Diols dicarboxylic acid anhydride

Activating agents, such as trifluoroacetic anhydride 1,1 -carbonyldiimidazolc carbodiimides sulfonyl, tosyl, and picryl chlorides and a range of phosphorus derivatives can promote direct solution reactions between dicarboxylic acids and diols or diphenols in mild conditions. The activating agents are consumed during the reaction and, therefore, do not act as catalysts. These so-called direct polycondensation or activation polycondensation reactions proceed via the in situ transformation of one of the reactants, generally the carboxylic acid, into a more... 

Polycondensation of a diol with a dicarboxylic acid, either of which may contain a double bond, results in an unsaturated polyester. For this purpose suitable starting compounds are maleic anhydride and 2-butylene-1,4-diol.These can also be used mixed with saturated dicarboxylic acids or diols (copolycondensation) in order to vary the number of double bonds per macromolecule and thereby the properties of the polyester. Unsaturated polyesters are generally prepared by melt condensation.The resulting products are often viscous or waxy substances of relatively low molecular weight. 

Polyesters contain the ester group —COO— in the main chain. Many methods are suitable for their synthesis self-condensation of a,o>-hydroxy acids, ring-opening polymerization of lactones, the polycondensation of dicarboxylic acids with diols, transesterification, the polycondensation of diacyl chlorides with diols, polymerization of O-carboxy anhydrides of a- and jS-hydroxycarboxylic acids, and the copolymerization of acid anhydrides with cyclic ethers. The last reaction is commercially used in the curing of epoxides with anhydrides. 

Polycondensation of diols with derivatives of dicarboxylic acids (e.g., cyclic dicarboxylic acid anhydrides, dicarboxylic acid chlorides, or dicarboxylic acid... 

In 1975, Kellyprepared and characterized a number of polyesters based on 2,5-disubstituted furans in various states of reduction. In this study, 2,5-disubstituted-furan, -dihydrofuran, and -tetrahydrofuran monomers were polymerized using solution, melt-transesterification, ring-opening, and interfacial techniques. These monomers included diacids, diols, diacid chlorides, diesters, dicarboxylic acid anhydrides, as well as monomers based on 5-hydroxymethyl-2-furoic and tetrahydrofuroic acids and esters, and bycyclic lactones containing the tetrahydrofuran ring. A thorough review of previous work done in the area of poljnner synthesis, based on 2,5-disubstituted furan derivatives is reported. It is reported that when... 

Lacfols via lactones, and diols from dicarboxylic acid anhydrides Labeled terpenoids... 

A dispersant that can be used in drilling fluids, spacer fluids, cement slurries, completion fluids, and mixtures of drilling fluids and cement slurries controls the rheologic properties of and enhances the filtrate control in these fluids. The dispersant consists of polymers derived from monomeric residues, including low-molecular-weight olefins that may be sulfonated or phosphonated, unsaturated dicarboxylic acids, ethylenically unsaturated anhydrides, unsaturated aliphatic monocarboxylic acids, vinyl alcohols and diols, and sulfonated or phosphonated styrene. The sulfonic acid, phosphonic acid, and carboxylic acid groups on the polymers may be present in neutralized form as alkali metal or ammonium salts [192,193]. 

Polycondensation of diols with dicarboxylic acids is often performed in the melt. However, it does not always lead to high-molecular-weight polyesters. Sometimes, the starting materials or the resulting polyester are thermally unstable at the high condensation temperatures. If the reactants and the polyester are well soluble, one can carry out the polycondensation in solution (see Example 4-2). The elimination of water from diols and dicarboxylic acids frequently occurs rather slowly. In such cases suitable functional derivatives of the diols and dicarboxylic acids (esters or anhydrides) can be used instead of the direct condensation, as described in Sect. 4.1.1.3. 

