Urethans esters, mixed

Triazolelbenzyltrimethylammonium salt Urethans from mixed carbonic acid esters N-Carbo-ferf-butoxylation... 

Urethans from mixed carbonic acid esters... 

FIGURE 2.27 More on additives. In a carbodiimide-mediated reaction between acid 1 and amine 2, addition of HOObt can lead to the side reaction of aminolysis at the carbonyl of the activating moiety of ester 3, generating addition product 4. Addition of HOBt to a mixed-anhydride reaction containing unconsumed chloroformate generates mixed carbonate 5, leading to production of urethane 6. 

In addition to esterification, these oils can also be reacted with isocyanates to make polyurethanes. Some of the most interesting products to be described below consist of mixed ester-urethane compositions, where the ester portion is made before gelation where the water can be evaporated easily, and the urethane component is added as a type of postcure. 

Because the components must initially form miscible solutions or swollen networks a degree of affinity between the reacting components is needed. Therefore, most of the investigations into epoxy IPNs have involved the use of partially miscible components such as thermoplastic urethanes (TPU) with polystyrenes [57], acrylates [58-61] or esters which form loose hydrogen-bound mixtures during fabrication [62-71 ]. Epoxy has also been modified with polyetherketones [72],polyether sulfones [5] and even polyetherimides [66] to help improve fracture behavior. These systems, due to immiscibility, tend to be polymer blends with distinct macromolecular phase morphologies and not molecularly mixed compounds. 

Morphine also functions as an alcohol, forming a urethane [ii] [417] and other esters. The diacetyl ester [ni, R = R = Ac] (heroin) is obtained by the action of acetic anhydride [349, 418-19], acetylchloride 1387, 420], and ketene [421] on morphine. 3-Acetylmorphine [m, It K R = Ac] results from the partial hydrolysis of heroin [420, 422 4 and from the esterification of morphine with acetic acid [418], Uko lioroin it can be hydrolysed to morphine by adds [418] and enzymes [426], 6-Acetylmorphine [m, R = Ac R = H] is not produced during the hydrolysis of heroin [422-4] but is obtainable by the I CHlwiotod action of acetic anhydride on morphine [418], Other esters Including [rv] [427] and mixed osters aro known [387, 420, 427-36 inc.]. 

Fourier transform infrared microspectroscopy is applied for the characterisation of a coated interface and a polymer blend. The coated sample investigated is prepared by coating a urethane paint on an ethylene-ethyl acrylate copolymer whose ethyl-ester group is partially hydrolysed (EAA/EEA). It is demonstrated that a mixed phase is formed along the coated interface between the paint and the EAA/EEA. Interaction between molecules of the urethane paint and the EAA/EEA is observed. For a polymer blend prepared by mixing PP and polycarbonate. 

Trehalose tetraesters characterised by ID and 2D H and C NMR and ESI-MS as biosurfactants (rather than cryoprotectants) were isolated from a soil strain of Micrococcus luteus. Solubilisation of phenol within mieellar aggregates of hexadecyltrimethylammonium bromide (HTAB) in aqueous solutions were investigated by H NMR in D20. The synthesis and properties of non-cytotoxic carboxymethylcellulose-chitosan hydrogels modified with poly(ester-urethane) was reported. 2D NOE NMR gave new insights into the interactions between polyamidoamine dendrimers and different surfactants including SDS and dodecyltrimethylammonium bromide. The ability of a- and (3-CDs to disrupt a surfactant mixed micelle of an equimolar mixture of octyltriethylammonium bromide (OTEAB) and sodium perfluorooctanoate (SPFO) was studied by H and F NMR. The effect of ethanol on the micellization of SDS (anionic... 

The piperidino-oxycarbonyl group (22), which gives rise to urethanes of a rather different type, has been investigated by Stevenson and Young [146]. These derivatives are stable to aqueous alkali and, unlike the t-alkoxycarbonyl ones, to cold acid (30% hydrobromic acid at room temperature for several hours). They are prepared via the isocyanate esters or the mixed carbonates and may be cleaved by catalytic, electrolytic, or mild chemical reduction with sodium dithionite, etc. 

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