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

2019 ◽  
Vol 166 ◽  
pp. 50-59 ◽  
Author(s):  
Jelena Vasiljević ◽  
Marija Čolović ◽  
Ivan Jerman ◽  
Barbara Simončič ◽  
Andrej Demšar ◽  
...  
Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 657 ◽  
Author(s):  
Jelena Vasiljević ◽  
Marija Čolović ◽  
Nataša Čelan Korošin ◽  
Matic Šobak ◽  
Žiga Štirn ◽  
...  

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.


2016 ◽  
Vol 87 (5) ◽  
pp. 561-569 ◽  
Author(s):  
Yuanyuan Li ◽  
Yunzhi Lin ◽  
Kai Sha ◽  
Ru Xiao

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.


Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1787
Author(s):  
Jelena Vasiljević ◽  
Andrej Demšar ◽  
Mirjam Leskovšek ◽  
Barbara Simončič ◽  
Nataša Čelan Korošin ◽  
...  

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.


2016 ◽  
Vol 16 (9) ◽  
pp. 9919-9924 ◽  
Author(s):  
Shanshan Wei ◽  
Leyu Wang ◽  
Ce Liu ◽  
Mulin Yu ◽  
Xianhong Chen ◽  
...  

2008 ◽  
Vol 19 (2) ◽  
pp. 241-244 ◽  
Author(s):  
Zhi Yong Wu ◽  
Wei Xu ◽  
Jin Kui Xia ◽  
Yao Chi Liu ◽  
Qian Xin Wu ◽  
...  

RSC Advances ◽  
2018 ◽  
Vol 8 (17) ◽  
pp. 9261-9271 ◽  
Author(s):  
Ke Liu ◽  
Yuanyuan Li ◽  
Lei Tao ◽  
Ru Xiao

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.


2012 ◽  
Vol 621 ◽  
pp. 44-47 ◽  
Author(s):  
Yun Zhi Lin ◽  
Kai Sha ◽  
Hai Yan Xu ◽  
Yin Tang ◽  
Ru Xiao

Melamine cyanurate (MCA) and bicyclic phosphates (BP) were combined and added into polyamide6 (PA6) with the polyethylene oxide (PEO) as dispersing agent by melt blend, then the flame retardant PA6 fibers were prepared by melt spinning. Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) were utilized to characterize the morphology and properties of the blends. The results indicated that the MCA particles with diametric size about 400nm are highly uniformly in the PA6 matrix, the spinnability and tensile strength of flame retardant PA6 fibers declined due to co-addition of MCA and M102B, TGA showed the flame retardant PA6 fibers decomposed early and retained high solid residue. From Flammability testing, an increase of oxygen index to 33.2% and an improvement of the UL-94 classification to V-0 were observed.


Author(s):  
S. Hagège ◽  
U. Dahmen ◽  
E. Johnson ◽  
A. Johansen ◽  
V.S. Tuboltsev

Small particles of a low-melting phase embedded in a solid matrix with a higher melting point offer the possibility of studying the mechanisms of melting and solidification directly by in-situ observation in a transmission electron microscope. Previous studies of Pb, Cd and other low-melting inclusions embedded in an Al matrix have shown well-defined orientation relationships, strongly faceted shapes, and an unusual size-dependent superheating before melting.[e.g. 1,2].In the present study we have examined the shapes and thermal behavior of eutectic Pb-Cd inclusions in Al. Pb and Cd form a simple eutectic system with each other, but both elements are insoluble in solid Al. Ternary alloys of Al (Pb,Cd) were prepared from high purity elements by melt spinning or by sequential ion implantation of the two alloying additions to achieve a total alloying addition of up to lat%. TEM observations were made using a heating stage in a 200kV electron microscope equipped with a video system for recording dynamic behavior.


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