scholarly journals Compensation of Water Influence on Anionic Polymerization of ε-Caprolactam: 1. Chemistry and Experiments

2020 ◽  
Vol 4 (1) ◽  
pp. 7 ◽  
Author(s):  
Michael Wilhelm ◽  
Rainer Wendel ◽  
Martin Aust ◽  
Philipp Rosenberg ◽  
Frank Henning
Keyword(s):  
Ring Opening ◽  
Polyamide 6 ◽  
Polymer Properties ◽  
Highly Sensitive ◽  
Kinetic Tests ◽  
The Matrix ◽  
Influence Of Water ◽  
Significant Impairment ◽  
Added Water ◽  
Anionic Ring

The activated anionic ring opening polymerization of ε-caprolactam to polyamide 6 is highly sensitive to external influences such as water. Based on an initial theory, preliminary reaction kinetic tests are carried out with the aim of compensating the influence of the water by increasing the activator and catalyst concentration. Different formulations of activator and catalyst were studied to understand the influence of water on the concentration of activator and catalyst. It was found that the compensation of added water with activator and catalyst restores the original reaction time. The test plates produced are examined with regard to their mechanical characteristics and the polymer properties. The results of the mechanical characterization show no significant impairment after compensation of the added water. The physical properties of the matrix show degradation with repeated compensation. However, the residual ε-caprolactam content remains below the critical value of 1% for three of the four investigated formulations.

In situsynthesis of polyamide 6/MWNTs nanocomposites by anionic ring opening polymerization

2009 ◽  
Vol 111 (3) ◽  
pp. 1278-1285 ◽  
Author(s):  
Dongguang Yan ◽  
Tingxiu Xie ◽  
Guisheng Yang
Keyword(s):  
Ring Opening ◽  
Polyamide 6 ◽  
Ring Opening Polymerization ◽  
Anionic Ring

scholarly journals Magnetically Responsive PA6 Microparticles with Immobilized Laccase Show High Catalytic Efficiency in the Enzymatic Treatment of Catechol

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 239
Author(s):  
Nadya Dencheva ◽  
Sandra Oliveira ◽  
Joana Braz ◽  
Dariya Getya ◽  
Marc Malfois ◽  
...  
Keyword(s):  
Ring Opening ◽  
Catalytic Efficiency ◽  
Polyamide 6 ◽  
Relative Activity ◽  
Covalent Immobilization ◽  
Enzyme Adsorption ◽  
Citrate Buffer ◽  
Immobilized Laccase ◽  
Anionic Ring ◽  
Highly Porous

Herewith we report the first attempt towards non-covalent immobilization of Trametes versicolor laccase on neat and magnetically responsive highly porous polyamide 6 (PA6) microparticles and their application for catechol oxidation. Four polyamide supports, namely neat PA6 and such carrying Fe, phosphate-coated Fe and Fe3O4 cores were synthesized in suspension by activated anionic ring-opening polymerization (AAROP) of ε-caprolactam (ECL). Enzyme adsorption efficiency up to 92% was achieved in the immobilization process. All empty supports and PA6 laccase complexes were characterized by spectral and synchrotron WAXS/SAXS analyses. The activity of the immobilized laccase was evaluated using 2,2’-Azino-bis-(3- ethylbenzothiazoline-6-sulfonic acid (ABTS) and compared to the native enzyme. The PA6 laccase conjugates displayed up to 105% relative activity at room temperature, pH 4, 40 °C and 20 mM ionic strength (citrate buffer). The kinetic parameters of the ABTS oxidation were also determined. The reusability of the immobilized laccase-conjugates was proven for five consecutive oxidation cycles of catechol.

scholarly journals Enhanced Tensile Properties of Multi-Walled Carbon Nanotubes Filled Polyamide 6 Composites Based on Interface Modification and Reactive Extrusion

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 997
Author(s):  
Min Park ◽  
Ji-un Jang ◽  
Jong Hyuk Park ◽  
Jaesang Yu ◽  
Seong Yun Kim
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Properties ◽  
Ring Opening ◽  
Reactive Extrusion ◽  
Polyamide 6 ◽  
Ring Opening Polymerization ◽  
Uniform Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Anionic Ring ◽  
Walled Carbon Nanotubes

To induce uniform dispersion and excellent interfacial properties, we adopted a strategy of combining both polyamide 6 (PA6) grafting for multi-walled carbon nanotubes (MWCNTs) and reactive extrusion of PA6 matrix, based on anionic ring-opening polymerization of ε-caprolactam (CL). Compared to –COOH and –NCO treatments of MWCNTs, enhanced MWCNT dispersion and tensile properties of the composites were achieved using the applied strategy, and the tensile strength and modulus of the PA6-grafted MWCNT-filled PA6 composites were 5.3% and 20.5% higher than those of the purified MWCNT-filled PA6 composites, respectively. In addition, they were almost similar to the theoretical ones calculated by the modified Mori–Tanaka method (MTM) assuming a perfect interface, indicating that the tensile properties of MWCNT-filled PA6 composites can be optimized by PA6 grafting and reactive extrusion based on the anionic ring-opening polymerization of CL due to uniform MWCNT dispersion and excellent interfacial property.

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