New application for aromatic Schiff base: High efficient flame-retardant and anti-dripping action for polyesters

Journal of Engineered Fibers and Fabrics

2019

Layer-by-layer assembly is a simple and effective method which has been widely studied to improve the flame retardancy of textiles in recent years. In this article, flame-retardant and anti-dripping polyethylene terephthalate fabrics were successfully prepared by layer-by-layer assembly branched polyethylenimine and ammonium polyphosphate on their surface. The results of limiting oxygen index values and vertical burning test revealed that the flame retardancy and anti-dripping performance of polyethylene terephthalate fabrics were improved after the layer-by-layer assembly treatment; especially, the dripping phenomenon was eliminated when the number of branched polyethylenimine/ammonium polyphosphate bilayers was over 10. The influence of alkali treatment of polyethylene terephthalate fabrics before layer-by-layer assembly was also investigated. The results showed that alkali treatment of the polyethylene terephthalate fabrics would promote the combination of polyethylene terephthalate fabrics and the charged flame retardants indicating better flame retardancy. The results of thermogravimetric analysis revealed that layer-by-layer assembly treatment of polyethylene terephthalate fabrics would promote char formation both under the nitrogen atmosphere and under the air atmosphere which may act through condensed phase action. The scanning electron microscopy images of the char residues revealed that the layer-by-layer assembly treatment of polyethylene terephthalate fabrics would promote the formation of a compact and intact char residue, which was beneficial for the improvement of flame retardancy and anti-dripping performance. This research would provide the experimental basis for the effective flame retardancy and anti-dripping performance of polyethylene terephthalate fabric.

Section: Introductionmentioning

confidence: 99%

Layer-by-layer assembly flame-retardant and anti-dripping treatment of polyethylene terephthalate fabrics

Fang

Liu

Journal of Engineered Fibers and Fabrics

2019

“…In Figure 2A, different from the FTIR spectra of APTES and APP, a new absorption peak at 1540 cm −1 ascribed to the bending absorption of NH 3 + appears in the FTIR spectrum of APTES‐APP, meaning the occurrence of ion exchange reaction between APP (NH 4 + ) and APTES (NH 2 ) 10,18 . In Figure 2B, in contrast to the FTIR spectra of DPSD, BD‐TES, APTES‐APP and SP‐APP, two new absorption peaks at 1645 cm −1 and 1000 to 1200 cm −1 are presented in the FTIR spectrum of SP‐APP, which are assigned to C=N and Si‐O‐Si, respectively 23,24 . The intensity of characteristic absorption peak of the hydroxyl attached to silicon (SiOH) at 3200 cm −1 decreases apparently.…”

Section: Resultsmentioning

confidence: 88%

“…Similar result is also found in the N1s spectrum in Figure 7B, where the binding energy of CN (399.3 eV) disappears and converts to that of CN (400.0 eV) and pyridine‐like nitrogen structure (398.3 eV) with higher thermal stability due to the crosslinking behavior of Schiff base structure during the pyrolysis process. The formed structures take effect on improving the flame retardancy of PA6 on condensed phase 19,23 . Besides, the peaks at around 401.5, 400.4, and 399.7 eV corresponding to the NH 4 + , NH 3 + , and NH 2 groups, which can be observed in the N1s spectrum of original PA6/SP‐APP‐3, disappear in the N1s spectrum of the residues from Figure 7b2.…”

Section: Resultsmentioning

confidence: 95%

A novel organic‐inorganic flame retardant of ammonium polyphosphate chemically coated by Schiff base‐containing branched polysiloxane for polyamide 6

Fan

Sun

Polymers for Advanced Techs

et al. 2020

A novel organic-inorganic flame retardant (SP-APP) was first designed by coating ammonium polyphosphate (APP) with Schiff base-containing branched polysiloxane via ion exchange reaction and dehydration-condensation. High water resistance and charring capacity of the SP-APP greatly overcame the poor water resistance of APP and endowed polyamide 6 (PA6) with excellent flame retardancy and anti-dripping. The prepared PA6/SP-APP composite with 12 wt% of SP-APP reached the highest limited oxygen index (LOI) of 32.5% and passed V-0 rating of UL-94 test with nondripping, while PA6 and PA6/APP with 12 wt% of APP failed to pass the UL-94 test. A sharp reduction of 50.9% in peak heat release rate (PHRR) and 29.4% in total heat release (THR) was found for PA6/SP-APP in contrast with PA6. The working mechanism of SP-APP in enhancing the flame retardancy of PA6 was also explored intensively and the synergistic effects of catalytic degradation of APP, self-crosslinking behavior of Schiff base structure and thermo-oxidative degradation of branched polysiloxane contributed to the improvement of flame retardancy of PA6/SP-APP.

“…However, high flammability and severe melt dripping limit its application in many fields . Therefore, many methods, such as copolymerization, flame‐retardant coatings, and melt blending have been developed to solve this problem, of which melt blending is most commonly used . Traditional halogen‐based flame retardants have gradually been unacceptable because of their harmful hydrogen halides release, and current flame retardant development mainly focuses on halogen‐free flame retardant .…”

Section: Introductionmentioning

confidence: 99%

Polyphosphazene microspheres modified with transition metal hydroxystannate for enhancing the flame retardancy of polyethylene terephthalate

Polymers for Advanced Techs

et al. 2020

A novel PZS@CS hybrid structure was synthesized for enhancing the flame retardancy of polyethylene terephthalate (PET). The PZS@CS hybrids showed significant flame retardance. For example, the incorporation of 6 wt% PZS@CS obviously brought about an 8.8% increase of limiting oxygen index value (29.3%) and passed the vertical burning test UL-94 V-0 level, accompanied with the sharp reduction of heat and smoke release. The flame retardant mechanism of PZS@CS hybrids was fully studied by the Thermogravimetric Analysis (TGA), pyrolysis-gas chromatography-mass spectrometry, and Raman methods, and the results showed that the improvement of flame retardancy was mainly ascribed to the synergistic effect of PZS and CS phases in both the condensed and the gas phase. Rheological results showed that PZS@CS hybrids improved the melt complex viscosity of PET composites and the well compatibility of PET matrix and PZS@CS hybrids was also proved by the improvement of mechanical properties. K E Y W O R D SCoSn(OH) 6 , flame retardant, PET, polyphosphazene, self-assembly