scholarly journals Melt-Spinning of an Intrinsically Flame-Retardant Polyacrylonitrile Copolymer

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4826
Author(s):  
Simon König ◽  
Philipp Kreis ◽  
Christian Herbert ◽  
Andreas Wego ◽  
Mark Steinmann ◽  
...  

Poly(acrylonitrile) (PAN) fibers have two essential drawbacks: they are usually processed by solution-spinning, which is inferior to melt spinning in terms of productivity and costs, and they are flammable in air. Here, we report on the synthesis and melt-spinning of an intrinsically flame-retardant PAN-copolymer with phosphorus-containing dimethylphosphonomethyl acrylate (DPA) as primary comonomer. Furthermore, the copolymerization parameters of the aqueous suspension polymerization of acrylonitrile (AN) and DPA were determined applying both the Fineman and Ross and Kelen and Tüdõs methods. For flame retardancy and melt-spinning tests, multiple PAN copolymers with different amounts of DPA and, in some cases, methyl acrylate (MA) have been synthesized. One of the synthesized PAN-copolymers has been melt-spun with propylene carbonate (PC) as plasticizer; the resulting PAN-fibers had a tenacity of 195 ± 40 MPa and a Young’s modulus of 5.2 ± 0.7 GPa. The flame-retardant properties have been determined by Limiting Oxygen Index (LOI) flame tests. The LOI value of the melt-spinnable PAN was 25.1; it therefore meets the flame retardancy criteria for many applications. In short, the reported method shows that the disadvantage of high comonomer content necessary for flame retardation can be turned into an advantage by enabling melt spinning.

2015 ◽  
Vol 17 (1) ◽  
pp. 123-133 ◽  
Author(s):  
S. Basak ◽  
Kartick. K. Samanta ◽  
S. Saxena ◽  
S.K. Chattopadhyay ◽  
R. Narkar ◽  
...  

Abstract Flame retardancy was imparted in cellulosic cotton textile using banana pseudostem sap (BPS), an eco-friendly natural product. The extracted sap was made alkaline and applied in pre-mordanted bleached and mercerized cotton fabrics. Flame retardant properties of both the control and the treated fabrics were analysed in terms of limiting oxygen index (LOI), horizontal and vertical flammability. Fabrics treated with the non-diluted BPS were found to have good flame retardant property with LOI of 30 compared to the control fabric with LOI of 18, i.e., an increase of 1.6 times. In the vertical flammability test, the BPS treated fabric showed flame for a few seconds and then, got extinguished. In the horizontal flammability test, the treated fabric showed no flame, but was burning only with an afterglow with a propagation rate of 7.5 mm/min, which was almost 10 times lower than that noted with the control fabric. The thermal degradation and the pyrolysis of the fabric samples were studied using a thermogravimetric analysis (TGA), and the chemical composition by FTIR, SEM and EDX, besides the pure BPS being characterized by EDX and mass spectroscopy. The fabric after the treatment was found to produce stable natural khaki colour, and there was no significant degradation in mechanical strengths. Based on the results, the mechanism of imparting flame retardancy to cellulosic textile and the formation of natural colour on it using the proposed BPS treatment have been postulated.


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.


2015 ◽  
Vol 1115 ◽  
pp. 406-409 ◽  
Author(s):  
Fatimah A’thiyah Sabaruddin ◽  
Noorasikin Samat ◽  
A.I.H Dayang Habibah

It is known that polymeric materials are easily to get on fire due to their chemical structures. Thus the flame retardant material such as aluminium hydroxide (ATH) is used to improve the flame retardancy property of polymers. Polypropylene (PP) with various amount of nanosized ATH particles of (5, 10, 20, 30, 40 wt%) were compounded with an extruder machine. The effects of two different type of coupling agent (3-Aminopropyltriethoxysilane (APS) and Maleic anhydride grafted polypropylene (MAPP)) on the flame retardant properties were compared. All samples were characterized with two flame tests; the limiting oxygen index (LOI) and UL94 horizontal burning test (UL94 HB). It is found that both tests showed improvement on the flame resistance properties of the nanocomposites, mainly at high ATH loadings. Type of coupling agents affects the flame retardancy properties of PP/ATH nanocomposites.


Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3656
Author(s):  
Hangfeng Yang ◽  
Hangbo Yue ◽  
Xi Zhao ◽  
Minzimo Song ◽  
Jianwei Guo ◽  
...  

A novel halogen-free flame retardant containing sulfonamide, 1,3,5,7-tetrakis (phenyl-4-sulfonamide) adamantane (FRSN) was synthesized and used for improving the flame retardancy of largely used polycarbonate (PC). The flame-retardant properties of the composites with incorporation of varied amounts of FRSN were analyzed by techniques including limited oxygen index, UL 94 vertical burning, and cone calorimeter tests. The new FR system with sulfur and nitrogen elements showed effective improvements in PC’s flame retardancy: the LOI value of the modified PC increased significantly, smoke emission suppressed, and UL 94 V-0 achieved. Typically, the composite with only 0.08 wt% of FRSN added (an ultralow content) can increase the limiting oxygen index (LOI) value to 33.7% and classified as UL 94 V-0 rating. Furthermore, the mechanical properties and SEM morphology indicated that the FRSN has very good compatibility with PC matrix, which, in turn, is beneficial to the property enhancement. Finally, the analysis of sample residues after burning tests showed that a high portion of char was formed, contributing to the PC burning protection. This synthesized flame retardant provides a new way of improving PC’s flame retardancy and its mechanical property.


2011 ◽  
Vol 175-176 ◽  
pp. 465-468 ◽  
Author(s):  
Lei Shi ◽  
Hua Wu Liu ◽  
Ping Xu ◽  
Dang Feng Zhao

Plain weave fabrics of polyacrylonitrile pre-oxidation yarns (PANOF) were prepared by small rapier loom. The flame retardation properties, mechanical properties and wear behaviors of PANOF plain weave fabrics were tested. The limiting oxygen index (LOI) of these PANOF plain weave fabric samples was 31%, which meets the criterion of flame-retardant fabrics. These fabrics neither melt nor shrunk when left in flame for a short period of time and the fabric structures were well maintained. Compared with flammable polyacrylonitrile fabrics, the polyacrylonitrile pre-oxidation fabrics exhibited excellent flame retardation properties, with satisfactory mechanical properties and comfortable handle.


1993 ◽  
Vol 11 (5) ◽  
pp. 442-456 ◽  
Author(s):  
Jun Zhang ◽  
Michael E. Hall ◽  
A. Richard Horrocks

This paper is the first in a series of four which investigates the burning behaviour and the influence of flame retardant species on the flam mability of fibre-forming polymer and copolymers of acrylonitrile. A pressed powdered polymer sheet technique is described that enables a range of polymer compositions in the presence and absence of flame retardants to be assessed for limiting oxygen index, burning rate and char residue deter minations. The method offers a rapid, reproducible and convenient means of screening possible flame retardant systems, and LOI values compare favourably with those of films and fabrics comprising the same polymeric type. Burning rates, however, are sensitive to changes in physical sample character such as form (film vs. powder sheet) and density. Thus the technique forms an excellent basis for the generation of burning data which will enable comprehensive studies of acrylic polymer flammability and flame retardancy to be undertaken.


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2007 ◽  
Author(s):  
Xianqing Xiong ◽  
Yiting Niu ◽  
Zhuorong Zhou ◽  
Jie Ren

A new design adhesive mixed with flame retardant was developed by an optimized and modified dedicated flame retardant and selected at a suitable proportion between the adhesive and flame retardant as well as the coating amount of the adhesive. The new design adhesive was applied to ecological board production, and the flame-retardant properties of products were examined. The dipping and peeling properties, surface bonding strength, and formaldehyde emission reached the national standard GB/T 34722-2017, the flame retardancy meets the requirements of GB/T 8626-2017, GB/T 20284-2006, GB/T20285-2006, and it also reaches the B1-C level (the nonflammable level in the flame retardant level). This study not only has theoretical guidance but also has strong practical value to provide a basis and data support for the research and development of flame-retardant ecological boards.


