scholarly journals Potential Synergism between Novel Metal Complexes and Polymeric Brominated Flame Retardants in Polyamide 6.6

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1543 ◽  
Author(s):  
Alistair F. Holdsworth ◽  
A. Richard Horrocks ◽  
Baljinder K. Kandola
Keyword(s):  
Flame Retardants ◽  
Vapour Phase ◽  
Environmental Concerns ◽  
Antimony Trioxide ◽  
Release Rates ◽  
Cone Calorimetry ◽  
Phosphorus Containing ◽  
Brominated Polystyrene ◽  
Polyamide 6.6 ◽  
Phase Activity

While environmental concerns have caused polymeric brominated primary flame retardants (PolyBrFRs) to be effective replacement monomeric species, few alternatives for antimony trioxide (ATO) have been developed beyond the zinc stannates (ZnSs). Previous research, which explored the interactions of aluminium (AlW), tin (II) (SnW) and zinc (ZnW) tungstates with several phosphorus-containing flame retardants in polyamide 6.6 (PA66), is extended to two PolyBrFRs: brominated polystyrene (BrPS), and poly(pentabromobenzyl acrylate) (BrPBz). On assessing the effect of each tungstate on the thermal degradation and flammability in combination with each PolyBrFR using TGA, UL94, LOI, cone calorimetry and TGA-FTIR, only ZnW and SnW showed significant increases in LOI (>26 vol.%). Both ZnW-BrPS- and ZnW-BrPBz-containing formulations yielded average UL94 ratings ≥ V-2 and TGA char residues (corrected for metals content at 500 °C) in air > 15 wt.%. BrPS-containing samples, especially those containing ZnW and SnW, generated peak heat release rates approximately 50% lower than the equivalent BrPBz samples. These reductions did not correlate with respective increases in LOI, suggesting that tungstate-PolyBrFR combinations influence pre-ignition differently to post-ignition behaviour. Calculated synergistic effectivities indicate that ZnW functions as a synergist in both pre- and post-ignition stages, especially with BrPS. TGA-FTIR and char analyses showed that, in addition to the vapour-phase activity normally associated with PolyBrFRs, condensed-phase processes occurred, especially for the ZnW-PolyBrFR combinations. Additionally, ZnW demonstrated significant smoke-suppressing properties comparable with zinc stannate (ZnS).

scholarly journals Phosphorus-Containing Silsesquioxane Derivatives as Additive or Reactive Components of Epoxy Resins

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5373
Author(s):  
Mariusz Szołyga ◽  
Michał Dutkiewicz ◽  
Marek Nowicki ◽  
Kamila Sałasińska ◽  
Maciej Celiński ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Hybrid Materials ◽  
Flame Retardants ◽  
Epoxide Ring ◽  
Cone Calorimetry ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Phosphorus Containing ◽  
The Impact ◽  
Phosphate Groups

Two phosphorus-containing cage-like silsesquioxane derivatives were synthesized as reactive or additive flame retardants for epoxy resin. The silsesquioxanes were obtained via an epoxide ring-opening reaction using a 10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPA). In one derivative containing in its structure 4 glycidoxypropyl and 4 phosphate groups, denoted as 4P4GS, only half of the epoxy rings was reacted with phosphate to obtain a reactive additive, while in the second derivative containing 8 phosphate groups, denoted as 8PS, all epoxy groups were converted, thus an additive modifier was obtained. The silsesquioxanes containing phosphorus atoms and the reactive phosphorus-free silsesquioxane derivative (octakis[(3-glycidoxypropyl)dimethylsiloxy]octasilsesquioxane (8GS)) were used to prepare hybrid materials based on epoxy resin. To compare the impact of the structure of silsesquioxane derivatives on the properties of hybrid materials, a number of samples containing 1, 5, and 10% of the modifiers making a series of epoxy materials containing additive or reactive modifiers, were obtained. The modified epoxies were studied using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), nanoindentation, water contact angle, and cone calorimetry tests to assess the effects of the modifier structure on the physicochemical properties of the investigated materials.

scholarly journals Phosphorus-Containing Flame Retardants from Biobased Chemicals and Their Application in Polyesters and Epoxy Resins

Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3746 ◽  
Author(s):  
Jacob Sag ◽  
Daniela Goedderz ◽  
Philipp Kukla ◽  
Lara Greiner ◽  
Frank Schönberger ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Renewable Resources ◽  
Epoxy Resins ◽  
Flame Retardants ◽  
Oxygen Index ◽  
Polymer Structure ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index ◽  
Phosphorus Containing ◽  
Biobased Chemicals

Phosphorus-containing flame retardants synthesized from renewable resources have had a lot of impact in recent years. This article outlines the synthesis, characterization and evaluation of these compounds in polyesters and epoxy resins. The different approaches used in producing biobased flame retardant polyesters and epoxy resins are reported. While for the polyesters biomass derived compounds usually are phosphorylated and melt blended with the polymer, biobased flame retardants for epoxy resins are directly incorporated into the polymer structure by a using a phosphorylated biobased monomer or curing agent. Evaluating the efficiency of the flame retardant composites is done by discussing results obtained from UL94 vertical burning, limiting oxygen index (LOI) and cone calorimetry tests. The review ends with an outlook on future development trends of biobased flame retardant systems for polyesters and epoxy resins.

