Thermal properties and solubility of ordered aromatic polyamides containing a methyl‐substituted phenylene linkage
01 Dec 1977-Journal of Polymer Science Part A (John Wiley & Sons, Inc.)-Vol. 15, Iss: 12, pp 2997-3008
TL;DR: The thermal properties and solubilities of ordered polyamides and copolyamides were compared with those of the corresponding random polyamide as mentioned in this paper, showing that the latter was less soluble in organic solvents than the latter, depending on the extent of hydrogen bonding of the amide groups.
Abstract: Ordered aromatic polyamides and copolyamides were prepared by the polycondensation of terephthaloyl and isophthaloyl dichlorides with symmetrical diamines containing preformed amide linkages derived from unsymmetrical methyl—substituted aromatic diamines at low temperature. Thermal properties and solubilities of the ordered polyamides were compared with those of the corresponding random polyamides. There was little difference between thermal stabilities of the ordered polyamide and the corresponding random one, while the former was less soluble in organic solvents than the latter, depending on the extent of hydrogen bonding of the amide groups. The thermal stability of the alternating copolyamides containing both terephthaloyl and isophthaloyl groups as acid components was less than that of the corresponding homopolymers having either a terephthaloyl or an isophthaloyl group, and the solubility of the former resembled that of the corresponding ordered homopolysiophthalamides in accord with the extent of hydrogen bonding of the amide groups in both polymers.
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TL;DR: In this paper, the concepts and methodology for sequence control in one-step condensation polymerization are introduced and a brief historical perspective and theoretical aspects of structural regularity of polycondensation are provided.
54 citations
TL;DR: Synthese de tels polyamides, polyesters and polyesteramides influence de la structure moleculaire sur les proprietes optiques et morphologiques as mentioned in this paper.
51 citations
TL;DR: The dyad sequence analysis of Technora (copolyamide prepared from terephthaloyl chloride, p-phenylenediamine, and 3,4‘-diaminodiphenyl ether) was reported using 13C NMR in trifluoromethanesulfonic acid at 100 °C as discussed by the authors.
Abstract: The dyad sequence analysis of Technora (copolyamide prepared from terephthaloyl chloride, p-phenylenediamine, and 3,4‘-diaminodiphenyl ether) was reported using 13C NMR in trifluoromethanesulfonic acid at 100 °C For the detailed peak assignment, some model copolymers were synthesized and the 13C NMR spectra were observed Well-resolved carbonyl carbon peaks of the terephthalic units of Technora were observed, which made it possible to analyze the p-phenylenediamine units and the 3,4‘-diaminodiphenyl ether units at dyad level The information on the head-to-head, tail-to-tail, and head-to-tail sequences of the 3,4‘-diaminodiphenyl ether units was also obtained It was concluded that the sequence of Technora was completely random
12 citations
TL;DR: In this paper, the effect of halogen substituents on both the solubility and the thermal stability of aromatic polyamides has been studied, and new diamine monomers have been synthesized by introducing chlorine groups onto various positions of 4,4'-diaminobenzanilide for the preparation of chlorinated aromatic poly amides.
Abstract: In order to study systematically the effect of halogen substituents on both the solubility and the thermal stability of aromatic polyamides, new diamine monomers have been synthesized by introducing chlorine groups onto various positions of 4,4'-diaminobenzanilide for the preparation of chlorinated aromatic polyamides. The monochlorinated aromatic polyamides, i.e., P-LCl and P-RCl, exhibited liquid crystalline property in 100% sulfuric acid solution in the temperature range from 40 and 60°C. However, the dichlorinated sample, i.e. P-LRCl, did not exhibit the liquid crystalline property due to the bulkiness of two chlorine groups. Both P-LCl and P-RCl exhibited unimodal decomposition behavior in contrast to the chlorinated poly(p-phenylene terephthalamide) (PPTA) that has been known to show bimodal decomposition behavior. The decomposition onset temperature of both P-LCl and P-RCl was 567°C, which was higher than 549°C of unchlorinated polyamide, P-NCl, but the same as that of PPTA. The char yield was about 50% for both P-LCl and P-RCl and higher than 40% of both PPTA and P-NCl. In the case of P-LRCl, the decomposition onset temperature was 480°C, but the highest char yield of 60% was obtained.
9 citations
01 Jan 2012
TL;DR: In this article, the synthesis of sequentially controlled condensation polymers is one of the topics in polymer chemistry and a brief introduction to the topic, including a historical perspective and theoretical aspects is given.
Abstract: The synthesis of sequentially controlled condensation polymers is one of the topics in polymer chemistry. This chapter focuses on and describes concepts and methodologies especially for the sequence control in one-step condensation polymerization. Furthermore, it gives a brief introduction to the topic, including a historical perspective and theoretical aspects. The syntheses of various sequential polymers consisting of (1) symmetric and nonsymmetric monomers, (2) two nonsymmetric monomers, and (3) three nonsymmetric monomers by means of one-stage and of direct methods are all reviewed regarding the structural regularity of polycondensation.
4 citations