Characterization of the surface content, hydrolysis ratio, and condensation degree of polyalkoxysiloxane segregated to the surface of a polyurethane crosslinked film by X‐ray photoelectron spectroscopy

Abstract

We report, using an electron spectrometer equipped with both monochromatized Al Kα and unmonochromatized Mg Kα sources, the quantitative characterization of the surface content, hydrolysis ratio, and condensation degree of polyalkoxysiloxane segregated to the surface of a polyurethane crosslinked film consisting of acryl polyol, polyisocyanate, and polyalkoxysiloxane. Unmonochromatized Mg Kα X‐ray irradiation extremely accelerated the decomposition of alkoxy groups of polyalkoxysiloxane. The surface content and hydrolysis ratio were determined from C 1s, Si 2p, and N 1s spectral intensities measured with monochromatized Al Kα X rays after decomposition by unmonochromatized Mg Kα X‐ray irradiation. The condensation degree was determined by the kinetic energy of the silicon KLL Auger electron after decomposition. We applied the established characterization method for a polyurethane film containing polyalkoxysiloxane. After 20 days, the surface content of polyalkoxysiloxane was greater than 60 wt %, the hydrolysis ratio ranged from 0.8 to 0.95, and the higher hydrolysis ratio resulted in a larger condensation degree. The hydrophilicity of the film surface became higher as the surface content and hydrolysis ratio increased, and the crack density became higher as the condensation degree increased. A method for characterizing the practical properties of coating film surfaces containing polyalkoxysiloxane was established. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2917–2926, 2002

Synthesis and thermal crosslinking of benzophenone‐modified poly(dimethylsiloxane)s

“…The surface migration of the siloxane segment has also been observed in polyurethane films produced in the presence of a polyalkoxysiloxane 27. The hydrolysis of SiOC bond linkages is followed by silanol condensation, and this produces a low‐surface‐energy siloxane 27…”

“…X‐ray photoelectron spectroscopy of materials with long siloxane segments indicates that the lower surface energy siloxane migrates to the surface of the polymer films 26. The surface migration of the siloxane segment has also been observed in polyurethane films produced in the presence of a polyalkoxysiloxane 27. The hydrolysis of SiOC bond linkages is followed by silanol condensation, and this produces a low‐surface‐energy siloxane 27…”

Synthesis and thermal crosslinking of benzophenone‐modified poly(dimethylsiloxane)s

“…The surface migration of the siloxane segment has also been observed in polyurethane films produced in the presence of a polyalkoxysiloxane 27. The hydrolysis of SiOC bond linkages is followed by silanol condensation, and this produces a low‐surface‐energy siloxane 27…”

“…X‐ray photoelectron spectroscopy of materials with long siloxane segments indicates that the lower surface energy siloxane migrates to the surface of the polymer films 26. The surface migration of the siloxane segment has also been observed in polyurethane films produced in the presence of a polyalkoxysiloxane 27. The hydrolysis of SiOC bond linkages is followed by silanol condensation, and this produces a low‐surface‐energy siloxane 27…”

Distribution of melamine in polyester–melamine surface coatings cured under nonisothermal conditions

“…Changes in the structure with curing, particularly the surface structure, have also been demonstrated in other systems. Tomita et al 11 reported the use of XPS to study the surface segregation of poly(alkoxysiloxane) additives to polyurethanes during curing. Using Al K␣ X-rays, they were able to quantify the amount of poly-(alkoxysiloxane) at the surface, the hydrolysis ratio, and the degree of condensation.…”

Effect of degree of saponification on the rheological properties of syndiotactic poly(vinyl alcohol)/ water solution

“…Changes in the structure with curing, particularly the surface structure, have also been demonstrated in other systems. Tomita et al11 reported the use of XPS to study the surface segregation of poly(alkoxysiloxane) additives to polyurethanes during curing. Using Al Kα X‐rays, they were able to quantify the amount of poly(alkoxysiloxane) at the surface, the hydrolysis ratio, and the degree of condensation.…”

Synthesis and thermal crosslinking of benzophenone‐modified poly(dimethylsiloxane)s

“…The surface migration of the siloxane segment has also been observed in polyurethane films produced in the presence of a polyalkoxysiloxane 27. The hydrolysis of SiOC bond linkages is followed by silanol condensation, and this produces a low‐surface‐energy siloxane 27…”

“…X‐ray photoelectron spectroscopy of materials with long siloxane segments indicates that the lower surface energy siloxane migrates to the surface of the polymer films 26. The surface migration of the siloxane segment has also been observed in polyurethane films produced in the presence of a polyalkoxysiloxane 27. The hydrolysis of SiOC bond linkages is followed by silanol condensation, and this produces a low‐surface‐energy siloxane 27…”

Distribution of melamine in polyester–melamine surface coatings cured under nonisothermal conditions

“…Changes in the structure with curing, particularly the surface structure, have also been demonstrated in other systems. Tomita et al 11 reported the use of XPS to study the surface segregation of poly(alkoxysiloxane) additives to polyurethanes during curing. Using Al K␣ X-rays, they were able to quantify the amount of poly-(alkoxysiloxane) at the surface, the hydrolysis ratio, and the degree of condensation.…”

Effect of degree of saponification on the rheological properties of syndiotactic poly(vinyl alcohol)/ water solution

“…Changes in the structure with curing, particularly the surface structure, have also been demonstrated in other systems. Tomita et al11 reported the use of XPS to study the surface segregation of poly(alkoxysiloxane) additives to polyurethanes during curing. Using Al Kα X‐rays, they were able to quantify the amount of poly(alkoxysiloxane) at the surface, the hydrolysis ratio, and the degree of condensation.…”

Synthesis and thermal crosslinking of benzophenone‐modified poly(dimethylsiloxane)s

“…The surface migration of the siloxane segment has also been observed in polyurethane films produced in the presence of a polyalkoxysiloxane 27. The hydrolysis of SiOC bond linkages is followed by silanol condensation, and this produces a low‐surface‐energy siloxane 27…”

“…X‐ray photoelectron spectroscopy of materials with long siloxane segments indicates that the lower surface energy siloxane migrates to the surface of the polymer films 26. The surface migration of the siloxane segment has also been observed in polyurethane films produced in the presence of a polyalkoxysiloxane 27. The hydrolysis of SiOC bond linkages is followed by silanol condensation, and this produces a low‐surface‐energy siloxane 27…”

Distribution of melamine in polyester–melamine surface coatings cured under nonisothermal conditions

“…Changes in the structure with curing, particularly the surface structure, have also been demonstrated in other systems. Tomita et al 11 reported the use of XPS to study the surface segregation of poly(alkoxysiloxane) additives to polyurethanes during curing. Using Al K␣ X-rays, they were able to quantify the amount of poly-(alkoxysiloxane) at the surface, the hydrolysis ratio, and the degree of condensation.…”

Effect of degree of saponification on the rheological properties of syndiotactic poly(vinyl alcohol)/ water solution

“…Changes in the structure with curing, particularly the surface structure, have also been demonstrated in other systems. Tomita et al11 reported the use of XPS to study the surface segregation of poly(alkoxysiloxane) additives to polyurethanes during curing. Using Al Kα X‐rays, they were able to quantify the amount of poly(alkoxysiloxane) at the surface, the hydrolysis ratio, and the degree of condensation.…”