Study of the Combustion and Fire Retardancy of Polyacrylonitrile and Its Copolymers by Using Cone Calorimetry

1995 ◽  
Vol 13 (2) ◽  
pp. 141-161 ◽  
Author(s):  
J. Zhang ◽  
G.W.H. Silcock ◽  
T.J. Shields
Keyword(s):  
Heat Release ◽  
Flame Retardants ◽  
High Efficiency ◽  
Ammonium Polyphosphate ◽  
Diphenyl Oxide ◽  
Fire Retardancy ◽  
Release Rates ◽  
Cone Calorimetry ◽  
Rapid Decomposition ◽  
Initial Peak

The combustion and fire retardancy behaviour of polyacryloni trile and its fibre-forming copolymers have been studied using the cone calorimetry technique. The heat release rates of the polymers are characterised by two high peaks. The first one occurs at the beginning of flaming combustion while the other occurs close to extinction. However, the initial peak is sig nificantly reduced by the addition of comonomers such as methyl acrylate and vinyl acetate, or flame retardants such as ammonium polyphosphate. The study shows that the high initial peak during combustion is closely related to the intensive exotherm of the polymers during pyrolysis. It is suggested that the intensive exotherm leads to rapid decomposition of the polymer chains and consequently results in the high initial peak of heat release rates. The two selected flame retardants, ammonium polyphosphate (APP) and decabromo diphenyl oxide (Deca) show a high efficiency in reducing the heat release rates. The APP mainly reduces the initial peak while Deca diminishes the last peak significantly, demonstrating two completely different retarding mechanisms.

scholarly journals A bio-based phosphaphenanthrene-containing derivative modified epoxy thermosets with good flame retardancy, high mechanical properties and transparency

RSC Advances ◽  
2021 ◽  
Vol 11 (49) ◽  
pp. 30943-30954
Author(s):  
Wei Peng ◽  
Yu-xuan Xu ◽  
Shi-bin Nie ◽  
Wei Yang
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Epoxy Resins ◽  
Flame Retardants ◽  
The Past ◽  
Phosphorus Containing ◽  
Modified Epoxy

Phosphorus-containing flame retardants have received huge interest for improving the flame retardant behavior of epoxy resins (EP) over the past few decades.

Novel phosphorus-containing silazanes as flame retardants in epoxy resins

2021 ◽  
pp. 105120
Author(s):  
Philipp Kukla ◽  
Lara Greiner ◽  
Sebastian Eibl ◽  
Manfred Döring ◽  
Frank Schönberger
Keyword(s):  
Epoxy Resins ◽  
Flame Retardants ◽  
Phosphorus Containing

Interference of Sb(III) in the Determination of Hexavalent Chromium in Thermoplastic Matrices

2011 ◽  
Vol 2011 (1) ◽  
pp. 000345-000351
Author(s):  
Sophia S. Lau ◽  
Joe P. Kuczynski
Keyword(s):  
Hexavalent Chromium ◽  
Flame Retardants ◽  
Test Method ◽  
Polymer Matrices ◽  
Antimony Trioxide ◽  
False Negatives ◽  
Total Chromium ◽  
Adverse Health Effects ◽  
The Eu

Due to the adverse health effects of hexavalent chromium, Cr(VI), pigments and other materials containing Cr(VI) were largely banned for use in electrotechnical products under the EU RoHS Directive [1]. While there are several effective methods to determine the presence of total chromium in electrotechnical plastic matrices, a validated compliance test method that is capable of discerning Cr(VI) from the non-regulated forms of Cr(III) is not yet available. One of the challenges in developing a standardized compliance test for Cr(VI) is the low recovery of Cr(VI) compounds from polymer matrices This study identified antimony trioxide (ATO), a common synergist added to enhance the ignition resistance of brominated flame retardants (BFRs), as a source of matrix interference in the quantitative determination of hexavalent chromium extracted from polymer matrices. ATO reduces hexavalent chromium to trivalent chromium prior to complexation of Cr(VI) with diphenylcarbazide (DPC) leading to false negatives. EDTA was found to be an efficient reagent for Sb(III) complexation, thereby suppressing the reduction of Cr(VI) and enabling quantitative Cr(VI) determination in the presence of ATO.

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