Dicarboxylic acids polyesters

Polyesters from diols and dicarboxylic acids (polyester fibres). 

Transesterification -dialcohol + diester -dialcohol + dicarboxylic acid Polyesters... 

Keywords enzymatic polymerization, dicarboxylic acid, polyester... 

Eastman PA-l-2CNCp is a cyclohexane dimethanol, neopentyl glycol, 1,6 hexane diol, isophthalic acid, terephthalic acid, 1,4-cyclohexane dicarboxylic acid polyester of acid value 4 and 60% solids in Solvesso 150 solvent. The formulation is available from Eastman Chemical (publication N-330B). Eastman C-11 ketone is a ketone solvent blend with BR 200-240 °C supplied by Eastman Chemical. 

Other polyesters that have been studied include hydroxy branched polyethers [20], methacrylic trimers [9], bntyl acrylate, methylmethacrylate and polyesters [21], and diol-dicarboxylic acid polyesters [22]. 

Polyesters are a second class of condensation polymers and the principles behind their synthesis parallel those of polyamides Ester formation between the functional groups of a dicarboxylic acid and a diol... 

Polycarbonates. Polyarjiates are aromatic polyesters commonly prepared from aromatic dicarboxylic acids and diphenols. One of the most important polyarylates is polycarbonate, a polyester of carbonic acid. Polycarbonate composite is extensively used in the automotive industry because the resin is a tough, corrosion-resistant material. Polycarbonates (qv) can be prepared from aUphatic or aromatic materials by two routes reaction of a dihydroxy compound with phosgene accompanied by Hberation ofHCl(eq. 5) ... 

As with poly(ethylene terephthalate) PBT-based copolymers have been introduced to overcome some of the deficiencies of the homopolymer. For example, the rather low notched impact strength of unreinforced grades has been overcome by partial replacement of the terephthalic acid with a longer chain aliphatic dicarboxylic acid. Improved toughness has also been obtained by grafting about 5% of ethylene and vinyl acetate onto the polyester backbone. 

With a somewhat lower level of heat resistance but with many properties that make them of interest as engineering materials alongside the polycarbonates, polysulphones, poly(phenylene sulphides) and polyketones are the so-called polyarylates which are defined as polyester from bis-phenols and dicarboxylic acids. 

Plasticizers can be classified according to their chemical nature. The most important classes of plasticizers used in rubber adhesives are phthalates, polymeric plasticizers, and esters. The group phthalate plasticizers constitutes the biggest and most widely used plasticizers. The linear alkyl phthalates impart improved low-temperature performance and have reduced volatility. Most of the polymeric plasticizers are saturated polyesters obtained by reaction of a diol with a dicarboxylic acid. The most common diols are propanediol, 1,3- and 1,4-butanediol, and 1,6-hexanediol. Adipic, phthalic and sebacic acids are common carboxylic acids used in the manufacture of polymeric plasticizers. Some poly-hydroxybutyrates are used in rubber adhesive formulations. Both the molecular weight and the chemical nature determine the performance of the polymeric plasticizers. Increasing the molecular weight reduces the volatility of the plasticizer but reduces the plasticizing efficiency and low-temperature properties. Typical esters used as plasticizers are n-butyl acetate and cellulose acetobutyrate. 

Polyesters can be produced by an esterification of a dicarboxylic acid and a diol, a transesterification of an ester of a dicarboxylic acid and a diol, or by the reaction between an acid dichloride and a diol. 

For this use, the preferred powders are based on acrylic, epoxy or polyester and epoxy resins. For best colour, epoxy resins are crosslinked with anhydrides of dicarboxylic acids in the straight epoxy coatings, or with saturated polyesters of high acid content in the epoxy-polyester type. Acrylics contain epoxide rings via, for example, glycidyl methacrylate (CH2=C(CH3) —CO—O—CHj—CH —CH2), and these groups crosslink... 

Most of these furan polycondensates are more sensitive to thermal and oxidative degradation than their benzene counterparts. Particularly affected are the polyesters obtained from 2,5 -fci sfhydroxymethyl) furan indicating that one of the vulnerable groups must be the -Fu—CH2—0-, and not the -Fu—CO—O-, since polycondensates obtained from 2,5-dicarboxylic acid are more stable, as expected from the... 

