Pyrrolidone, Capryllactam and Laurolactam as new Monomers for Polyamide Fibers

Abstract

carriers promcite disperse dyeability of the nytril fiber at 100 "C is not completely understood but may involve an increase in both affinity and diffusion rate. Typical carriers such as methyl p-toluate and o-phenylphenol combine strongly with many disperse dyes and, when inside the fiber, may act as temporary dye sites. In addition, these compounds are strong solvating agents for sites of dipole interaction and thus may be expected to lower the wet glass transition temperature to some degree, resulting in improved diffusion rate.While a discussion of the properties and performance of fabrics made from Darvan@ nytril fiber is beyond the scope of this paper, it should be stated that the postulates concerning performance which have been derived from fiber properties have been borne out by extensive fabric trials. Soft texture, resilience, shape retention throughout wearing and laundering, and a high degree of resistance to wrinkling have been experienced with such fabrics. Relationship of Properties to Fiber StructureThe outstanding features of softness, elasticity, resilience, and resistance to moisture displayed by the nytril fiber may be traced directly to its chemical constitution and fine structure. The relatively low degree of orientation and lateral order, together with the large number of points of intermolecular attraction provided by the polarized cyano groups, result in a strong, flexible network of molecules. This, in turn, is responsible for the soft, resilient texture of the fiber. The strength of the dipole-pair intermolecular bond, which is of the order of 8-10 kcal./mol. for alkyl cyanides [7] and which is probably much higher for vinylidene cyanide, owing to resonance, together with the large number of such bonds, probably accounts for the high degree of elastic recovery, the good wrinkle resistance, and the relative insensitivity to hot water. These same factors, of course, would tend to increase the wet glass transition temperature and reduce the dye diffusion rate. The industrial production of capryllactam (I-azacyclononan-2-one) and of laurolactam (I-azacyclotridecan-2-one) starts with cyclization of acetylene or butadiene to give cyclooctatetraene or cyclooctadiene, or cyclization of butadiene to give cyclododecatriene. Further steps are: oxidation of the cyclic hydrocarbon to the ketone, formation of the oxime, and rearrangement of the latter with sulfuric acid. Pyrrolidone can be prepared from acetylene and formaldehyde by way of butyrolactone. The behavior of the lactams during polycondensation is described and the properties of the resulting fibers are compared with those of the known polyamide fibers. It is impossible to give individual credit for specific aspects

Structure–Property Relationships of Poly(glycolic acid) and Poly(2-hydroxybutyrate)

“…The PMO chain has no well-defined interchain attraction but nevertheless shows a small S conf value, ,− which leads to a small Δ S u and, consequently, a high T m 0 of 206 °C . The α form of nylons 4 and 6 includes all-trans chains that are bridged by the classical CO···H–N hydrogen bond, , which causes comparatively large negative Δ E CP ’s and Δ H u ’s and, furthermore, high T m 0 ’s. ,, Of the polymers in Table , PGA exhibits the largest negative Δ E CP (in cal g –1 ) although it forms no classical hydrogen bond. The all-trans crystallization is probably due mainly to the electrostatic and dipole–dipole attractions and partly to the weak C–H···O hydrogen bond, − , and these attractions are more effective in the all-trans structure than in the tgt conformation.…”

Computational Characterization of Nylon 4, a Biobased and Biodegradable Polyamide Superior to Nylon 6

“…The scaled values suggest that nylon 4 would be more thermally stable than nylon 6. Actually, the melting point of nylon 4 has been observed in the range of 260–265 °C, 13 whereas the equilibrium melting point ( T m 0 ) of nylon 6 was determined to be 225 °C. 14 However, it should be noted that the Δ E CP (∞) value at 0 K derived here is a measure of thermal stability, because, strictly, T m 0 = Δ H u /Δ S u , where Δ H u and Δ S u are the enthalpy and entropy of fusion, respectively.…”

Uniaxial tensile viscoelastic and viscoplastic behaviour of Nylon 12 at constant strain rate

“…1-8 Nylon 12 will exhibit both glassy and rubbery behaviour in the temperature range studied. The experimental procedure discussed was conducted initially at temperatures of between 25 and 35uC and an attempt was made to fit the experimental data to equations (9) and (10) and evaluate temperature dependence for the adjustable parameters E and f in this narrow temperature range. The change in adjustable parameters can be described based on the viscoelastic response of the material, in that for semicrystalline polymers the amorphous phase is located between spherulites, inside spherulites as 'liquid pockets' between lamellar stacks and between lamellae in lamellar stacks.…”

“…2% moisture at saturation. [9][10][11] Nylon 12 is a semicrystalline material with spherulites of various types distributed within an amorphous matrix, the main stable crystal type of Nylon 12 being the c-modification with a pseudo hexagonal unit cell with a5b50 . 478 nm and c (chain direction)53 .…”