Polyamide cycloaliphatic

Until the early 1960s the aromatic and cycloaliphatic polyamides were largely laboratory curiosities. By 1980 they were still only of minor importance to the plastics industry but of rapidly expanding interest as fibre-forming materials with a particular potential as tyre cord materials. 

Telechelic polymers rank among the oldest designed precursors. The position of reactive groups at the ends of a sequence of repeating units makes it possible to incorporate various chemical structures into the network (polyether, polyester, polyamide, aliphatic, cycloaliphatic or aromatic hydrocarbon, etc.). The cross-linking density can be controlled by the length of precursor chain and functionality of the crosslinker, by molar ratio of functional groups, or by addition of a monofunctional component. Formation of elastically inactive loops is usually weak. Typical polyurethane systems composed of a macromolecular triol and a diisocyanate are statistically simple and when different theories listed above are... 

The best performing coatings studied were a vinyl ester, a bisphe-nol A epoxy cured with an aliphatic amine, and a novolac epoxy cured with a mixed aromatic/cycloaliphatic amine. A saturated polyester, and a bisphenol A epoxy cured with a polyamide amine showed significant deterioration in the acid and corrosion of the underlying steel. Two types of novolac epoxies cured with aromatic amines showed intermediate performance. 

Curing agents account for much of the potential hazard associated with use of epoxy resins. There are several major types of curing agents aliphatic amines, aromatic amines, cycloaliphatic amines, acid anhydrides, polyamides, and catalytic curing agents. The latter two types are true catalysts, in that they do not participate in the curing process. 

Suitable curatives for the polysulfide-epoxy reaction include liquid aliphatic amines, liquid aliphatic amine adducts, solid amine adducts, liquid cycloaliphatic amines, liquid amide-amines, liquid aromatic amines, polyamides, and tertiary amines. Primary and secondary amines are preferred for thermal stability and low-temperature performance. Not all amines are completely compatible with polysulfide resins. The incompatible amines may require a three-part adhesive system. The liquid polysulfides are generally added to the liquid epoxy resin component because of possible compatibility problems. Optimum elevated-temperature performance is obtained with either an elevated-temperature cure or a postcure. 

The branched diamines discussed previously have nine carbon atoms. Entirely different diamine structures can be built up from nine carbon atoms. Three products (diamines) with characteristically different carbon skeletons were available an unbranched linear product (nonamethyl-enediamine), a branched product, (trimethylhexamethylenediamine), and a cycloaliphatic compound (IPD) with 10 carbon atoms. Polyamides... 

Recall that conventional polyamides (e.g. nylon) contain mostly aliphatic and cycloaliphatic units in the macromolecular chain structure. These can be melt... 

Note 1 = polyamide, Ancamide 350A 2 = amidoamine, Ancamide 506 3 = cycloaliphatic-A, Ancamine 1618 4 = cycloaliphatic-MB, Ancamine MCA 5 = aromatic, Ancamine TL/TLS 6 = aliphatic-A, Ancamine 1608 7 = aliphatic-MB, Ancamine 1856 A = adduct-type MB = Mannich-base-type. 

A number of polyamide copolymers are known to have practical uses. The copolymers include those with different amides such as poly(caprolactam-co-laurolactam), poly(2,2,4-trimethyl-1,6-hexandiamine-co-2,4,4-trimethyl-1,6-hexandiamnie-co-1,4-benzendicarboxylic acid), poly(s-caprolactam-co-hexamethylene diamine-co-terephthalic acid), poly(hexamethylenediamine-co-terephthalic acid-co-isophthalic acid), etc. The addition of longer alkyl chains in an aromatic polymeric amide may improve some mechanical properties, but thermal resilience is in general reduced. For example, poly(hexamethylenediamine-co-m-xylylenediamine-co-isophthalic acid-co-terephthalic acid) starts decomposing at about 310° C, significantly lower than Nomex , for example. The same decrease in the decomposition temperature is seen for other mixed copolymers such as nylon 12 copolymers that include cycloaliphatic and aromatic segments. 

