Methyl-substituted polyamides

Aliphatic hyperbranched polyesters, 56 Aliphatic isocyanate adducts, 202 Aliphatic isocyanates, 210, 225 Aliphatic polyamides, 138 Aliphatic polyesteramides, 56 Aliphatic polyesters, 18, 20, 29, 32, 87 degradable, 85 hyperbranched, 114-116 melting points of, 33, 36 structure and properties of, 40-44 syntheses of, 95-101 thermal degradation of, 38 unsubstituted and methyl-substituted, 36-38... 

The results obtained here confirm their findings, and extend them by showing that even a small percent of N-methylation is sufficient to change the hydrodynamic properties of the para-linked aromatic polyamide molecule. The agreement between the molecular weights measured for polymer 7 (50% N-methyl substitutive) in 96% sulfuric acid and the N-methyl pyrrolidone with 5% LiCl and 1% water implies that this polymer forms a molecularly disperse solution in the latter solvent. This observation differs significantly from the report by Tsvetkov et al. (6) and Koton and Nozova (5) that the fully methylated polymer only formed molecularly disperse solutions in sulfuric acid. 

Table II. Degradation of Methyl- and Hydroxy-Substituted Polyamides by Fungi and Enzymes...

T. D. Greenwood, R. A. Kahley, and J. E Wolfe, 7/-methyl-substituted aromatic polyamides, Journal of Polymer Science Polymer Chemistry Edition, 18, 1047(1980). 

Structure-Property Studies.— NyIon-2 polymers and copolymers, poly-(2,5-dimethylterephthalamides), wholly aromatic polyamides containing methyl-substituted phenylene linkages, and copolyamides based on caprolactam and hexamethyleneadipamide have been studied and properties related to structure. 

If the superimposed sextet is subtracted from the original spectrum a triplet remains which must be due to a scission product of the above molecule. The exclusive breakage of bonds 3 and 4 can be ruled out immediately since it would only lead to radicals of type III. Breakage of bonds 6 and 7 was eliminated after comparison with capron deuterated in the imino groups breakage of bond 1 would not lead to a radical with a triplet spectrum. After inspection of all other possibilities, including secondary radicals, there remain as likely scission points only the bonds 2 and 5. After having studied a and e methyl substituted caprolactam the authors [10] finally were able to state that in a stressed 6 polyamide molecule both the bonds 2 and 5 do break and with equal probability. The rupture of a PA 6 molecule, therefore, leads to three primary radicals ... 

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. 

It should be noted that functionalised diacetylene monomers have also been used for coupling reactions with haloarenes. By reacting diacetylene-substituted p-aminoanilines [135] and diethynyl(methyl)( -octyl)silane [136] with diiodoarenes, polyamides and polysilanes have been prepared, respectively. 

Table IX lists an additional substance, described by Saotome and Komoto (10). This polyamide is identical to one of the Temin polyamides, except for the substitution of the hydrogen at the NH group by a methyl group. Hence, this polyamide cannot form hydrogen bridges. Unfortunately, the glass temperature was not determined—only the softening point. Shashoua (12) described a similar product, a poly-...

Figure 1.15 shows polyisobutylene, a vinylidene polymer with symmetric substitution, and thus without stereoisomers. Cis and trans isomers are possible in butenylene polymers. Two examples are at the bottom of Fig. 1.15. They are not interconvertable by rotating of the molecule. Shown in the figures are the trans isomers (). In the cis isomers the backbone chain continues on the same side of the double bond ( /). In Figs. 1.16 and 1.17 a series of vinyl and vinylidene polymers are shown. The above-mentioned PTFE, poly(vinyl butyral), and poly (methyl methacrylate) are given, starting in Fig. 1.17. Polyoxides are drawn at the bottom of Fig. 1.17, and the top of Fig. 1.18. Poly(ethylene terephthalate) and two aliphatic polyamides (nylon 6,6 and nylon 6) round out Fig. 1.18. The 20 polymers just looked at should serve as an initial list that must be extended many-fold during the course of study of thermal analysis of polymeric materials.

Thermal stability measurements have been carried out on numerous other polymers including polyethylene ethylene vinyl-alcohol copolymer [12], polyaniline [13], ) 3 s-stilbene-N-substituted maleimides [14], cellulose [15-20], polystyrene [14, 16], ethylene-styrene copolymers [21,22], ST-DVB-based ion exchangers [23], vinyl chloride-acrylonitrile copolymers [24], polyethylene terephthalate [25], polyesters such as polyisopropylene carboxylate [26], polyglycollate [27-29], Nylon 6 [30], polypyromellitimides, poly-N-a-naphthylmaleimides [26,31], polybenzo-bis(amino-imino pyrolenes) [32], polyvinyl chloride [33-35], acrylamide-acrylate copolymers and polyacrylic anhydride [36-38], polyamides [39], amine-based polybenzo-oxazines [40], polyester hydrazides [41], poly-a-methyl styrene tricarbonyl chromimn [42], polytetrahydrofuran [43], polyhexylisocyanate [44], polyurethanes [45], ethylene-... 

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... 

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