Terephthaloyl chloride diamine polycondensation

The polyamide-hydrazide 7 was prepared by solution polymerization in anhydrous dimethylacetamide from terephthaloyl chloride and p-amino-benzhydrazide at ca. 10 °C. The polyamide 8 resulted from the polycondensation of m-phenylenediamine with isophthaloyl chloride at —20 °C, whereas 9 was prepared by the reaction of terephthaloyl chloride with the complex diamine l,3-bis(3-aminobenzamide)benzene at —20 °C. The water flux and salt rejection through these membranes were summarized in Table 5. The polyamide-hydrazide (7) membranes were prepared from polymer solutions containing 6 7% polymer (Mv 3 34,000) by casting on glass plates. The material was placed in an oven for 30 60 min and coagulated in deionized... 

Poly(p-phenylene terephthalamide) PPD-T, also called para-aramid, can be polymerized to a fiber-forming molecular weight by polycondensation of terephthaloyl chloride and 1,4-phenylene diamine. 

Lu et al. [2] fabricated TFC NF membranes, in which the skin layer was either polyesters or polyamides. The monomers used in the polycondensation reactions are as follows (1) alcohol (bisphenol-A, BPA), (2) amine (metaphenylene diamine and piperazine), and (3) acid chloride (isophthaloyl chloride, terephthaloyl chloride [3,4], and trimesoyl chloride). They reported that the composite layer (active layer) was smoother than that of the substrate membrane. Upon formation of the active layer, the pore size decreased, which resulted in a flux decrease and a retention increase. Although it is unclear, they seem to maintain that their results confirm Hirose et al.s conclusion, i.e., the flux increases with an increase in surface roughness [Ij. 

With a few exceptions, interfacial polycondensation has remained a laboratory method for the synthesis of polymers, since diacyl chlorides are too expensive for commercial production. The exceptions include the polycondensation of bisphenols with phosgene (see Section 26.5.1) and the synthesis of aromatic polyamides, from m-phenylene diamine, isophthaloyl chloride, and terephthaloyl chloride (Section 28.2.4). The method is also used to give wool a fluff-free finish by producing a polycondensate from sebacoyl chloride and hexamethylene diamine on the wool fiber. 

Aramid Fibers. Aramid (aromatic polyamide) fibers such as Kevlar (DuPont) and Twaron (Akzo Nobel) are made of poly(paraphenylene terephthala-mide). The polymer can be prepared by solution polycondensation of p-phenylene diamine and terephthaloyl chloride at low temperatures. The fiber is spun by extrusion of a solution of the polymer in a suitable solvent (for example, sulphuric acid), followed by stretching and thermal annealing treatment. Tech-nora (Teijin) fibers are slightly different from Kevlar and Twaron as they consist of a copolymer poly(paraphenylene terephthalamide-co-3,4-oxydiphenylene terephthalamide). Various grades of Kevlar fibers are produced (Kevlar-29, 49, and 149), Kevlar-49 being the one more commonly used in composite structures. 

Poly(l,4-benzamide) (I, PBA) is most commonly prepared by low-temperature solution polycondensation of 4-aminobenzoyl chloride hydrochloride. Poly(l,4-phenylene terephthalamide) (II, PPTA), which is the aramid that has become of prime commercial importance, t5 ically is s)mthesized by solution polycondensation of terephthaloyl chloride and 1,4-phenylene diamine (1-3 see also references 4 and 5 for excellent reviews of the polymerization and processing of aramids). 

---