Another example of cycloaliphatic group incorporation in Table III is the data for PACM/6-I/T (made from the nylon salt) (Vassallo, D. A., DuPont, unpublished results). In this case, hydrogen bonding is possible, but the distance between amide nitrogens has increased. It is difficult from these examples to delineate the effect of the aliphatic rings on polyamide OPV, although it is likely that their presence increases interchain distance much as a chain substituent would. 

Cycloaliphatic diamines which have reacted with diacids to form polyamides generate performance polymers whose physical properties are dependent on the diamine geometric isomers. (58,74). Proprietary transparent thermoplastic polyadipamides have been optimized by selecting the proper mixtures of PDCHA geometric isomers (32—34) for incorporation (75) ... 

Yu, S., Liu, M., Lii, Z., Zhou, Y., and Gao, C. 2009. Aromatic-cycloaliphatic polyamide thin-film composite membrane with improved chlorine resistance prepared from m-phenylenediamineA-methyl and cyclohexane-1,3,5-tricar-bonyl chloride. Journal of Membrane Science 344 155-164. 

Chem. Descrip. Modified cycloaliphatic amine epoxy Uses Epoxy curing agent for high solids coatings accelerator for polyamide and amidoamine curing agents Features Good chem. resist, and low temp, cure (30-35 E) exc. blush resist. 

One commercial polyamide is prepared by condensation of a cycloaliphatic diamine with a twelve-carbon dicarboxylic acid. The diamine, bis(p-aminocyclohexyl)methane, is prepared from aniline ... 

Nylon-5 n. A blend of aliphatic-, cycloaliphatic-, and aromatic-based polyamides. The material is clear in thick cross-sections, has low water absorption, good dimensional stability and solvent resistance, and can be processed economically in injection molding or extrusion. 

Another glass-clear polyamide was announced in the mid-1970s by Hoechst a polynorbomamide, it was marketed as Hostamid. The basic patent suggests that this material is a copolyamide of a mixture of isomeric bisamino-methylnorbomanes (Figure 18.26 (I) and (II)) with aliphatic or cycloaliphatic dicarboxylic acids with 2-20 carbon atoms or aromatic dicarboxylic acids with 7-20 carbon atoms as well as diamines, amino acids of lactams. The properties of this polymer are similar in many respects to those of Trogamid T, with a of... 

Polyamides/amidoamines Aromatic amines Cycloaliphatic amines Polyisocyanates... 

Several types of hardeners are used in the curing Aliphatic amines Amidoamines Aromatic amines Cycloaliphatic amines Imidazoles Polyamides Anhydrides Polysulfides Mercaptans Dicyandiamide (DiCy)... 

The most commonly used curing agents for ambient cured adhesives are polyamides, aliphatic amines, cycloaliphatic amines and ami-doamines. The choice of hardener is dependent on the performance requirements of the adhesive. For high performance, high temperature... 

Figure 6 Chemical formulae of the catalysts and co-reactants used as curing agents of epoxy resins electrophilic 33 and nucleophilic 34-36 catalysts, dicyandiamide 37, ureas 38, 39, imidazoles 40-47, aliphatic amines 48, 49, polyamide 50, and cycloaliphatic...

Examples of catalysts are shown on the first line, whereas all the other compounds are coreactants including dicyandiamide, ureas, imidazoles, aliphatic polyamines, cycloaliphatic polyamides, and cycloaliphatic dicarboxylic acid anhydrides. As all the corresponding reaction mechanisms have been previously disclosed in detail," the following presentation is limited to the initial reaction steps leading to the active species involved in the polymerization or polycondensation processes. These primary attacks are enlightened in Fig. 12.6, which displays only one epoxy group reacting with catalysts or coreactants. 

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