Alkoxylation Isocyanate

Izumi used Pd(OAc)2 to effect the bis-alkoxylation of o-nitrostyrenes to form the corresponding o-nitrophenylacetaldehyde acetals, which, upon treatment with Fe/HOAc/HCl, give a variety of indoles (4-OMe, 5-OMe, 4-Me, 4-C1, 4-C02Me, 6-Me) in 63-86% yields [465]. Mori and coworkers employed a titanium-isocyanate complex to construct tetrahydroindolones 373 from cyclohexane-1,3-diones [466],... 

Reactions of alkoxylated lignin with diisocyanates produce thermoset materials because the lignin polyol is always polyfunctional with a functionality greater than 2. The isocyanate-alcohol reaction produces a urethane linkage that when repeated creates a crosslinked, nonreformable polyurethane. This is shown in Fig. 6. A broad spectrum of lignin-based urethanes have been made and tested. The data show that these materials match if not exceed the properties of synthetic polyurethanes made without lignin [60]. 

Step polymers can be reacted with alkoxylignin to form alko lignin esters, thermodynamic and equilibrium forces dictate that the best products from this chemistry will come from step- reaction polymers capped with isocyanate groups. New products of alkoxylated lignin covalently bonded to cellulose acetate or caprolactam are known and are available tor utilization. 

Hydroxyl Acrylic Resins [13] AJlyl alcohol and allyl alkoxylate have l n incorporated into hydroxyl acrylic resins to provide the pendant hydroxyl groups for crosslinking reaction. The resins are crosslinked with melamine or an isocyanate to form acrylic-melamine coatings or acrylic-polyurethane coatings, respectively. The coatings can be used as automotive topcoat or other high performance industrial coatings. 

P. are prepared by - alkoxylation of the starting polyols with ethylene oxide or propylene oxide. The length of the polyether chains is regulated by the amount of alkylene oxide and the reaction time (acidifying). The kind of isocyanate and the structure of the p. command the properties and the uses of the resulting polyurethanes ... 

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