Interfacial Rheological Properties of a Series of Bolaamphiphilic Poly(fluorooxetane)s

Abstract

Interfacial rheological studies were performed on a series of bolaamphiphilic R,ω-(diammonium disulfato)-poly(fluorooxetane)s of several perfluoroalkyl chain lengths. Similar measurements were performed on a small-molecule, anionic fluorosurfactant with a -C8F17 perfluoroalkyl group that is known to be an effective flow and leveling aid in aqueous coatings. Dilational viscoelasticities were measured for the fluorosurfactants as a function of concentration and oscillation rate. Elasticities were found to increase with increasing perfluoroalkyl chain length. All elasticities exhibited a strain rate dependence indicative of the influence of diffusional relaxation on elasticity values. Phase angles were found to be in the range for diffusional relaxation and decreased with increasing concentration and strain rate. Using interfacial rheological data, characteristic fluid dynamics numbers were calculated for the fluorosurfactants. Among these was the Marangoni number. Calculated Marangoni numbers for the poly(fluorooxetane)s were of the same order of magnitude as that for the small-molecule, long perfluoroalkyl chain surfactant. The poly(fluorooxetane)s all have equilibrium surface tensions greater than that of the small-molecule, long perfluoroalkyl chain surfactant, yet show similar abilities to aid in flow and leveling in aqueous coatings at comparable concentrations. Rheological measurements demonstrate that equilibrium surface tension alone is not enough to explain the fluid dynamics processes occurring during flow and leveling.

Perfluoroalkyl and polyfluoroalkyl substances in the environment: Terminology, classification, and origins

“…These fluorinated oxetane polymers (Table 4) are offered in many forms and functionalities primarily as fluorosurfactants and coatings additives (Kausch et al 2002; Kausch et al 2003a, 2003b; Thomas 2006; Omnova Solutions 2011). …”

“…An alternative fluorinated polymer technology to those described thus far originates from the reaction of polyfluorinated alcohols with oxetanes bearing a -CH 2 Br group in their side chains, to create oxetane monomers that can undergo ring-opening polymerization to give side-chain–polyfluorinated polyethers ( Figure 9 ). These fluorinated oxetane polymers ( Table 4 ) are offered in many forms and functionalities primarily as fluorosurfactants and coatings additives (Kausch et al 2002 ; Kausch et al 2003a , 2003b ; Thomas 2006 ; Omnova Solutions 2011 ).…”

Effect of waterborne epoxy resin sizing on the surface and properties of high‐strength‐high‐modulus polyimide fibers

“…Measuring the dynamic contact angles between the two liquids (the deionized water and ethylene glycol) and PI fibers, according to the OWRK theory, 29–31 the surface free energy is exhibited in Table 6 and Figure 9. The unsized PI fibers possess contact angles of 104.13° in water and 94.09° in glycol, while the surface energy is 10.46 mJ/m 2 .…”

Synthesis, Characterization, and Interfacial Properties of an Oligomeric, Cationic Fluorooxetane

“…The synthetic scheme used to prepare the cationic oligo(fluorooxetane) surfactant is shown in Figure . Details of the synthesis and characterization of anionic and diol versions of the fluorinated oxetane oligomer and polymers have been given previously. − The synthetic route employed in the earlier work was not used to synthesize the cationic oligomer because there is no simple way to bond a precursor alkylhalide to the oligo(oxetane) backbone. Instead, a haloalcohol initiator scheme was employed wherein 3-iodo-1-propanol was prepared by a halogen metathesis reaction using 3-chloro-1-propanol and sodium iodide.…”

“…The viscoelastic properties attributed to an interface play a crucial role in determining the stability of foams and emulsions as well as in the uniformity of film coatings. Despite the widespread applications of fluorosurfactants, there have been few published studies on the interfacial rheological properties of these materials at the air−water interface. , In that regard, dilational viscoelastic properties of the cationic oligo(fluorooxetane) surfactant in neutral water at room temperature spanning adsorption isotherm concentrations and as a function of the strain rate have been measured using an oscillating bubble rheometer. This technique has been outlined elsewhere 21,24-26 and will be covered here only briefly.…”