Many other reactions have been reported for the synthesis of polyesters, such as reactions between dicarboxylic acid salts and dialkyl halides, reactions between... 

Trinitrochlorobenzene (piciyl chloride) in pyridine-A -mcthylpyrrolidi-none (NMP) solutions were later used for the preparation of polyesters from dicarboxylic acids and diphenols or aliphatic diols,309 but better results have been obtained with sulfonyl chlorides and phosphorus compounds. 

Hie reaction of dicarboxylic acid cesium or potassium salts with alkylene dihalides is another method of polyester preparation in relatively mild conditions... 

Polyester polyols (Scheme 4.4) are prepared by condensation polymerization of dicarboxylic acids and diols. An excess of diol ensures OH functional product, minimizing die possibility of residual acid groups which react with isocyanates to generate C02 and act as inhibitors in catalyzed urethane reactions. The reactants are heated at 200-230°C under vacuum to remove the water by-product and drive the reaction to completion. The most common coreactants include adipic... 

Dicarboxylic acids or esters thereof are recovered from solid phase polyester materials, such as post-consumer products and factory scrap, by subjecting the polyester to at least two hydrolysis stages in at least the first of which the amount of water used is substantially less than needed to effect total conversion of the polyester to the dicarboxylic acid. Also the diol content is controlled in the course of carrying out the hydrolysis. The hydrolysis reactions may be preceded by reaction of the polyester with a diol, the resulting depolymerisation products then being hydrolysed. 

Polycondensation of dicarboxylic acid derivatives and glycols to polyesters... 

So far, various dicarboxylic acid derivatives, dicarboxylic acids, their activated and non-activated esters, cyclic acid anhydrides, and polyanhydrides have been polymerized with glycols through lipase catalysis to give polyesters. 

Long-chain unsaturated a,oo-dicarboxylic acid methyl esters and their epox-idized derivahves were polymerized with 1,3-propanediol or 1,4-butanediol in the presence of lipase CA catalyst to produce reachve polyesters. The molecular weight of the polymer from 1,4-butanediol was higher than that from... 

A novel chemoenzymatic route to polyester polyurethanes was developed without employing highly toxic isocyanate intermediates. First, diurethane diols were prepared from cyclic carbonates and primary diamines, which were subsequently polymerized with dicarboxylic acids and glycols by using lipase CA as catalyst, yielding the polyurethanes under mild reaction conditions. 

Polymerisation of a diol with a dicarboxylic acid is exemplified by the production of a polyester from ethylene glycol and terephthalic acid either by direct esterification or by a catalysed ester-interchange reaction. The resulting polyester Terylene) is used for the manufacture of fibres and fabrics, and has high tensile strength and resiliency its structure is probably ... 

Branched polyesters contain oxalkylated primary fatty amines or oxalkyl-ated polyamines together with at least trivalent oxalkylated alkanol that is responsible for branching. The condensation is achieved with a dicarboxylic acid or a dicarboxylic acid anhydride [216]. In this way, branched polyoxyalkylene mixed polyesters are formed. Suitable solvents are water or organic solvents, such as methanol, isopropanol, butanol, or aromatic hydrocarbons (e.g., toluene, xylene). 

If the carboxylic acid has two carboxyl functional groups (a dicarboxylic acid) and if the alcohol has two hydroxyl functional groups (a diol), a polyester will result nHOOC—R—COOH + nHO—R —OH —> +OOC—R—COO—R +n + nH20. 

Esterification of a dicarboxylic acid such as terephthalic acid via the diimidazolides with diols readily leads to the corresponding polyesters.[12]... 

Polyesters form via a condensation reaction between a dicarboxylic acid and a dialcohol to create an ester linkage, as shown in Fig. 24.1. By far, the two most common polyesters are polyethylene terephthalate and polybutylene terephthalate, the chemical structures of which are shown in Fig. 24.2. These two polymers differ from one another by the length... 

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