Novel intumescent flame retardant polypropylene (PP) composites were prepared based on a char forming agent (CFA) and silica-gel microencapsulated ammonium polyphosphate (Si-MCAPP). The thermal and flame retardancy of flame retardant PP composites were investigated by limiting oxygen index, UL-94 test, cone calorimetry, thermogravimetric analysis, scanning electron micrograph, and water resistance test. The results of cone calorimetry show that the flame retardant properties of PP with 30 wt% novel intumescent flame retardants (CFA/Si-MCAPP = 1:3) improve greatly. The peak heat release rate and total heat release decrease, respectively, from 1,140.0 to 156.8 kW m?2 and from 96.0 to 29.5 MJ m?2. The PP composite with CFA/Si-MCAPP = 1:3 has the excellent water resistance, and it can still obtain a UL-94 V-0 rating after 168 h soaking in water. 相似文献
The smoldering weakness of alginate fibers can be effectively suppressed by simple blending with flame retardant viscose fibers. The char formed by flame retardant viscose fibers can prevent the heat transmission and suppress the smoldering of alginate. 相似文献
A char-forming agent (CFA) and silica-gel-microencapsulated ammonium polyphosphate (MCAPP) were selected to form novel intumescent flame retardant system (IFRs), and then the influence of this novel IFRs on the thermal and flame retardant properties of low-density polyethylene (LDPE) were studied. The results of cone calorimetry show that the flame retardant properties of LDPE with 30?wt% novel IFR (CFA/MCAPP?=?1:3) improve remarkably. The heat release rate peak, total heat release (THR) decreases, respectively, from 1479.6 to 273.5?kW?m?2 and from 108.0 to 80.5?MJ?m?2. The LDPE composite with CFA/MCAPP?=?1:3 has the excellent water resistance, and it can still obtain a UL-94?V-0 rating after treated with water at 70?°C for 168?h. 相似文献
A systematic investigation of structurally identical flame retardant viscose, modal and polyester blended fabrics and fibres was carried out in order to develop a chemical basis for more effective products based on organic and inorganic flame retardants. The oxygen indices and chemical compositions of phosphorus-nitrogen flame retardants (P-N) were used in efficiency and synergy evaluations. A new flame retardant viscose fibre containing silicid acid was included in the comparative evaluation procedure. Thermal gravimetry and X-ray diffractometry were used for determine physical factors during pyrolyzing of fibres. Charred residues were analyzed by applying elementary and solid 13-C NMR (CPMAS) spectrometry. The pyrolysis gas-liquid chromatographer connected with a gas phase FT infrared spectrometer was applied to identify the decomposition products of P-N-containing fabrics. 相似文献
Effective additives are required to impart a measure of fire retardancy to polymeric materials used in a variety of applications.
Traditionally, these have been gas-phase active additives, most commonly organohalogen compounds, or solid-phase active agents,
often organophosphorus compounds. Organosphosphorus flame retardants are often very effective but may suffer from a cost disadvantage
when compared with their organobromine counterparts. Organohalogen flame retardants are usually quite effective but their
use is subject to several environmental concerns. The development of additives that could simultaneously promote both types
of fire retardant action could make available flame retardants that are both more cost effective and more environmentally
friendly than those currently in use. Several sets of compounds including bromoanilino triazine derivatives and bromoaryl
phosphates with the potential to display both solid-phase and gas-phase flame retardant activity have been prepared and evaluated
by a variety of thermal methods. 相似文献
The degradation kinetics
of polycarbonate with flame retardant additive was investigated by means of
thermogravimetric analysis. The samples were heated from 30 to 900°C in
nitrogen atmosphere, with three different heating rates: 5, 10 and 20°C
min–1. The Vyazovkin model-free kinetics
method was applied to calculate the activation energy (Ea)
of the degradation process as a function of conversion and temperature. The
results indicated that the polycarbonate without flame retardant additive
starts to loose mass slightly over 380°C and the polycarbonate with flame
retardant additive, slightly over 390°C (with heating rate of 5°C
min–1). The activation energy for flame retardant
polycarbonate and normal polycarbonate were 190 and 165 kJ mol–1,
respectively. 相似文献
Pentaerythritol diphosphonate melamine-urea-formaldehyde resin salt, a novel cheap macromolecular intumescent flame retardants
(IFR), was synthesized, and its structure was a caged bicyclic macromolecule containing phosphorus characterized by IR. Epoxy
resins (EP) were modified with IFR to get the flame retardant EP, whose flammability and burning behavior were characterized
by UL 94 and limiting oxygen index (LOI). 25 mass% of IFR were doped into EP to get 27.2 of LOI and UL 94 V-0.
