Copolymerization Of E-caprolactam Research Articles

Simultaneous Anionic Ring-Opening and Condensation Reactions for the Synthesis of Aliphatic–N-Alkyl Aromatic Copolyamides

The copolymerization of e-caprolactam with ethyl 4-(butylamino)benzoate was shown to occur in the presence of sodium salts and an acyllactam as activator in a one-step bulk reaction. The mechanism is based on the deprotonation of the two monomers yielding activated species able to attack an acyllactam or an ester group at the polymer chain ends. Novel copolyamides with different percentages of aromatic/aliphatic units were synthesized in a one-step bulk copolymerization within a few minutes at 140 °C and characterized by NMR spectroscopy, size exclusion chromatography, and thermal analysis (DSC). This methodology, combining simultaneous anionic ring-opening and condensation reactions, affords a new synthetic pathway to introduce an aromatic unit in an aliphatic polyamide backbone, and more specifically a polyamide 6 containing about 20 mol % of N-alkyl aromatic amides was prepared.

Effects of different composition ratio on the dielectric relaxation and dynamic mechanical properties of poly(ω-dodecalactam-co -ε-caprolactam-co -propylene oxide) copolymers

The molecular dynamics of new poly (x-dodecalac- tam-co-e-caprolactam-co-propylene oxide) copolymers (DL/CL/ PAC) has been investigated by using dynamic mechanical ther- mal analysis (DMTA) and dielectric relaxation spectroscopy (DRS) measurements. The copolymers were synthesized via anionic poly- merization of relevant lactams activated with carbamoyl deriva- tives of telechelic hydroxyl terminated polypropylene oxide with isophorone diisocyanate (PAC). The calorimetric, X-ray diffrac- tion, and DMTA measurements were performed to recognize the influence of the composition ratio and the type of PAC on the physical, thermal, and mechanical properties of the synthesized copolymers. The DRS was used to study the frequency depend- ence of the dielectric permittivity of some isotherms from � 110 to 145 � C. Copolymerization of e-caprolactam with about 10 wt % x-dodecalactam results in a copolymer that has lower water absorption, a melting point close to that of polyamide 6 and has a high enough degree of crystallinity in respect to high storage modulus. Five dielectric relaxations have been observed in the dielectric spectra, three at lower temperature and two at higher temperature. The copolymers have two glass transition tempera- tures for polyamide segments and polyether blocks, indicating microphase separation in the copolymers. Other studies directed toward molecular dynamics of polyamide DL/CL/PAC copolymers have not been reported. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 2518-2529, 2010

Electrical DC conduction mechanism in some newly synthesized nylon 6/12 copolymers

AbstractThe synthesis and the study of DC electrical transport properties (electrical conductivity, σ, and Seebeck coefficient,S) as a function of temperature of some recently synthesized nylon 6/12 copolymers with 0, 5, 10, 20, 30, and 50 wt % laurolactam (LL), respectively, are reported. Nylons were obtained by rotational molding via the anionic activated copolymerization of ε‐caprolactam and LL. As evidenced by XRD analyses, they are semicrystalline. The temperature dependences of σ andSare typical for polycrystalline semiconducting (p‐type) materials. The activation energy of electrical conduction lay in the range 0.79–1.22 eV, while the ratio of charge carrier mobilities ranged between 0.53 and 0.77. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 794–799, 2007

Anionic polymerization of ε-caprolactam and its copolymerization with ω-dodecanelactam in the presence of aromatic polyimides

The anionic polymerization of e-caprolactam in the presence of aromatic polyimides as activators has been studied under adiabatic conditions. It has been shown that despite the crosslinked structure the produced graft copolymers of polycaproamide and polyimides contain the crystalline phase and are characterized by better water resistance and thermal stability, a higher content of the gel fraction, and improved mechanical properties as compared to copolymers prepared under the so-called isothermal conditions. It has been demonstrated that the catalytic system MgBr-e-caprolactam-aromatic polyimide may be used for the anionic copolymerization of e-caprolactam with ω-dodecanelactam, and experimental conditions providing a copolymer yield of 75% have been developed.