Effect of Different Flame-Retardant Bridged DOPO Derivatives on Properties of in Situ Produced Fiber-Forming Polyamide 6

The production of sustainable and effective flame retardant (FR) polyamide 6 (PA6) fibrous materials requires the establishment of a novel approach for the production of polyamide 6/FR nanodispersed systems. This research work explores the influence of three different flame-retardant bridged 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivatives on the comprehensive properties of in situ produced PA6/FR systems. To this end, in situ water-catalyzed ring-opening polymerization of ε-caprolactam was conducted in the presence of three different bridged DOPO derivatives, e.g., one P−N bond phosphonamidate derivative and two P−C bond phosphinate derivatives. The selected bridged DOPO derivatives mainly act in the gas phase at the temperatures that relatively match the PA6 pyrolysis specifics. The effects of the FRs on the dispersion state, morphological, molecular, structural, melt-rheological, and thermal properties of the in situ synthesized PA6 were evaluated. The specific advantage of this approach is one-step production of PA6 with uniformly distributed nanodispersed FR, which was obtained in the case of all three applied FRs. However, the applied FRs differently interacted with monomer and polymer during the polymerization, which was reflected in the length of PA6 chains, crystalline structure, and melt-rheological properties. The applied FRs provided a comparable effect on the thermal stability of PA6 and stabilization of the PA6/FR systems above 450 °C in the oxygen-assisted pyrolysis. However, only with the specifically designed FR molecule were the comprehensive properties of the fiber-forming PA6 satisfied for the continuous conduction of the melt-spinning process.

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Characterization of Polyamide 6/Multilayer Graphene Nanoplatelet Composite Textile Filaments Obtained Via In Situ Polymerization and Melt Spinning

Polymers ◽

10.3390/polym12081787 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1787

Author(s):

Jelena Vasiljević ◽

Andrej Demšar ◽

Mirjam Leskovšek ◽

Barbara Simončič ◽

Nataša Čelan Korošin ◽

...

Keyword(s):

Melt Spinning ◽

In Situ Polymerization ◽

Complex Viscosity ◽

Polyamide 6 ◽

High Dispersion ◽

Multilayer Graphene ◽

Main Challenge ◽

Dispersion State ◽

Continuous Filament

Studies of the production of fiber-forming polyamide 6 (PA6)/graphene composite material and melt-spun textile fibers are scarce, but research to date reveals that achieving the high dispersion state of graphene is the main challenge to nanocomposite production. Considering the significant progress made in the industrial mass production of graphene nanoplatelets (GnPs), this study explored the feasibility of production of PA6/GnPs composite fibers using the commercially available few-layer GnPs. To this aim, the GnPs were pre-dispersed in molten ε-caprolactam at concentrations equal to 1 and 2 wt %, and incorporated into the PA6 matrix by the in situ water-catalyzed ring-opening polymerization of ε-caprolactam, which was followed by melt spinning. The results showed that the incorporated GnPs did not markedly influence the melting temperature of PA6 but affected the crystallization temperature, fiber bulk structure, crystallinity, and mechanical properties. Furthermore, GnPs increased the PA6 complex viscosity, which resulted in the need to adjust the parameters of melt spinning to enable continuous filament production. Although the incorporation of GnPs did not provide a reinforcing effect of PA6 fibers and reduced fiber tensile properties, the thermal stability of the PA6 fiber increased. The increased melt viscosity and graphene anti-dripping properties postponed melt dripping in the vertical flame spread test, which consequently prolonged burning within the samples.

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In situ prepared polyamide 6/DOPO-derivative nanocomposite for melt-spinning of flame retardant textile filaments

Polymer Degradation and Stability ◽

10.1016/j.polymdegradstab.2019.05.011 ◽

2019 ◽

Vol 166 ◽

pp. 50-59 ◽

Cited By ~ 14

Author(s):

Jelena Vasiljević ◽

Marija Čolović ◽

Ivan Jerman ◽

Barbara Simončič ◽

Andrej Demšar ◽

...