The thermal properties of epoxy resins containing IFR were investigated with thermogravimetry (TG) and differential thermogravimetry
(DTG). Activation energy for the decomposition of samples was obtained using Kissinger equation. The resultant data show that
for EP containing IFR, compared with EP, IFR decreased mass loss, thermal stability and Rmax, increased the char yield. The activation energy for the decomposition of EP is 230.4 kJ mol−1 while it becomes 193.8 kJ mol−1 for EP containing IFR, decreased by 36.6 kJ mol−1, which shows that IFR can catalyze decomposition and carbonization of EP. 相似文献
Water blown rigid polyurethane foam (PUF) was prepared with melamine polyphosphate (MPP) and melamine cyanurate (MC) as fire retardant (FR) additives. The effect of these additives on the properties of rigid PUF such as physico-mechanical, morphological, thermo-oxidative stability, flame retardancy and smoke density properties were studied. The mechanical and thermo-oxidative stability of PUF filled with MC was found to be better than those of MPP filled PUF. The insulation property of both MPP and MC filled PUF was improved with respect to the neat PUF. The FR properties of these filled PUF were evaluated by cone calorimeter, limiting oxygen index (LOI), smoke density, rate of burning and char residue estimation. The FR property of MPP filled PUF was better than that of the MC filled PUF. 相似文献
Journal of Thermal Analysis and Calorimetry - In the present work, pyrolysis kinetic mechanism was studied for regenerated cellulosic fiber (RCF) and composite RCF containing silicon/nitrogen flame... 相似文献
Functional materials prepared from natural resources arouse a great interest recently. Herein, a novel natural material based flame retardant chitosan phosphate acrylate (GPCS) containing phosphorus and acrylate structure has been prepared. Its effect on thermal properties and combustion behaviors of epoxy acrylate (EA) has been investigated. Microscale combustion calorimeter (MCC) data showed that GPCS reduced the peak heat release (PHRR) and total heat release (THR) of samples greatly, which meant that GPCS was efficient in reducing the flammability of EA. The results of thermogravimetric analysis (TGA) exhibited that GPCS improved the thermal stability of materials at high temperature. Investigation of real time Fourier transform infrared (RT-IR) and thermogravimetric analysis/infrared spectrometry (TGA-IR) revealed that GPCS promoted the formation of char and reduced the release of combustible gas. Thermomechanical properties data showed that the storage modulus of samples increased then decreased with increasing GPCS content while the glass transition temperature continued reduced. 相似文献
The present investigation describes the preparation of nano-SiO2-phenolic novolac resin nanocomposite through in situ polymerisation. CP MAS 13C NMR and FTIR analyses indicate the formation of chemical linkage between the inorganic and organic components. The decomposition temperature of the nanocomposite is ∼70 °C higher than the neat phenolic resin. The char content of the nanocomposite at any intermediate temperature is higher than that of neat resin. The limiting oxygen index value of the neat resin is 38 whereas it is 43 for the nanocomposite. So, the nanocomposite possesses excellent flame retardant property. Both the nanocomposite and the neat resin were isothermally pyrolysed and the products were separated and identified using GC–MS. The decomposition product analysis shows a difference in the decomposition product distribution. This variation is discussed in the light of the proposed structure for the SiO2-phenolic nanocomposite. 相似文献
A novel cheap macromolecular intumescent flame retardants (MIFR) was synthesized, and its structure was a macromolecule containing phosphorus characterized by IR. Rigid polyurethane foam (PUF) filled with MIFR as fire retardant additive was prepared. The effects of MIFR on properties such as density, compressive strength, flame-retardant behavior, thermal stability, and morphology of char were studied. The compressive strength of the MIFR-filled PUF increased initially and then decreased with further increase of MIFR content while its density straightly increased. Its flammability and burning behavior were characterized by UL 94 and limiting oxygen index (LOI). Twenty five percent of MIFR was doped into PUF to get 24.5 of LOI and UL 94 V-0. Activation energy for the decomposition of samples was obtained using Kissinger equation. The resultant data show that for PUF containing MIFR, compared with PUF, the mass loss, thermal stability, and the decomposition activation energy decreased, the char yield increased, which shows that MIFR can catalyze decomposition and carbonization of PUF to form an effective charring layer to protect the underlying substrate. 相似文献
