Terephthaloyl dichloride

Table 3 demonstrates the influence of the latter factor on the microheterogeneity coefficient (Km) for the case of polycondensation of terephthaloyl dichloride (A) with NMDEA (B) and phenolfluorene (C). This coefficient is computed from the data of H NMR spectra of corresponding copolyesters. It characterizes the relative content of different triades in a copolymer the smaller the Km value, the higher the blockiness of the chains [61]. 

Table 3 Influence of the mode of introduction of reagents into the feed on some properties of triple copolyesters il> prepared from the terephthaloyl dichloride (A), NMDEA (B) and phenolfluorene (C) (the data from [60])...

Terephthaloyl dichloride is distilled in vacuum. Melting point 82-83 °C. 

Acid chloride solution 7.7 g (0.04 mol) of terephthaloyl dichloride are finely powdered in a mortar and dissolved in 40 g of dibutyl phthalate by stirring at 70 °C, taking care to exclude moisture. Dissolution takes about 30 min any insoluble material is filtered off. 

The amine solution (4) is now immediately run in dropwise over a period of 30 s and the stirrer speed reduced to 2000 rpm After 2-3 min the high-speed stirrer is replaced by a normal paddle stirrer and the dispersion stirred (500 rpm) for a further 30 min at room temperature to complete the interfacial polycondensation between terephthaloyl dichloride and diethylenetriamine. 

A mixture consisting of the step 2 product (1.441 mmol), 1,4-terephthaloyl dichloride (1.456 mmol), and 4 ml of CHCI3 were charged into a flask and the milky solution immersed in an ice-salt bath for 15 minutes. This mixture was then treated with... 

Despite their simplicity, neither of these routes have been developed commercially. However, the use of phosgene with carboxylic acids to form acid chlorides has many advantages over the use of PCI 5 or SOClj, in that the by-products (COj and HCI) are readily removed, leaving a high purity product this is especially important in the synthesis of acid chlorides of fatty acids, which resist distiliation [1841a]. Isophthaloyl dichloride and terephthaloyl dichloride are both produced commercially by the action of phosgene on their respective acids [1804a]. 

Thia- and dithiadiamine derivatives were reacted with phthaloyl or terephthaloyl dichloride to form the benzodithiadiaza-crowns (method Z-17) (Voronkov et al., 1979, 1988a, 1988b). The macrocycle containing the phthal-... 

Storbeck and Ballauff prepared polyesters from isohexides and terephthaloyl dichloride by solution polymerization in pyridine, giving colourless, fibrous materials [13]. Isomannide and isoidide yielded semi-crystalline materials however, crystallinity could not be recovered after annealing since their glass transition temperature and melting temperature are too close to each other for them to be crystallized from the melt. Thermogravimetric analysis (TGA) of poly(isosorbide terephthalate) (PIT) showed thermal stability up to 360 °C under a nitrogen atmosphere. 

A high-tenacity aramid yam can be fabricated from a copolymer from 5-(6-amino-2-(/7-aminophenyl)benzimidazole), /7-phenylenediamine, and terephthaloyl dichloride [32]. Also, 2-chloro-p-phenylenediamine and 2-chloroterephthaloyl dichloride can be used. 

What are known as polyhydrazides are produced from terephthaloyl dichloride and p-amino benzhydrazide ... 

The polycondensation of a diol and the diester of a dicarboxylic acid (e.g., the dimethyl ester) can be carried out in the melt at a considerably lower temperature than for the corresponding reaction of the free acid. Under the influence of acidic or basic catalysts a transesterification occurs with the elimination of the readily volatile alcohol (see Example 4.3). Instead of diesters of carboxylic acids one can also use their dicarboxylic acid chlorides, for example, in the synthesis of high-melting aromatic polyesters from terephthaloyl dichloride and bisphenols. The commercially very important polycarbonates are obtained from bisphenols and phosgene, although the use of diphenyl carbonate as an alternative component is of increasing interest (see Example 4.4). Instead of free acids, cyclic carboxylic... 

Terephthaloyl dichloride is distilled in vacuum, Melting point 82-83°C. LiCl is dried in vacuum at 150°C for 24 h. 

In a 250 ml three-necked flask fitted with stirrer and internal thermometer 11.04 g (0.078 mol) of 2-chloro-l,4-phenylenediamine are dissolved in 150 ml dry N,N-dimethylacetamide (containing 2 wt% LiCl). 29.5 ml (0.233 mol) of highly pure trimethylchlorosilane (>99%) are dropped into the solution under stirring at 20°C. Then 15.71 g (0.078 mol) of terephthaloyl dichloride are added, whereupon the temperature and the solution viscosity increase immediately. After 2 h opaque, lytropic liquid crystalline solution is obtained. This solution is poured into a beaker and water is slowly added to the solution, whereupon the polyamide precipitates. It is washed with water to remove the salt-containing solvent. Finally, the product is purified by extraction with propane-2-ol. The polymer is dried in a vacuum oven at 100°C. The polyamide is characterized by determination of the solution viscosity at 20°C (1.25 g of polymer in 50 ml Af-methylpyrrolidone with 2 wt% of LiCl). 

The synthesis of 1,6-diamino-l,6-dideoxy-2,3,4,5-tetra-0-methyl-D-mannitol and its L-iditol analogue from D-mannitol has been described [100], These diamines, containing a two-fold axis, gave stereoregular AABB polyamides on polycondensation with terephthaloyl dichloride and dipentachlorophenyl esters, or dichlorides of aliphatic dicarboxylic acids, in solution or under interfacial polycondensation conditions [99, 109]. In spite of the regioregularity present in the polymeric chains, these optically active polyamides could not be crystallized. 

Similarly, terephthaloyl dichloride (4b) and 1,4-diethynylbenzene (5g) can be appbed in a pseudo five-component reaction to synthesize the corresponding p-phenylene-bridged derivatives 48 and 49 in moderate to good yields (Scheme 29). 

A similar strategy was employed to synthesize poly(arylene thiopheny-lene) 50 in a one-pot three-component tandem polymerization. The polymerization of terephthaloyl dichloride, l,2-bis(4-ethynylphenyl)-1,2-diphenylethene, and 2-mercapto acetate proceeds smoothly under the previously reported mild reaction conditions to afford the desired polymeric structure in excellent yields (up to 97%) and high molecular weights of up to 156,000. Interestingly, a strict stoichiometry of the starting materials is not required (Scheme 30) (2014MM(47)4920). 

Polycondensation of p-phenylenediamine with terephthaloyl dichloride produces aromatic polyamides, which display liquid-crystal characteristics. The spinning of these polymers from hexamethylphosphoramide or sulfuric acid solution yields high-value aramid fibers (Kevlar Du Pont), Twaron Akzo) which are distinguished by their high temperature resistance (see Chapter 7.3.1). 

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