Keyword(s):

Flame Retardant ◽

Melt Spinning ◽

Polyamide 6

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Preparation and characterizations of flame retardant melamine cyanurate/polyamide 6 composite fibers via in situ polymerization

Textile Research Journal ◽

10.1177/0040517516632478 ◽

2016 ◽

Vol 87 (5) ◽

pp. 561-569 ◽

Cited By ~ 20

Author(s):

Yuanyuan Li ◽

Yunzhi Lin ◽

Kai Sha ◽

Ru Xiao

Keyword(s):

Flame Retardant ◽

Flame Retardancy ◽

Melt Spinning ◽

Cyanuric Acid ◽

In Situ Polymerization ◽

Polyamide 6 ◽

Composite Fibers ◽

Limiting Oxygen Index ◽

Melamine Cyanurate

To improve the flame retardancy of polyamide 6 (PA6) fibers, melamine cyanurate (MCA)/PA6 composites were synthesized via in situ polymerization of ɛ-caprolactam in the presence of adipic acid-melamine salt and cyanuric acid-hexane diamine salt. The flame retardant MCA/PA6 composite fibers were prepared by melt spinning. The structure and properties of MCA/PA6 composites and MCA/PA6 composite fibers were studied by Fourier transform infrared spectra, X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, tensile tests, vertical burning tests (UL94) and limiting oxygen index (LOI) tests. Experimental results indicated that the MCA/PA6 composites loaded with 8 wt% of additives can achieve UL94 V-0 rating with an LOI value of 29.3%. The tenacity at break of PA6 fiber decreased from 4.85 to 3.11 cN·dtex–1 for MCA/PA6-8 composite fiber. However, the MCA/PA6 composite fibers can effectively suppress the propagation of flame in fabric. This means that the in situ polymerization approach paves the way for the preparation of MCA/PA6 composites that have good spinnability and flame retardancy.

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A novel approach of in situ grafting polyamide 6 to the surface of multi-walled carbon nanotubes

Materials Letters ◽

10.1016/j.matlet.2008.10.013 ◽

2009 ◽

Vol 63 (2) ◽

pp. 298-300 ◽

Cited By ~ 26

Author(s):

Dongguang Yan ◽

Guisheng Yang

Keyword(s):

Carbon Nanotubes ◽

Polyamide 6 ◽

Novel Approach ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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In-Situ X-Ray Characterization of Fiber Structure during Melt Spinning

Journal of Engineered Fibers and Fabrics ◽

10.1177/155892500800300302 ◽

2008 ◽

Vol 3 (3) ◽

pp. 155892500800300 ◽

Cited By ~ 6

Author(s):

Michael S. Ellison ◽

Paulo E. Lopes ◽

William T. Pennington

Keyword(s):

Melt Spinning ◽

Simultaneous Detection ◽

Polymer Melt ◽

Polymer Chains ◽

Degree Of Crystallinity ◽

Structure Evolution ◽

X Ray ◽

Spinning Process

The properties of a polymer are strongly influenced by its morphology. In the case of fibers from semi-crystalline polymers this consists of the degree of crystallinity, the spacing and alignment of the crystalline regions, and molecular orientation of the polymer chains in the amorphous regions. Information on crystallinity and orientation can be obtained from X-ray analysis. In-situ X-ray characterization of a polymer during the melt spinning process is a major source of information about the effects of material characteristics and processing conditions upon structure evolution along the spinline, and the final structure and properties of the end product. We have recently designed and installed an X-ray system capable of in-situ analysis during polymer melt spinning. To the best of our knowledge this system is unique in its capabilities for the simultaneous detection of wide angle and small angle X-ray scattering (WAXS and SAXS, respectively), its use of a conventional laboratory radiation source, its vertical mobility along the spinline, and its ability to simulate a semi-industrial environment. Setup, operation and demonstration of the capabilities of this system is presented herein as applied to the characterization of the melt spinning of isotactic poly(propylene). Crystallinity and crystalline orientation calculated from WAXS patterns, and lamellar long period calculated from SAXS patterns, were obtained during melt spinning of the polymer along the spinline.

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Study of the Proper Sintering Conditions of Anionically-Polymerized Polyamide 6 Matrices for the Fabrication of Greencomposites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.713.121 ◽

2012 ◽

Vol 713 ◽

pp. 121-126

Author(s):

A. Alfonso ◽

J. Andrés ◽

J.A. García

Keyword(s):

Material Characterization ◽

Mechanical Performance ◽

In Situ Polymerization ◽

Research Work ◽

Polyamide 6 ◽

Liquid Composite Molding ◽

Thermoplastic Matrix ◽

Composite Molding ◽

Long Fiber Thermoplastic

The present research work assesses the manufacture of long fiber thermoplastic matrix composite materials (GreenComposites). Thermoplastic matrices are too viscous to be injected into the conventional LCM (Liquid Composite Molding) molds, and then epoxy, polyester or vinylester resins are used. Nevertheless, the groundbreaking anionic polymerization of caprolactam allows such a synthesis of a thermoplastic APA6 matrix inside the mold. This matrix is sintered from the starting monomers, and presents high mechanical performance and recyclability. In order to do the reactive injection in a LCM mold, it is necessary to control the polymerization mechanism of such a thermoplastic matrix. This paper puts special emphasis on detecting and solving all problems which arose during synthesis. For instance, moisture values were assessed for all starting reactants, since humidity keeps polymerization from occurring. It is thought that once the synthesis and the resulting material characterization are well controlled, the manufacture of GreenComposites through in situ polymerization, as well as addition of state-of-the-art fabrics such as basalt, can proceed successfully.

