Polyester A condensation

Polyester. A condensation polymer formed by the reaction between a polyhydric alcohol and a polybasic acid, as the polymeric product resulting from the reaction of glycerol and phthallic acid or anhydride. 

Polyester, a condensation polymer, can be produced by chainwise, acid-catalyzed ring openings of cyclic ester (lactone) without expulsion of small molecules, and also by stepwise polycondensation of ohydroxycarboxylic acid. 

LRC-100Finish. The use of LRC-100 flame retardant for 50/50 polyester cotton blends has been reported (144). It is a condensation product of tetrakis(hydroxymethyl)-phosphonium salt (THP salt) and A/A7,A7 -trimethylphosphoramide [6326-72-3] (TMPA). The precondensate is prepared by heating the THP salt and TMPA in a 2.3-to-l.0-mole ratio for one hour at 60—65°C. It is appUed in conjunction with urea and trimethylolmelamine in a pad-dry-cure oxidation wash procedure. Phosphoms contents of 3.5—4.0% are needed to enable blends to pass the FF 3-71 Test. 

This particular polymer is a fibre-forming material (Perlon U). Although in many respects this reaction resembles the formation of polyesters and polyamides it is not a condensation reaction but involves a transfer of hydrogen atoms and thus may be considered as an example of rearrangement polymerisation. 

Although no small molecule gets eliminated, the reaction can be considered a condensation polymerization. Monomers suitable for polymerization by ring opening condensation normally possess two different functional groups within the ring. Examples of suitable monomers are lactams (such as caprolactam), which produce polyamides, and lactons, which produce polyesters. 

Adipic acid, 219.2 g (1.5 mol), and 77.6 g (1.25 mol) of 1,2-ethanediol are weighed into a 500-mL glass reactor equipped with a mechanical stirrer, a nitrogen inlet, and a distillation head connected to a condenser and a receiver fiask. The reactor is placed in a salt bath preheated at 180°C and the temperature is dien raised gradually to 220°C (see note at end of procedure) until the greater part of water has been removed (3 h). The reactor is cooled down to 160°C and vacuum is applied slowly to ca. 0.07 mbar (30 min). Temperature is ramped to 220°C (see note below) at a rate of l°C/min and reaction is continued for an additional 90 min. At the end of reaction, the carboxylic acid endgroup content is close to 1.90 mol/kg. No purification of final polyester is carried out. 

To a stainless steel reactor equipped with a heating mantle, a charging port, a condenser for removing ethylene glycol, an inert gas inlet, and a sampling valve were added 400 g of bis(2-hydroxyethyl)terephthalate, 136 g of ethylene glycol, and 0.035 g (or 0.225 g) of sodium acetate trihydrate. The temperature was raised to between 190 and 200°C in 1 h and then 454 g of waste polyester... 

Unsaturated polyesters were obtained by reacting the glycolyzed product widi maleic anhydride at a hydroxy-to-carboxyl ratio of 1 1. The hydroxyl number was determined without separation of die free glycol. The polyesterification reaction was conducted in a 2-L round-bottom dask equipped with a condenser, a gas bubbler, a thermowell, and a stirrer. The reaction mixture was heated from room temperature to 180°C in about 1-1.5 h. The temperature was maintained at 180°C for about 3 h, dien raised to 200°C and maintained until die acid value reached 32 mg KOH/g. 

STRATEGY (a) Look at the backbone of the polymer, the long chain to which the other groups are attached. If the atoms are all carbon atoms, then the compound is an addition polymer. If ester groups are present in the backbone, then the polymer is a polyester and the monomers will be an acid and an alcohol. If the backbone contains amide groups, then the polymer is a polyamide and the monomers will be an acid and an amine, (b) If the monomer is an alkene or alkvne, then the monomers will add to one another a Tr-bond will be replaced by new cr-bonds between the monomers. If the monomers are an add and an alcohol or amine, then a condensation polymer forms with the loss of a molecule of water. 

The most common form of step growth polymerization is condensation polymerization. Condensation polymers are generally formed from simple reactions involving two different monomers. The monomers are difunctional, having a chemically reactive group on each end of their molecules. Examples of condensation polymerization are the formation of nylon 66, a polyamide, and of poly(ethylene terephthalate), a polyester. Because condensation poly-... 

Polyesters may be used [27-30,223] instead of a fatty acid modifier for imidazoline. Thus a corrosion inhibitor with film-forming and film-persistency characteristics can be produced by first reacting, in a condensation reaction, a polybasic acid with a polyalcohol to form a partial ester. The partial ester is reacted with imidazoline or fatty diamines to result in a salt of the ester. Oil-soluble, highly water-dispersible corrosion inhibitor or oil-dispersible. 

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... 

The trade name of a polyester fibre used as textile reinforcement for mbber in products such as tyres, belting and hose. It is a truly synthetic fibre made from polyethylene terephthalate, a condensation product of terephthalic acid and ethylene glycol. 

The chemicals used in syntheses were used as received from the supplier. The unsaturated polyesters were prepared by standard methods from the diacids and diols using butyl stannoic acid (Fascat 4100) as the catalyst. The water of condensation removed using a xylene azeotrope and after reaching the desired acid value the xylene was removed by distillation. The synthesis of unsaturated polyester A is representative. 

