Urethanes reaction with alkylene oxides

Virtually all of the organo derivatives of CA are produced by reactions characteristic of a cycHc imide, wherein isocyanurate nitrogen (frequendy as the anion) nucleophilically attacks a positively polarized carbon of the second reactant. Cyanuric acid and ethylene oxide react neady quantitatively at 100°C to form tris(2-hydroxyethyl)isocyanurate [839-90-7] (THEIC) (48—52). Substitution of propylene oxide yields the hydroxypropyl analogue (48,49). At elevated temperatures (- 200° C). CA and alkylene oxides react in inert solvent to give A/-hydroxyalkyloxazohdones in approximately 70% yield (53). Alternatively, THEIC can be prepared by reaction of CA and 2-chloroethanol in aqueous caustic (52). THEIC can react further via its hydroxyl fiinctionahty to form esters, ethers, urethanes, phosphites, etc (54). Reaction of CA with epichlorohydrin in alkaline dioxane solution gives... 

Propylene Oxide. Propylene oxide is another basic chemical used in manufacturing intermediates for urethane foams (cushioning and insulation), coatings, brake fluids, hydraulic fluids, quenchants, and many other end uses.23 The classic industrial synthesis of this chemical has been the reaction of chlorine with propylene to produce the chloro-hydrin followed by dehydrochlorination with caustic to produce the alkylene oxide, propylene oxide, plus salt. 

The reaction of starch with bis(hydroxymethyl)ethyleneurea condensed with cationic poly(urea amides) and cationic polyamides was used to produce paper sizes, adhesives, and textile-finishing agents.2616 Cationic starch that has been prepared from starch and cyanamide was patented for sizing wood and for synthetic wool fibers and fabrics.2296,2298,2662 Reaction of starch urethanes with alkylene oxides and aldehydes was reported for use as hardenable compounds in waterproof films, coatings, and adhesives.2663... 

The scission of urethane groups is explained by the following two consecutive reactions (20.13 and 20.14). The first reaction is the addition of alkylene oxide to the active hydrogen of urethane groups (20.13). The resulting hydroxyalkyl urethane, by an intramolecular transesterification, leads to the splitting of the urethane bonds of PU, the PU network is destroyed with the formation of an oxazolidone and a polyether polyol. 

Chemical modifications may also include the derivatization of starch by reaction of its hydroxyl groups with alkylene oxides. Other suitable substances are such that form ether linkages, ester linkages, urethane linkages, carbamate linkages, or isocyanate linkages. The degree of substitution of the chemically modified starch varies from 0.05 to 0.2. 

ASTM D2849-69, Standard Methods of Testing Urethane Foam Polyol Raw Materials, describes a number of tests used for analyzing poly(alkylene oxide)s (1). These tests include metals analysis, acid and hydroxyl numbers, unsaturation values, water, suspended matter, specific gravity, viscosity, and color. Many of these tests are well known and will not be described. Those tests dealing with end groups—i.e., the functional groups that are used in the further reaction of poly(alkylene oxide)s—are discussed below. Detailed test procedures can be found in the cited reference and also can be obtained from poly(alkylene oxide) suppliers. 

---