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Preparation of Polyamide 6/Silica Modified Melamine Cyanurate Non-Halogen Flame Retardant Nanocomposites by In Situ Polymerization

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2016.10613 ◽

2016 ◽

Vol 16 (9) ◽

pp. 9919-9924 ◽

Cited By ~ 1

Author(s):

Shanshan Wei ◽

Leyu Wang ◽

Ce Liu ◽

Mulin Yu ◽

Xianhong Chen ◽

...

Keyword(s):

Flame Retardant ◽

Polyamide 6 ◽

Melamine Cyanurate

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High-Performance Biobased Unsaturated Polyester Nanocomposites with Very Low Loadings of Graphene

Polymers ◽

10.3390/polym10111288 ◽

2018 ◽

Vol 10 (11) ◽

pp. 1288 ◽

Cited By ~ 3

Author(s):

Chengguo Liu ◽

Cuina Wang ◽

Jijun Tang ◽

Jing Zhang ◽

Qianqian Shang ◽

...

Keyword(s):

High Performance ◽

Graphene Nanosheets ◽

Unsaturated Polyester ◽

Diels Alder ◽

Mechanical And Thermal Properties ◽

Comprehensive Properties ◽

Melt Polycondensation ◽

Dispersion State ◽

Structural Plastics

Graphene-reinforced tung oil (TO)-based unsaturated polyester nanocomposites were prepared via in situ melt polycondensation intergrated with Diels–Alder addition. Functionalized graphene sheets derived from graphene oxide (GO) were then extracted from the obtained nanocomposites and carefully characterized. Furthermore, dispersion state of the graphene nanosheets in the cured polymer composites and ultimate properties of the resultant biobased nanocomposites were investigated. Mechanical and thermal properties of the TO-based unsaturated polyester resin (UPR) were greatly improved by the incorporation of GO. For example, at the optimal GO content (only 0.10 wt %), the obtained biobased nanocomposite showed tensile strength and modulus of 43.2 MPa and 2.62 GPa, and Tg of 105.2 °C, which were 159%, 191%, and 49.4% higher than those of the unreinforced UPR/TO resin, respectively. Compared to neat UPR, the biobased UPR nanocomposite with 0.1 wt % of GO even demonstrated superior comprehensive properties (comparable stiffness and Tg, while better toughness and thermal stability). Therefore, the developed biobased UPR nanocomposites are very promising to be applied in structural plastics.

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Flame retardant polyamide 6 by in situ polymerization of ɛ-caprolactam in the presence of melamine derivatives

Chinese Chemical Letters ◽

10.1016/j.cclet.2007.12.012 ◽

2008 ◽

Vol 19 (2) ◽

pp. 241-244 ◽

Cited By ~ 16

Author(s):

Zhi Yong Wu ◽

Wei Xu ◽

Jin Kui Xia ◽

Yao Chi Liu ◽

Qian Xin Wu ◽

...

Keyword(s):

Flame Retardant ◽

In Situ Polymerization ◽

Polyamide 6

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Preparation and characterization of polyamide 6 fibre based on a phosphorus-containing flame retardant

RSC Advances ◽

10.1039/c7ra13228j ◽

2018 ◽

Vol 8 (17) ◽

pp. 9261-9271 ◽

Cited By ~ 19

Author(s):

Ke Liu ◽

Yuanyuan Li ◽

Lei Tao ◽

Ru Xiao

Keyword(s):

Flame Retardant ◽

Melt Spinning ◽

Polyamide 6 ◽

Melt Polycondensation ◽

Phosphorus Containing

Intrinsically flame retardant polyamide 6 (FRPA6) was synthesized by melt polycondensation of caprolactam and 9,10-dihydro-10-[2,3-di(hydroxycarbonyl)propyl]-10-phosphaphenanthrene-10-oxide (DDP). And the FRPA6 fibres were prepared by melt spinning.

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