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Retardancy
Kinds of Retardancy Selected AbstractsNovel Phosphorus-Containing Poly(ether sulfone)s and Their Blends with an Epoxy Resin: Thermal Decomposition and Fire RetardancyMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 16 2006Ulrike Braun Abstract Summary: The decomposition of novel phosphorus-containing poly(oxyphenylene-sulfonyl-phenylene-oxy-diphenyl phenylene phosphine oxide) (PSU_I), 2,5-dihydroxy-1-biphenylene-phosphine oxide based polysulfone (PSU_II), poly(sulfonyl-diphenylphenylene phosphonate) (PSU_P) and bisphenol A-based polysulfone (PSU) is studied. The influence of the chemical structure, charring and phosphorus release is discussed based on the mass loss, kinetics and products. The pyrolysis and fire behaviour of blends with epoxy resin (EP) are studied. For EP-PSU_II, phosphorus initiates water elimination and changes the decomposition pathway of EP. The fire behaviour of EP-PSU shows some improvements, whereas the heat release rate is crucially reduced for EP-PSU_II due to simultaneous char formation and flame inhibition. Decomposition model of PSU_II. [source] Zinc hydroxystannate-coated metal hydroxides as flame retardant and smoke suppression for flexible poly vinyl chlorideFIRE AND MATERIALS, Issue 4 2009Hongqiang Qu Abstract Zinc hydroxystannate (ZHS)-coated metal hydroxides were prepared. The effects of ZHS-coated metal hydroxides on flame retardancy and smoke suppression of flexible poly vinyl chloride were studied by means of the limiting oxygen index, smoke density rating and the char yield test. The mechanism was investigated by thermogravimerty (TG), differential thermal analysis, and differential TG analysis and scanning electron microscopy. The results showed that ZHS-coated metal hydroxides are more effective flame retardant and smoke suppressant than metal hydroxides, and it appears that tin compound may exert its action in both the condensed and vapor phases, but mainly in condensed phases as a Lewis acid. Copyright © 2009 John Wiley & Sons, Ltd. [source] The application of a novel flame retardant on viscose fiberFIRE AND MATERIALS, Issue 3 2009Jiang-tao Hu Abstract The paper is mainly about a novel organophosphorus flame-retardant N-1-chloroisopropyl alcohol-3-dimethylphosphonopropionamide. Dimethyl phosphate, acrylamide and epichlorohydrin were used as raw materials. The mechanisms of synthesis and molecule structure of the flame retardant were discussed. The fiber was treated using the pad-dry-cure-wash method. The limiting oxygen index value of the modified sample was 31%, higher than that of the sample treated with MDPA (Pyrovatex CP). After 50 laundry cycles, it still had some flame retardancy left. Thermogravimetry (TG) and Differentiate TG analyses confirmed that the flame retardant caused fiber to decompose below its ignition temperature and formed carbonaceous residue or char when exposed to fire. The treatment had an obvious effect on the denier of the fiber; the tensile strength of fiber slightly decreased, but that effect could be negligible. Copyright © 2008 John Wiley & Sons, Ltd. [source] Flame retardation and thermal degradation of flame-retarded polypropylene composites containing melamine phosphate and pentaerythritol phosphateFIRE AND MATERIALS, Issue 5 2008Shun Zhou Abstract The flame retardation of polypropylene (PP) composites containing melamine phosphate (MP) and pentaerythritol phosphate (PEPA) was characterized by limiting oxygen index (LOI) and UL 94. The morphology of the char obtained from the combustion of the composites was studied by scanning electron microscopy (SEM). The thermal degradation of the composites was investigated using thermogravimetric (TG) analysis and real-time Fourier transform infrared (RTFTIR) spectroscopy. It has been found that the PP composites containing only MP do not show good flame retardancy even at 40% additive level. Compared with the PP/MP binary composites, all the LOI values of the PP/MP/PEPA ternary composites at the same additive loading increase, and UL 94 ratings of the ternary composites at suitable MP/PEPA ratios are raised to V-0 from no rating (PP/MP). The TG and RTFTIR studies indicate that the interaction occurs among MP, PEPA and PP. Copyright © 2008 John Wiley & Sons, Ltd. [source] Flame retardancy finish with an organophosphorus retardant on silk fabricsFIRE AND MATERIALS, Issue 6 2006Jin-Ping Guan Abstract The paper mainly deals with flame retardancy of silk fabrics treated with a commercial organophosphorus flame retardant [N-hydroxymethyl (3-dimethyl phosphono) propionamide (HDPP), also known as Pyrovatex CP], using the pad-dry-cure-wash method. The structures and properties of the treated and control sample are discussed. The Limiting Oxygen Index (LOI) value of the modified sample is above 30%. After 50 laundry cycles, it still has some flame retardancy left. HDPP and a cross-linking agent (HMM) were bound to silk fabrics which is confirmed by FT-IR spectra and amino analysis. The reaction degree of the flame retardant with silk is also high; almost all the tyrosine units have reacted, which can be confirmed by amino acid analysis. The reaction between flame retardant and silk only occurs in the amorphous region of silk fibre, which is confirmed by X-ray diffraction analysis and amino acid analysis. