High-solids coatings based on polyurethane chemistry

Desai

International Journal of Polymeric Materials

2005

SUMMARY:Polymers containing urethane units were synthesized by solution polymerization of bisphenols A, C, and F with diisocyanates viz. toluene-2,4-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate, respectively. Thus obtained polymers were pale yellow amorphous powders. These polymers were characterized by infrared spectral studies and nitrogen content. The number-average molecular weights (Q) were estimated from conductometric titration and limiting viscosity number [q] in dimethyl formamide. From thermogravimetric analyses, the thermal behaviour was studied. Kinetic parameters for their degradation were computed. ZUSAMMENFASSUNG:Polymere mit Urethaneinheiten wurden durch L6sungspolymerisation der Bisphenole A, C und F mit Diisocyanaten wie Toluol-2,4-diisocyanat, Hexamethylendiisocyanat, Isophorondiisocyanat bzw. Diphenylmethandiisocyanat hergestellt. Die erhaltenen Polymeren waren blaagelbe Pulver. Diese Polymeren wurden durch IRSpektroskopie und Bestimmung des Stickstoffgehalts charakterisiert. Die zahlenmittleren Molekulargewichte (4) wurden durch Leitftlhigkeitstitration und Bestimmung der Grenzviskositiltszahl in Dimethylformamid ermittelt. Mittels Thermogravimetrie wurde das thennische Verhalten untersucht. Die kinetischen Parameter des Abbaus wurden berechnet .

Section: Resultsmentioning

confidence: 99%

“…They are produced by the reaction between diols and diisocyanates. In terms of application, they find a number of applications like fibers and film [1], paints lacquers [2], adhesives [3,4], foam [5,6], and elastomer [7,8]. By compounding with additives the polyurethanes are processed into the referenced articles.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Novel Colored Polyurethanes

Desai

International Journal of Polymeric Materials

2005

“…This phenomenon is due to the increase of crosslinking density. 21 If the viscosity of the modified polyester is too low, workability is lowered; for example, when painting with a brush the film surface is not smooth and leveling22 is difficult. On the contrary, if the viscosity is too high, some disadvantages are apparent: the solid component must be lowered and, because of the decrease in solubility, a polar solvent such as cellosolve acetate is necessary instead of toluene.…”

Section: Changes Of Kinematic Viscosity Of 23-dibromo Modified Polyementioning

confidence: 99%

Preparation and characteristics of two-component polyurethane flame retardant coatings using 2,3-dibromo modified polyesters

Park¹,

Hahm²,

Park³

1996

J. Appl. Polym. Sci.

SYNOPSISTwo-component polyurethane flame retardant coatings were prepared by blending 2,3dibromo modified polyesters (2,3-DBPOs) and polyisocyanate. 2,3-DBPOs were synthesized by polycondensation of 2,3-dibromopropanoic acid, a flame retardant aliphatic carboxylic acid, with 1,4-butanediol, trimethylolpropane, and adipic acid. The content of 2,3-dibromopropanoic acid was varied a t 10, 20, and 30 wt % for the polycondensation reaction. Various physical properties of these new flame retardant coatings were comparable to nonflame-retardant coatings. They showed desirable properties for a flame retardant coating such as rapid drying and 9-12 h of pot life. Coatings with 30 wt % 2,3-dibromopropanoic acid did not burn using the vertical burning test. 0 1996 John Wiley & Sons, Inc.

“…[1,2] Thep olyurethane market continues rapid growth, owing to the superior properties of these polymers in numerous applications, [3][4][5] including as sealants, [6,7] adhesives, [8,9] foams, [10,11] and coatings. [1,2] Thep olyurethane market continues rapid growth, owing to the superior properties of these polymers in numerous applications, [3][4][5] including as sealants, [6,7] adhesives, [8,9] foams, [10,11] and coatings.…”

mentioning

confidence: 99%

“…Distinct from conventional deblocking chemistry involving organometallic compounds and high temperatures,the method we describe is metal-free and operates at or slightly aboveroom temperature.T he use of fluorescent blocking agents enabled visual and spectroscopic monitoring of blocking/deblocking reactions,a nd the selected conditions proved applicable to urethanes containing avariety of blocking groups.The method additionally enabled aone pot deblocking and polymerization with a,w-diols.O verall, this deblocking/polymerization strategy offers aconvenient and efficient solution to problems that have limited the breadth of applications of polyurethane chemistry.Since their discovery by Bayer and co-workers,p olyurethane-based materials have elevated to ap osition of major societal importance. [1,2] Thep olyurethane market continues rapid growth, owing to the superior properties of these polymers in numerous applications, [3][4][5] including as sealants, [6,7] adhesives, [8,9] foams, [10,11] and coatings. [12,13] Polyurethane properties are tailored by monomer selection, [14][15][16] involving diisocyanates,d iols,a nd/or polyols.…”

mentioning

confidence: 99%

Fluoride‐Catalyzed Deblocking: A Route to Polymeric Urethanes

et al. 2018

We report af luoride-catalyzed deblocking of urethanes as "blocked" isocyanates.O rganic and inorganic sources of fluoride ion proved effective for deblocking urethanes and for converting polyurethanes to small molecules. Distinct from conventional deblocking chemistry involving organometallic compounds and high temperatures,the method we describe is metal-free and operates at or slightly aboveroom temperature.T he use of fluorescent blocking agents enabled visual and spectroscopic monitoring of blocking/deblocking reactions,a nd the selected conditions proved applicable to urethanes containing avariety of blocking groups.The method additionally enabled aone pot deblocking and polymerization with a,w-diols.O verall, this deblocking/polymerization strategy offers aconvenient and efficient solution to problems that have limited the breadth of applications of polyurethane chemistry.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under https://doi.