Urethane isophorone

Urethane (isophorone-caprolactone) diacrylates Acrylated soybean or linseed oils... 

Type II Urea-Urethane Oligomers. To 11.6g (0.1 mole) of melted 1,6-hexanediamine was added 76.9g of t-butanol half-blocked isophorone diisocyanate. During about a 30-minute addition, the temperature rose to 50-60°C. After an additional one hour of heating at 50-60°C, the oligomer solution was thinned with 40g of 2-hexoxy-ethanol. 

Many papers and patents deal with incorporation of additives in the poly-(urethane-seq-butadiene)s to increase the condensation efficiency, to improve the processing, or to improve the properties of solid propellants. A processing aid, trialkylamine 2201 and also tetracycline 221), was shown to reduce the viscosity and increase the pot life of hydroxytelechelic polybutadiene/polyisocyanate systems. It has been shown that the cure of isophorone diisocyanate and hydroxytelechelic polybutadienes was not affected by the addition of the ammonium perchlorate propellant 222). Special modification of HTPBs have been referred to in Refs. 223 236>. 

Some examples of modified polyisocyanates are isocyanate-terminated quasi-prepolymers (semi-prepolymers), urethane-modified MDI, carbodiimide-modified MDI, isocyanurate-modified TDI, and isocyanurate-modified isophorone diisocyanate. 

Preparation of Integral-Skin Flexible Foams. The major polyisocyanates for use in making integral-skin flexible urethane foams are liquid MDl and TDl prepolymers. In order to make light-stable integral-skin foams, aliphatic diisocyanates, e.g., HDl (hexamethylene diisocyanate) and IPDl (isophorone diisocyanate) in modified forms are used. 

A number of other aliphatic diisocyanates that impart excellent color stability to urethane coatings have been introduced into the U.S. market. Foremost among these are 4,4 -methylene bis(cyclohexyl isocyanate) (H12MDI) and Isophorone diisocyanate (25. 26). An isocyanurate ring containing isocyanate produced by trimerization of IPDI is also commercially available (T-1890). 

In each case, a solution of the desired dlol in 2-hydroxyethyl acrylate was charged to the addition funnel and the isophorone diisocyanate, inhibitor and urethane catalyst were charged to the reaction flask with the water bath in place. The addition took one hour and after a two hour hold at room temperature, the appropriate trifunctional branching agent (TBA) was added. when the amine functional TBA was used, a 50 50 solution of the TBA in the... 

More recent efforts have focused on developments that create true hybrids. For example, blocked isocyanate prepolymers have been mixed with epoxy resins and cured with amines [68-70]. These blocked prepolymers will react initially with the amines to form amine-terminated prepolymers that cross-link the epoxy resin. Several blocked isocyanates are commercially available. The DESMOCAP (Bayer) llA and 12A products are isocyanates (believed to be blocked with nonylphenol) used as flexibilizing agents for epoxy resins. ANCAREZ (trademark. Pacific Anchor, Inc.) 2150 is a blocked isocyanate epoxy blend used as an adhesion promoter for vinyl plastisols. A one-package, heat-cured hybrid adhesive was reported consisting of isophorone diisocyanate, epoxy resin, and a dispersed solid curative based on the salt of ethylenediamine and bisphenol A [71]. Urethane amines are offered commercially that can be used with epoxy resins to develop hybrid adhesive systems [72]. 

Using a mixture of castor oil and hydroxyether of bisphenol-A (HBA) as the polyol and reacting with TDI in the presence of DBTDL catalyst at 35°C, a series of polyurethanes are prepared in an air-circulating oven for 48 h. A series of poly(urethane urea)-vinyl polymer hybrid aqueous dispersions are prepared. Waterborne poly(urethane urea) is synthesised from castor oil and polyoxypropylene polyol M = 1000 g moL ), dimethylol propionic acid and isophorone diisocyanate and then neutralised with tertiary amine. The hybrid aqueous dispersion with high oil content poly(urethane urea) exhibits excellent compressive mechanical strength. Sunflower oil-modified waterborne polyurethane resin may also be prepared. The waterborne resin is synthesised from the monoglyceride of the oU, poly(propylene-ethylene) triol, tartaric acid and toluene diisocyanate, then neutralised with triethyl amine. 

Isophorone diisocyanate (IPDI) n. An isocyanate used in the production of urethane elastomers and foams. It is less volatile than toluene diisocyanate, therefore easier to maintain at low levels in workers airspace and safer to work with. Its structure is modified from that of isophorone, above, in that the oxygen has been replaced by an -N=C=0 group, the double bond is gone, and the top carbon atom in the ring has an additional -CH2N=C=0 linked to it. 

Only the diisocyanates are of interest for urethane polymer manufacture and relatively few of these are employed commercially. The most important ones used in elastomer manufacture are the 2,4- and 2,6-toluene diisocyanates (TDl) 4,4 -diphenylmethane diisocyanates (MDI) and its aliphatic analogue 4,4 -dicyclohexylmethane diisocyanate (Hi2 MDI) 1,5-naphthalene diisocyanate (NDI) 1,6-hexamethylenediisocyanate (HDI) xylyene diisocyanate (XDI), isophorone diisocyanate (IPDI) and 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (TMDI). Also manufactured commercially are various monoisocyanates, including methyl, /7-propyl, /7-butyl, cyclohexyl, phenyl, and 4-chloro- and 3,4-dichlorophenyl isocyanates which are used for substituted ureas and carbamates important as herbicides and crop protection agents. 

Urethane cross-linker Urethane CD-based polymers are obtained by reaction of the CD hydroxyl groups with diisocyanates via polycondensation reaction. The most widely used diisocyanate cross-Unkers are tolylene-2,4-diisocyanate (TDl) and hexamethylene diisocyanate (HDI) [4]. It is also possible to synthesize polymers with specific properties with exotic diisocyanates such as isophorone diisocyanate (IPDI) (Scheme 2.1) [5]. 

Ferreira et al. [75] synthesized a HMA for medical use. Urethanes based on polycaprolactone diol (PCL) were synthesized by reaction of the molecule either with isophorone diisocyanate (IPD-isocyanate) or hexamethylene diisocyanate (HDI-isocyanate). Nies Berthold et al. [76] tried out an adhesive composition based on polymers or polymer blends consisting of caprolactone copolymers or caprolactone copolymers and polycaprolactone. The adhesive can be utilized as HMA for temporarily gluing together biological tissue and other materials in medicine. 

R Lomolder, F Plogmann, P Speier. Selectivity of isophorone diisocyanate in the urethane reaction. Influence of temperature, catalysis and reaction partners. J Coatings Technology 69(868) 51-57, 1997. 

Diamines or diols can be used as chain extenders in copolymerization reactions, but urea linkages formed from diamines often lead to polymer insolubility.(28) Poor solubility is avoided by using diols, but this requires a two stage preparation (Scheme 1) because of the disparity in reactivity of alcohols and amines with isocyanates. To form urea and urethane linkages separately, the reaction between isophorone diisocyanate and benzene dimethanol was carried out first in bulk at 115 °C without catalyst (Equation 1). Secondly, reaction between aminopropyl endcapped dimethylsiloxane oligomers and diisocyanate intermediates was effected in THE at room temperature (Equation 2). Completion of the polymerization reaction was established by NMR and infrared spectroscopy.(8)... 

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