2015 ◽  
Vol 30 (6) ◽  
pp. 816-826 ◽  
Author(s):  
Yiren Huang ◽  
Jianwei Yang ◽  
Zhengzhou Wang

Flame-retardant properties of ammonium polyphosphate (APP) and its two microcapsules, APP with a shell of melamine–formaldehyde (MF) resin (MFAPP) and APP with a shell of epoxy resin (EPAPP), were studied in styrene–butadiene–styrene (SBS). The results indicate that APP after the microencapsulation leads to an increase in limiting oxygen index in SBS compared with APP. When dipentaerythritol is incorporated into the SBS composites containing the APP microcapsules, a further improvement in flame retardancy of the composites is observed. The microencapsulation does not result in much improvement of mechanical properties. Moreover, the effect of a compatibilizer (SBS grafted with maleic anhydride) on flame-retardant and mechanical properties of SBS/APP composites was investigated.


2007 ◽  
Vol 1007 ◽  
Author(s):  
Yue Huo ◽  
Qinguo Fan ◽  
Nicholas A Dembsey ◽  
Prabir K Patra

ABSTRACTA phenyl-containing highly cross linked polyborosiloxane (PBSiO) was synthesized as a flame retardant for polyethylene terephthalate (PET). We coated montmorillonite (MMT) clay, a very high aspect ratio and high specific surface area layered silicate with synthesized PBSiO to introduce synergism in flame retardation to the PET nanocomposite film that retained thermal and mechanical properties. This PBSiO has high thermal stability at the processing temperature (270-285° C) of PET and acts as a compatibilizer between PET and clay that are otherwise incompatible. During burning, the flame retardant PET containing PBSiO and MMT forms a protective borosilicatecarbonaceous intumescent char on the surface. Cone calorimeter tests were performed to evaluate key fire properties of the PET/PBSiO/MMT. The peak heat release rate (PHRR) of PET that contains 5 wt% PBSiO and 2.5 wt% MMT was reduced by 60% and similar trend in the reduction of mass loss rate of the nanocomposite was observed.


2020 ◽  
Vol 15 ◽  
pp. 155892502090132
Author(s):  
Sang-Hoon Lee ◽  
Seung-Won Oh ◽  
Young-Hee Lee ◽  
Il-Jin Kim ◽  
Dong-Jin Lee ◽  
...  

To prepare flame-retardant epoxy resin, phosphorus compound containing di-hydroxyl group (10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phospha phenanthrene-10-oxide, DOPO-HQ) was reacted with uncured epoxy resin (diglycidyl ether of bisphenol A, YD-128) and then cured using a curing agent (dicyandiamide, DICY). This study focused on the effect of phosphorus compound/phosphorus content on physical properties and flame retardancy of cured epoxy resin. The thermal decomposition temperature of the cured epoxy resins (samples: P0, P1.5, P2.0, and P2.5, the number represents the wt% of phosphorus) increased with increasing the content of phosphorus compound/phosphorus (0/0, 19.8/1.5, 27.8/2.0, and 36.8/2.5 wt%) based on epoxy resin. The impact strength of the cured epoxy resin increased significantly with increasing phosphorus compound content. As the phosphorus compound/phosphorus content increased from 0/0 to 36.8/2.5 wt%, the glass transition temperature (the peak temperature of loss modulus curve) increased from 135.2°C to 142.0°C. In addition, as the content of phosphorous compound increased, the storage modulus remained almost constant up to higher temperature. The limiting oxygen index value of cured epoxy resin increased from 21.1% to 30.0% with increasing phosphorus compound/phosphorus content from 0/0 to 36.8/2.5 wt%. The UL 94 V test result showed that no rating for phosphorus compounds less than 19.8 wt% and V-1 for 27.8 wt%. However, when the phosphorus compound was 36.8 wt%, the V-0 level indicating complete flame retardancy was obtained. In conclusion, the incorporation of phosphorus compounds into the epoxy chain resulted in improved properties such as impact strength and heat resistance, as well as a significant increase in flame retardancy.


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