Synthesis of Unsaturated Polyester A. The unsaturated polyester oligomer A was prepared in a 500 milliliter 4-neck flask fitted with a variable speed stirrer, a heating mantle, a gas inlet tube, a thermometer, a Dean-Starke trap and a condenser. The flask was charged with 147.0 g (1.5 mol) of maleic anhydride (Amoco), 195 g (1.88 mol) of 1,5-pentane diol (BASF), about 35 ml of xylene and 0.3 g of Fascat 4100. Then heated slowly under a nitrogen blanket to 175° C while the water of condensation was removed... 

Some other example of condensation polymers are Dacron (a polymer of ethylene glycol), polyester (a polymer of p-terephthalic acid), Bakelite (a polymer of phenol and formaldehyde). 

The resultant molecule is a polymer held together by many ester groups. Such a polymer is a polyester. The linkage through multiple condensation reactions results in a condensation polymer. 

Classify each polymer as an addition polymer (formed by addition polymerization) or a condensation polymer (formed by condensation polymerization). Then classify each condensation polymer as either a polyester or a nylon (polyamide). 

Prior to polymerization, p-xylene is first oxidized to terephthalic acid (TA) or dimethyl terephtalate (DMT). These diacid or dimethyl ester monomers are then polymerized via a condensation reaction with ethylene glycol to form the polyester. Prior to the development of a method to purify TA to make purified terephtahc acid (PTA, >99% pure) by the Mid-Century Corporation in the 1950s [10], DMT was the primary way to obtain the purified dicarboxylate. The Amoco Oil Company, now part of BP International, made several improvements to the PTA process since its inception [11]. Since the advent of the availability of PTA, it has become the monomer of choice over DMT. PTA avoids the complications of including methanol to enable purification and handling the methanol evolved during the polymerization to polyester. 

Knani D, Gutman AL, Kohn DH (1993) Enzymatic polyesterification in organic media. Enzyme-catalyzed synthesis of linear polyesters. I. Condensation polymerization of linear hydroxyester. II. Ring-opening polymerization of e-caprolactone. J Polym Sci A Polym Chem 31 1221-1232... 

The polymers can be categorised as formaldehyde containing and formaldehyde free and as thermoset or thermoplastic resins. Typical formaldehyde containing resins are melamine formaldehyde sulfonamide resins, where the sulfonamide is ortho and para toluenesulfonamide. The sulfonamide, which is a solvent for the dye, undergoes a condensation polymerisation with formaldehyde and melamine, the latter acting as a cross-linking agent. Non-formaldehyde, thermoplastic resins are usually polyamides and polyesters. 

There are two types of cure reactions of thermosetting resins step (e.g., epoxies, phenolics, urethanes) and chain (e.g., unsaturated polyesters, vinyl esters, acrilates) polymerizations. In the first type, the size of the polymer chain increases because of the linking of the oligomers (e.g., monomers, dimers, etc.) to themselves. Short chains can be linked to long ones in a condensation reaction. In the second case, the size of the polymer chain increases because of... 

Block copolymers may also be made by condensation polymerization. Elastomer fibers are produced in a three-step operation. A primary block of a polyether or polyester of a molecular weight of 1000-3000 is prepared, capped with an aromatic diisocyanate, and then expanded with a diamine or dihydroxy compound to a multiblock copolymer of a molecular weight of 20,000. The oxidative coupling of 2,6-disubstituted phenols to PPO is also a condensation polymerization. G. D. Cooper and coworkers report the manufacture of a block copolymer of 2,6-dimethyl-phenol with 2,6-diphenylphenol. In the first step, a homopolymer of diphenylphenol is preformed by copper-amine catalyst oxidation. In the second step, oxidation of dimethylphenol in the presence of the first polymer yields the block copolymer. 

Polyurethanes (PU) are a special class of polymers containing the urethane group, (—NH-CO-O-), commonly prepared by a condensation reaction between a diisocyanate and a diol, such as hydroxyl terminated polyether or polyester ... 

Note that the polymerizations of lactones and lactams give polyesters and polyamides, respectively, polymers that can also be synthesized by conventional step-growth polymerization from noncyclic monomers. Although the polymer prepared from cyclic monomers looks like a condensation polymery in strict terms it is not, because no small-molecule byproduct was pro-... 

Polyester. Polyester is made by the polymerization reaction of a diol and a diester. The main commercial polymer is formed by a condensation reaction using ethylene glycol and terephthalic acid. Fibers are formed by meltspinning. Commercially introduced in 1953 by the DuPont Company as Dacron, polyester fibers have high strength, and very low moisture absorbance. The fiber is usually spun with a round cross section. Polyester is the most-used synthetic fiber around the world. 

The reaction of silicon tetrachloride with polyliydric alcohols produces a condensation polymer which may be called a silicon polyester. Some interesting condensation polymers related to these are produced by the reaction of ethyl silicate with glycols and phenols.40... 

Polycondensation. A condensation reaction which yields a polymeric substance as one of the products. See Condensation, Polyester. 

Having given you a very crude picture of what happens in a condensation reaction, let us now turn our attention to making a polymer, a polyester. The question is this if we heat acetic acid and ethanol up to just over 100°C, to get the reaction going and drive off water, why don t we form polymer The answer is simple once you react each functional group, the acid and the alcohol, that s the end of it, because the methyl groups don t react under these conditions, nor (under other conditions) in such a way as to lead to the formation of a polymer. Obviously, to make linear chains we need bifunctional molecules, as illustrated in Figure 3-4, where we use the letters A and B to represent... 

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