Fluorinated segmented polyurethane anionomers for water–oil repellent surface treatments of cellulosic substrates

Abstract

Three model structures of linear segmented anionomeric polyurethanes based on perfluoropolyether dimethylol-terminated oligomers, isophorone diisocyanate, and dimethylol propionic acid were synthesized and obtained in the form of aqueous dispersions. The structures differed from each other in the chemical nature of the chain extender (diol or diamine) and in the content of carboxylic acid. Dispersions and polymer films were characterized by dynamic light scattering, dynamic mechanical analysis, differential scanning calorimetry, and contact angle measurements. Diluted aqueous dispersions were also evaluated as protective sizing agents in paper treatment, both as bulk modifiers and as surface treatments. Paper sheets characterized by high water and oil repellence were obtained. The results showed that performance is mainly related to the ionic group content of the polymer and to its molecular architecture.

Novel conductive nanocomposites from perfluoropolyether waterborne polyurethanes and carbon nanotubes

“…Table presents the values of glass transition ( T g ) temperature at increasing COOH‐CNT concentration. Because of the presence of urethane moieties, the corresponding nanocomposites showed two distinct glass transitions that can be ascribed to the nanoscale segregation of the PFPE phase and the urethane phase resulting from their different solubility parameters . In particular, the lower T g value is related to the soft fluorinated phase ( T g F ), while the higher T g value is associated to the hydrogenated urethane phase ( T g H ).…”

“…The preparation of the waterborne PFPE‐PUs used in this study is based on a process described elsewhere (see Figure S1 in the Supporting Information for the molecular structure) . Such system is an aqueous dispersion of an anionic segmented PU containing PFPE blocks and carboxylate functional side groups with a solid content of 26% w/w and a molecular weight of about 20,000 g/mol.…”

“…Among them, perfluoropolyether (PFPE) functional oligomers have been used as building blocks for the realization of high performance copolymers, mainly based on the polyurethane chemistry . Thanks to these characteristics, these systems have been exploited in a variety of scientific and technological fields that include original equipment manufacturing coatings, plastic coatings, rubber seals, and water/oil repellent finishings . PFPE‐based polyurethanes (PFPE‐PUs) are normally employed as highly insulating materials.…”

Study of metal protective hydrophobic coatings from waterborne polyurethane ionomers

“…In these products it was observed that water permeability, barrier properties and durability are largely affected by phase segregation phenomena involving the apolar fluoroether segments and polar urethane moieties [2]. More recently waterborne versions of fluoroether containing polyurethanes have been described [5,6]; they are based on the introduction within the polymer chain of ionic groups which act as internal emulsifiers allowing the formation of stable and environmentally friendly aqueous dispersions.…”

Preparation and Characterization of Fluorinated Hydrophobic UV-Crosslinkable Thiol-Ene Polyurethane Coatings

“…However, the low reaction activity of the fluorinated polyol leads to the low molecular weight and poor mechanical property of the resulting products, which may restrict the wide applications of fluorinated polyurethane (FPU). Moreover, compared to other polyols, the fewer species and quantities of the fluorinated polyol further limited their use as modifying monomers for fluorinated polyurethane [14][15][16][17].…”