Structure and property development during solidification of VOC compliant automotive refinish clearcoats

Jindal, Kirti; Bhattacharya, Deepanjan; Francis, Lorraine F.; McCormick, Alon V.; Germinario, Louis T.; Williams, Chip

doi:10.1016/j.porgcoat.2009.10.030

Cited by 4 publications

(4 citation statements)

References 18 publications

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“…The solvent is having more than one effect on the rate of the polyurethane reaction, − . If we assume that the transition state is bimolecular, Figure applies.…”

Section: Resultsmentioning

confidence: 99%

“…The rate of reaction of isocyanate and polyol in mixtures of methyl ethyl ketone [MEK] and toluene [TOL] varied with composition, being slowest in toluene. Cure of PU systems have been extensively investigated for both aqueous and solvent based systems; however, the sensitivity of the cure kinetics to changes in solvent blends has not been fully addressed. − In this paper, we examine the influence of solvent with different hydrogen bonding indices [HBI] on the PU cure process.…”

Section: Introductionmentioning

confidence: 99%

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Solvent Effects in Polyurethane Cure: A Model Study

Monaghan

Pethrick

2012

Macromolecules

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The effect of change of solvent type on the rate of cure of a polyol with an isocyanate was measured using a range of different techniques. The initial stages of the cure process were followed using viscosity and Fourier transform infrared spectroscopy [FTIR] measurements. The gelation point was observed using viscosity measurements and depends on the solvent used. FTIR measurements confirm that both acceleration and inhibition of the polyurethane formation occurs with change of solvent. Comparative studies carried using mixtures of ethyl acetate/toluene and n-butyl acetate/xylene are reported. Intrinsic viscosity measurements revealed that the size of the polyol changes with temperature in a different manner depending on the solvent used. In part, the size of the polyol influences the ability for reaction to occur. Measurements of the permittivity, refractive index and solution viscosity indicates that these solvent mixtures deviate from ideality. A model to describe the observed solvent effects is proposed which includes the influence of polarity on the transition state and viscosity on the diffusion of the reactants. Using the measured viscosity and permittivity data for the mixtures, it was possible to obtain a good fit of the experimental data. This study illustrates how the polyurethane reaction is sensitive to the type of solvent used and indicates how the reactivity may be influenced by change in solvent.

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“…The solvent is having more than one effect on the rate of the polyurethane reaction, − . If we assume that the transition state is bimolecular, Figure applies.…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Solvent Effects in Polyurethane Cure: A Model Study

Monaghan

Pethrick

2012

Macromolecules

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“…The rate reaction of isocyanate and polyol in mixtures of methyl ethyl ketone and toluene varied with composition, being slowest in toluene. The cure of PU systems have been extensively investigated for both aqueous and solvent-based systems, however, the sensitivity of the cure kinetics to the solvent blend has not been fully addressed. − A detailed study of the cure processes which occurs when various esters and aromatic hydrocarbons solvents are used has been published . Comparative studies carried out in ethyl acetate/toluene and n -butyl acetate/xylene showed significant differences in the rates of the reaction with change in composition of the solvent.…”

Section: Introductionmentioning

confidence: 99%

Solvent Effects on Cure in a 2K Polyurethane—Mechanical and Dielectric Studies

Monaghan

Pethrick

2012

Ind. Eng. Chem. Res.

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The effect of change in solvent type on the processes involved in film formation of a 2K polyurethane are investigated using dynamic mechanical thermal analysis [DMTA] and dielectric relaxation [DR] measurements. The film formation and cure reactions for a polyol reacting with an isocyanate for solutions in ethyl acetate, tolene, xylene, and n-butyl acetate solutions and their mixtures are reported. Mechnical studies are used to observe the various stages of film formation and cure using a paper substrate. The fluid initially wets the substrate and film formation accompanies solvent evaporation. The rate of these initial processes correlates well with the vapor pressure of the solvent. The rate of cure of the films however is influenced by the polarity of the solvent system. Analysis of the broad band dielectric relaxation data yields conductivity data, which can be modeled to give kinetic data on the cure process. The rate of cure of this 2K system demonstrates sensitivity to the solvent composition used. The rate constant derived from conductivity data parallel those derived previously from FTIR studies. DMTA and DR measurements indicate that as cure proceeds, the glass transition temperatureT g , increases. Differences are observed in the ambient temperature-cured films, which reflect retained solvent plasticization of the matrix. Post cure aids release of trapped solvent and the final physical properties are essentially independent of the solvent used in the cure process.

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“…Several catalyst systems have been used for VOC catalytic combustion, such as those incorporating noble metals and oxides of the transition metals [1,2]. However, the VOCs from petrochemical, pesticide and foodstuff industries always contain some heteroatoms such as nitrogen, sulfur and chlorine [3,4]. One problem concerning the normal noble metal catalysts is their sensitivity to poisoning due to the presence of sulfur compounds and chlorine compounds in industrial organic exhaust gas [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Study on the poisoning tolerance and stability of perovskite catalysts for catalytic combustion of volatile organic compounds

Huang

Sun

et al. 2010

Reac Kinet Mech Cat

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La 0.8 Cu 0.2 MnO 3 and La 0.8 Sr 0.2 MnO 3 perovskite catalysts were prepared by the co-precipitation method. The resistance of these catalysts to sulfur poisoning was tested via catalytic combustion of toluene. The results show that the perovskite catalysts were poisoned in the presence of SO 2 . In the presence of dodecyl mercaptan (C 12 H 25 SH), La 0.8 Sr 0.2 MnO 3 exhibits better resistance to sulfur poisoning than La 0.8 Cu 0.2 MnO 3 . It was determined that the SO 2 deactivation is due to the formation of CuSO 4 on the catalyst surface.

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Structure and property development during solidification of VOC compliant automotive refinish clearcoats

Cited by 4 publications

References 18 publications

Solvent Effects in Polyurethane Cure: A Model Study

Solvent Effects in Polyurethane Cure: A Model Study

Solvent Effects on Cure in a 2K Polyurethane—Mechanical and Dielectric Studies

Study on the poisoning tolerance and stability of perovskite catalysts for catalytic combustion of volatile organic compounds

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