Alcohols anhydrides

The sugar alcohol anhydride polygalitol, 1,5-anhydro-D-glucitol, may be prepared from the root of Poly gala Senega L.49 The process is, however, a time-consuming one and chemical synthesis of the substance by Raney... 

It is probable that on addition of a carboxylic acid to the alcohol/anhydride mixture trifluoroacetic acid is formed, together with a mixed anhydride that is either highly polar or actually ionised to give an acylium ion in solution (Figure 8.7). 

Table 5.23. Graft copolymer formation in binary PEST/PO blends by alcohol + anhydride reaction...

Studies have been made of PEST/PO/styrene copolymer blend compatibilization in which a copolymer may be formed between polyester alcohol end-groups and pendent anhydride functionality on a styrene copolymer (Table 5.27). Because the alcohol-anhydride reaction is reversible (with the equilibrium lying on the side of unreacted anhydride), only a relatively small amount of copolymer may be formed. In consequence, the dispersed phase polymer may not be well stabilized against coalescence upon further thermal treatment [Sun et al., 1996]. Alternatively, at least some copolymer may be formed by a degradative mechanism through transesterification between PEST main-chain linkages and a low concentration of pendent acid groups in anhydride-functionalized styrene copolymer (see Section 5.7.12.5). 

These compounds contain the characteristic ether linkage C-O-C, and can be thought of either as alcohols in which the hydrogen atom of the hydroxyl group is replaced by an alkyl group, or as alcohol anhydrides . Diethyl ether and some other ethers are made by a dehydration reaction ... 

Copolymer Formation by Alcohol + Anhydride or Carboxylic Acid Reaction... 

The epoxy adhesives produce, with limited contraction, joints whose main characteristic is an absence of creep at high temperatures (mechanical strength is maintained up to temperatures of 100-150° C). Epoxy groups exhibit a high reactivity with many antagonistic functions, mainly amines, but also alcohols, anhydrides, and carboxylic acids (O Fig. 14.14). 

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