine Coatings A Unique Fungicide for Wood-Filled Plastic deSigns of the Times: Slacking Off! From Rocks to Nanos Shear-Free Dispersion Process Fluorinated Oxetane Oligomers as Versatile Intermediates for Polymer Modification The Effects of TPO Composition on Adhesion and Proposed Chemical Mechanism Supplier Showcase Color Management Materials Watch Products Classifieds Advertiser Index

Paint & Coatings Industry - March 2008

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