Nanoflaky manganese phosphate (NMP) was synthesized from manganese nitrate and trisodium phosphate dodecahydrate, and used as a synergistic agent on the flame retardancy of polypropylene (PP)/intumescent flame retardant (IFR) system. The thermogravimetric analysis (TGA), real time Fourier-transform infrared (RTFTIR) spectroscopy measurements, cone calorimeter (CONE) and microscale combustion calorimeter (MCC) were used to evaluate the synergistic effects of NMP on PP/IFR system. When IFR + NMP was fixed at 20 wt% in flame retardant PP system, the TGA tests showed that NMP could enhance the thermal stability of PP/IFR system at initial temperature from about room temperature to 440 °C and effectively increase the char residue formation. The RTFTIR results revealed that NMP could clearly change the decomposition behavior of PP in PP/IFR system, which promotes decomposition at the initial temperature from about room temperature to 260 °C and forms more effective barrier layer to protect PP from decomposing at high temperature from about 260 °C to 500 °C. The CONE tests indicated that the addition of NMP in PP/IFR system not only reduced the peak heat release rate (HRR), but also prolonged the ignition time. The MCC results revealed that PP/IFR/NMP system generated less combustion heat over the course of heating than that of PP/IFR system. And scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to explore the char residues of the PP/IFR systems with and without NMP. 相似文献
The combination of synergistic agent with intumescent flame retardant (IFR) systems provides a promising way to prepare high performance IFR composites. In this study, the effects of the synthetic zeolite 4 A in combination with the IFR system consisting of ammonium polyphosphate (APP) and tris (2-hydroxyethyl) isocynurate (THEIC) on thermal degradation, mechanical properties, flame retardancy and char formation of high-density polyethylene composites were investigated by limiting oxygen index (LOI) measurement, cone calorimetry, scanning electron microscopy and laser Raman spectroscopy. The LOI value of HD/FR/Z-0.5 composite with an optimum content of 0.5 wt. % zeolite 4 A and 25 wt. % of total flame retardant reaches 26.3 %. A low loading of zeolite 4 A can improve the bench-scale combustion performance as determined by cone calorimetry, and promote the formation of more compact char residue with a highly graphitic structure. However, a low loading of zeolite in combination with the IFR system consisting of APP and THEIC produces no significant changes in mechanical performance. 相似文献
How to improve the flame retardancy of lyocell fibers has become an important issue in textile industry. Herein, lyocell fibers were firstly undergone etherification reaction between sodium chloroacetate and the hydroxyl groups of lyocell fibers to obtain carboxymethylated lyocell fibers (CM-lyocell), then the sodium ions of CM-lyocell were replaced by aluminum ions, and the flame retardant lyocell fibers (FR-lyocell) were prepared. Compared with lyocell fibers, the degradation temperature of FR-lyocell decreased by about 80 °C, and the char residue in nitrogen increased from 15.1 to 31.8 wt% at 800 °C. Importantly, the limiting oxygen index (LOI) value of FR-lyocell fabric was increased from 17.2 to 26.4%. Besides, the peak of heat release rate (PHRR) and total heat release (THR) of FR-lyocell had 77.4% and 76.3% reduction, respectively. The FR-lyocell can generate a highly graphitized char layer and release more water at high temperatures, which are beneficial to improving the flame retardancy of lyocell fibers. Moreover, the tensile test showed that the tensile strength of FR-lyocell decreased from 3.95 to 3.08 cN/dtex with a 22% reduction, showing good strength retention.