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

Tomita, Rie; Urano, Satoshi; Kohiki, Shigemi

doi:10.1002/pola.10331

Cited by 7 publications

(4 citation statements)

References 38 publications

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“…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…”

Section: Introductionmentioning

confidence: 92%

“…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…”

Section: Introductionmentioning

confidence: 98%

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

Mabry

Weber

2004

J. Polym. Sci. A Polym. Chem.

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Dihydridocarbonyltris(triphenylphosphine)ruthenium catalyzes the regiospecific anti-Markovnikov addition of an ortho COH bond of benzophenone across the COC double bonds of ␣,-bis(trimethylsilyloxy)copoly(dimethylsiloxane/vinylmethylsiloxane) (99:1), ␣,-bis(vinyldimethylsilyloxy)poly(dimethylsiloxane), and 1,3-divinyltetramethyldisiloxane to yield ␣,-bis(trimethylsilyloxy)copoly[dimethylsiloxane/ 2-(2Ј-benzophenonyl)ethylmethylsiloxane]), ␣,-bis[2-(2Ј-benzophenonyl)ethyldimethylsilyloxy]poly(dimethylsiloxane), and 1,3-bis[2-(2Ј-benzophenonyl)ethyl]tetramethyldisiloxane, respectively. These materials have been characterized with 1 H, 13 C, and 29 Si NMR and IR spectroscopy. Their molecular weight distributions have been determined by gel permeation chromatography. The thermal stability of the polymers has been measured by thermogravimetric analysis, and their glass-transition temperatures (T g 's) have been determined by differential scanning calorimetry. The molecular weight distribution, thermal stability, and T g 's of the modified polysiloxanes are similar to those of the precursor polymers. The molecular weights of these materials can be significantly increased via heating to 300°C for 1 h. This may be due to crosslinking, by pyrocondensation, of pendant anthracene groups, which are produced by the pyrolysis of the attached ortho-alkyl benzophenones. UV spectroscopy of the pyrolysate of 1,3bis[2-(2Ј-benzophenonyl)ethyl]tetramethyldisiloxane has confirmed the presence of pendant anthracene groups. Thermal crosslinking by the pyrocondensation of pendant anthracene groups has been verified by the pyrolysis of ␣,-bis(trimethylsilyloxy)copoly[dimethylsiloxane/2-(9Ј-anthracenyl)ethylmethylsiloxane] (97:3).

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Section: Introductionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 98%

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

Mabry

Weber

2004

J. Polym. Sci. A Polym. Chem.

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“…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.…”

Section: Introductionmentioning

confidence: 99%

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

Gamage

Hill

Lukey

et al. 2003

J. Polym. Sci. A Polym. Chem.

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The influence of experimental cure parameters on the diffusion of reactive species in polyester–melamine thermoset coatings during curing has been investigated with X‐ray photoelectron spectroscopy and attenuated total reflectance Fourier transform infrared. The diffusion of melamine plays a vital role in the curing process and, therefore, in the ultimate properties of coatings. At a low (<20%) hexamethoxymethylmelamine (HMMM) crosslinker concentration, the matrix composition is uniform, but at high HMMM concentrations, excess HMMM rapidly segregates to the air–coating interface. The rate of migration is governed by the difference in the surface free energies of polyester and HMMM and the concentration gradient of HMMM between the bulk and the surface. An increased rate of energy absorption also increases the rate of migration of HMMM to the surface. A physical model has been proposed to explain this surface segregation phenomenon in terms of cocondensation and self‐condensation reactions. It suggests that an appropriate amount of melamine can be segregated on the surface and allowed to self‐condense to form a desired thickness of a melamine topcoat through the control of the binder composition and cure conditions. This technique can be implemented to apply a melamine topcoat during cure. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 83–91, 2004

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“…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.…”

Section: Introductionmentioning

confidence: 99%

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

Lyoo¹,

Seo²,

Yeum³

et al. 2002

J of Applied Polymer Sci

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ABSTRACT:To identify the effect of degree of saponification (DS) of syndiotactic poly(vinyl alcohol)s (s-PVA)s having similar tacticity and molecular weight on the rheological properties of s-PVA/water solution, four kinds of (s-PVA)s with assigned (DS)s, from 93.1 to 97.5%, were prepared by copolymerization of vinyl pivalate (VPi) and vinyl acetate (VAc), followed by saponifying the corresponding copoly(VPi/VAc). The DS played a significant role in rheological behavior. Over the frequency range of 10 Ϫ1 to 10 2 rad/s s-PVA with higher DS shows more shear thinning at similar molecular weight and tacticity of polymer, suggesting that PVA molecules are more readily oriented as DS increases. This may provide indirect evidence of the spontaneous in situ orientation of s-PVA molecules at the late stage of saponification. Yield stress is higher for s-PVA with higher DS at similar molecular weight and tacticity of s-PVA. This indicates that more domains with internal order are produced at higher saponification. These facts result from increase in stiffness of s-PVA molecules with proceeding the saponification reaction.

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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

Cited by 7 publications

References 38 publications

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

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

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

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

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