The chemical transformation must not affect the stereogenic centers. Suitable acyclic candidates are compounds with easily convertible functional groups, such as diols, diamines, amino alcohols, dicarboxylic acids and so on. A number of procedures known before 1973 have been compiled, including conversion of diols and amino alcohols into sulfites or 1,3-dioxolanes by thionyl chloride, or acetalization with ketones31,1"319, as well as the conversions of dinitriles into imides320, dicarboxylic acids into cyclic anhydrides or imides321, and hydroxy acids into oxazolidones 322. 

Chain Extension of -U-Polystyrene Hiols. A two-stage chain extension of the. -kJ -polystyrene diols was accomplished by carboxylation of the diols with succinic anhydride followed by chain extension with a diepoxide. The succinic anhydride reaction was carried out 120-130°C under nitrogen. The reaction was monitored bj changes in the carbonyl bands at 1715 and 1740 cm in the infrared spectra of the reaction mixtures. The resulting dicarboxylic acid polymers were chain-extended in bulk at 130°C for 9 hours with Sow s HER diepoxide, equivalent weight =171, using bis( 3,5-diisopropylsalicylato)Cr (III) as the catalyst. 

MixedPhosphonate Esters. Unsaturated, mixed phosphonate esters have been prepared from monoesters of 1,4-cyclohexanedimethanol and unsaturated dicarboxylic acids. For example, maleic anhydride reacts with this diol to form the maleate, which is treated with benzenephosphonic acid to yidd an unsaturated product. These esters have been used as flame-retardant additives for thermoplastic and thermosetting resins (97). 

The polyester polyols are obtained by the polycondensation reactions between dicarboxylic acids (or derivatives such as esters or anhydrides) and diols (or polyols), or by the ring opening polymerisation of cyclic esters (lactones, cyclic carbonates). 

A. Reaction Between Dicarboxylic Acids or Anhydrides and Diols... 

Polyesters A broad class of polymers usually made by condensation of a diol with dicarboxylic acid or anhydride. Polyesters consist of chains with repeating carbonyloxy group and can be aliphatic or aromatic. There are thermosetting polyesters, such as alkyd resins and unsaturated polyesters, and thermoplastic polyesters such as PET. The properties, processing methods, and applications of polyesters vary widely. Also called Polyester Resins. 

Synthesis of PEAs by polycondensation has usually been performed by reacting diamide-diol, diester-diamine, ester-diamine, or diamide-diester monomers with dicar-boxylic acid derivatives or diols (Figure 8.1). In addition, a,o)-amino alcohols can be also reacted with acid anhydrides or dicarboxylic acid derivatives. 

Propylene glycol is often used as the diol. To a lesser extent, other glycols, like diethylene glycol, are also used for greater flexibility, or neopentyl glycol for a somewhat better thermal resistance. Bisphenol A (2,2 bis(4-hydroxyphenyl) propane) is used when better chemical resistance is needed. Use of mixed diols is conunon. Many unsafturated dicarboxylic acids can be used, but maleic (as an anhydride) or fumaric acids are the most common. Chloromaleic or chlorofumaric acids are also employed. 

Acetic acid acetic anhydride Pyridazin-3,6-diol ring from dicarboxylic acids... 

Aromatic polyesters were investigated to examine their suitability as a toughening agent for epoxy, and found to be effective for a highly crosslinked system. Liquid rubber is less efficient in toughening a highly crosslinked system. lijima and co-workers [132, 133] synthesised a series of polyesters by the reaction of 1,2 ethane diol and aromatic dicarboxylic acid. The latter and the derivatives contained pthalic anhydride. 

Most hydroxy-terminated polyesters are made by coesterifying two polyols (a diol and a triol) and two diacids (an aliphatic dibasic acid and an aromatic dicarboxylic acid or its anhydride). The ratio of moles of dibasic acid to polyol must be less than 1 so as to give terminal hydroxyl groups and avoid gelation. Molecular weight is controlled by this ratio the smaller the ratio, the lower the molecular weight. The molecular weight distribution Mn, and /n are all controlled by the diol-to-triol ratio. The ratio of aromatic to aliphatic dibasic acids controls Tg of the resin. 

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