Polyamides Phenyl-substituted

Goyal and co-workers [10] in their Fourier-transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) investigation of the thermal stability of N-phenyl substituted aromatic-aliphatic and of aromatic amides derived from 4,4-dianilodiphenyl showed that the aromatic-aliphatic polyamides had glass transition temperatures in the range 76-116 °C, whilst the aromatic polyamides had transition temperatures of 207-255 °C. The polymers were thermally stable, and had decomposition temperatures in excess of 400 °C in air. 

A. Singh, K. Ghosal, B.D. Freeman, A.E. Lozano, J.G. de la Campa, J. de Abajo, Gas separation properties of pendant phenyl substituted aromatic polyamides containing sulfone and hexafluoroisopropylidene groups. Polymer 40 (20)(1999) 5715-5722. 

Similarly, the five-membered phenyl-substituted and nitrogen analogue monomers yield the corresponding polyester and polyamide. 

Tg measurements have been performed on many other polymers and copolymers including phenol bark resins [71], PS [72-74], p-nitrobenzene substituted polymethacrylates [75], PC [76], polyimines [77], polyurethanes (PU) [78], Novolac resins [71], polyisoprene, polybutadiene, polychloroprene, nitrile rubber, ethylene-propylene-diene terpolymer and butyl rubber [79], bisphenol-A epoxy diacrylate-trimethylolpropane triacrylate [80], mono and dipolyphosphazenes [81], polyethylene glycol-polylactic acid entrapment polymers [82], polyether nitrile copolymers [83], polyacrylate-polyoxyethylene grafts [84], Novolak type thermosets [71], polyester carbonates [85], polyethylene naphthalene, 2,6, dicarboxylate [86], PET-polyethylene 2,6-naphthalone carboxylate blends [87], a-phenyl substituted aromatic-aliphatic polyamides [88], sodium acrylate-methyl methacrylate multiblock copolymers [89], telechelic sulfonate polyester ionomers [90], aromatic polyamides [91], polyimides [91], 4,4"-bis(4-oxyphenoxy)benzophenone diglycidyl ether - 3,4 epoxycyclohexyl methyl 3,4 epoxy cyclohexane carboxylate blends [92], PET [93], polyhydroxybutyrate [94], polyetherimides [95], macrocyclic aromatic disulfide oligomers [96], acrylics [97], PU urea elastomers [97], glass reinforced epoxy resin composites [98], PVOH [99], polymethyl methacrylate-N-phenyl maleimide, styrene copolymers [100], chiral... 

Hie reaction of a diamine with a diester under anhydrous conditions is reasonably rapid. However, a side reaction at high temperatures (>200°C) is N-substitution. Unfortunately, this N-substitution is particularly strong with methyl esters,28 37 65 and therefore, methyl esters such as dimediyl terephthalate or dimedryl isoph-thalate cannot be used for thermal polyamidations. Other esters, such as ethyl, butyl, and phenyl ester, do not seem to have this problem. 

Recent developments in the substitution of completely aromatic LC polyesters have produced polymers which show improved solubilities and reduced transition temperatures (29). The presence of these side groups provides a method for producing polymers that are compatible with other similarly modified polymers. In this way, blends of rigid and flexible polymers can be prepared. Substituents have included alkyl, alkoxy (30) and phenyl alkyl groups (21), some of which lead to mesophases that have been reported as being "sanidic" or board-like. This approach has been used with both polyesters and polyamides and has lead to lyotropic and thermotropic polymers depending on the particular composition used. Some compositions even show die ability to form both lyotropic and thermotropic mesophases (22). 

MXD6 and PA-61, respectively, show different miscibility, e.g., with aliphatic PA s. Clearly, blind application of the segmental interaction strategy to aromatic or semi-aromatic polyamides could lead to conflicts. However, the problem can be resolved considering p and m substituted phenyl as two different statistical segments [Ellis, 1995]. This idea is indeed evident in the segmental contributions listed in Table 2.11. 

The introduction of alkyl groups onto the benzene rings of aromatic polyamides has proved to impart higher solubility to the polymers. The thermostability of these however is reduced because of insufficient resistance of the alkyl substituents towards oxidation. Some studies have therefore been carried out using aromatic substituted monomers, for instance, phenyl [27], phenoxy and thio-phenoxy [28] substituted diamines, and phenyl [27, 29, 70] and phenoxy [30] substituted diacids. These have been used to prepare polyamides 15. In Table 4... 

Let us now consider the structural organization of polyesters and polyamides with alkyl chains [30]. These systems are similar to alkyl-substituted PT and PANi/surfactant. The results obtained for these polymers would be applicable to conducting polymers that also have an aromatic backbone. In the crystalline state, structures of polyesters based on 1,4-dialkyl esters of pyromellitic acid and 4,4 -biphenol (PE-1) were found to depend on the length of the alkyl chains. For n = 12 a layered structure was detected with an interchain distance within layers of 4.55 A. For n = 14, 16, and 18 the interchain distance was 3.45 A. This distance corresponds to the van der Waals radius of the phenyl ring. Such dense packing requires a coplanar arrangement of the aromatic backbone within layers. Coplanar... 

The reaction of 4-phenyl-3-buten-4-olide with benzylamine was investigated as a model for polyamide synthesis. Linear polyamides were prepared from ringopening polyaddition of 4,4 -disubstituted bis(3-buten-4-olide) in m-cresol u g aliphatic diamines. Further studies have investigated the production of hydroxy-substituted polyamides from 4,4 -disubstituted bis(4-butanoiide) and polyamide production from 2,2 -p-phenylene bis-oxazolones by similar ring opening reactions with diamines. ... 

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