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis show that the flame retardant causes silk fabrics to decompose below its ignition temperature (600°C) and formed carbonaceous residue or char when exposed to fire. The char behaves as a thermal barrier to fire, so silk fabrics show good flame retardancy. The treatment has a little effect on the whiteness of the silk fabrics and the tensile strength of treated silk fabrics slightly decreased; both effects are negligible. Copyright © 2006 John Wiley & Sons, Ltd. [source] Polyurethane/clay and polyurethane/POSS nanocomposites as flame retarded coating for polyester and cotton fabricsFIRE AND MATERIALS, Issue 4-5 2002Eric Devaux Polyurethane resins (PU) are widely used as coatings for textile fabrics in order to improve some properties (for example mechanical behaviour, water repellency and air impermeability). Two kinds of additives have been added to the polyurethane in order to provide flame retardancy to the coated textile structure: montmorillonite clay and polyhedral oligomeric silsesquioxanes (POSS) have been used to process PU nanocomposites. The paper presents some results obtained with PU/clay and PU/POSS coated polyester or cotton fabrics, using cone calorimetry and thermogravimetric analysis. The efficiency of the additive chosen is clearly demonstrated and discussed. In particular, the great potential of using POSS for fire retardant applications is highlighted. Copyright © 2002 John Wiley & Sons, Ltd. [source] Flame retardant properties of EVA-nanocomposites and improvements by combination of nanofillers with aluminium trihydrateFIRE AND MATERIALS, Issue 5 2001Günter Beyer Flame retardant nanocomposites are synthesized by melt-blending ethylene,vinyl acetate copolymers (EVA) with modified layered silicates (montmorillonites). Thermogravimetric analysis performed under different atmospheres (nitrogen and air) demonstrated a clear increase in the thermal stability of the layered silicate-based nanocomposites. The use of the cone calorimeter to investigate the fire properties of the materials indicated that the nanocomposites caused a large decrease in heat release. The char-formation is the main factor important for improvement and its function is outlined. Further improvements of the flame retardancy by combinations of nanofillers and traditional FR-additives on the basis of metal hydroxides were also studied. Copyright © 2002 John Wiley & Sons, Ltd. [source] Effect of boron-containing materials on the flammability and thermal degradation of polyamide 6 composites containing melamineJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Mehmet Do Abstract Three different boron-containing substances,zinc borate (ZnB), borophosphate (BPO4), and a boron- and silicon-containing oligomer (BSi),were used to improve the flame retardancy of melamine in a polyamide 6 (PA-6) matrix. The combustion and thermal degradation characteristics of PA-6 composites were investigated with the limiting oxygen index (LOI), the UL-94 standard, thermogravimetric analysis (TGA)/Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC). A slight increase was seen in the LOI values of a sample containing BSi (1 wt %). BPO4 at high loadings showed a V0 rating (indicating the best flame retardancy) and slightly lower LOI values in comparison with samples with only melamine. For ZnB and BSi, glassy film and char formation decreased the dripping rate and sublimation of melamine, and this led to low LOIs. According to the TGA,FTIR results, the addition of boron compounds did not change the decomposition product distribution of melamine and PA-6. The addition of boron compounds affected the flame retardancy by physical means. The TGA data showed that boron compounds and melamine reduced the decomposition temperature of PA-6. According to the DSC data, the inclusion of boron compounds increased the onset temperature of sublimation of melamine and also affected the flame retardancy negatively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Preparation and flame retardancy of 2-EHA/n -BA acrylic PSA containing single and combined flame retardantsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Eun-Young Park Abstract UV curable acrylic PSAs (pressure-sensitive adhesives) were modified with organic and inorganic flame retardants to improve flame retardancy of PSAs minimize the sacrifice of adhesion properties. The flame retardancy (UL-94 test) of acrylic PSAs were enhanced by the addition of 5,30 wt % of an organic flame retardant such as TCEP (Tris(2-chloroethyl)phosphate), PBPE (pentabromophenyl ether), and TBBPA(3,3,5,5,-tetrabromobisphenol A). Especially, TBBPA is the best flame retardant for acrylic PSAs when it works alone. However, PSAs compounded with aluminum trihydroxide (Al(OH)3) showed a little reduction in burning time up to 30 wt %. An apparent synergic effect was observed only for an acrylic PSAs with a combination of TCEP and PBPE flame retardants. The addition of flame retardants brought a no significant effect on curing even in high amount. It was surmised that the miscibility between PSAs and flame retardant was closely related with flame retardancy and adhesion properties of acrylic PSAs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Investigation of flame retardancy and physical,mechanical properties of zinc borate/boric acid polyester compositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Miyaser Demirel Abstract The glass fiber reinforced polyester composite materials were prepared with varying contents of boric acid, zinc borate, and magnesium hydroxide as flame retardants to improve the flame retardancy of the composites. Experimental results showed that boric acid exhibited a good flame retardant effect on the polyester composite. When boric acid content is used as 15 wt %, the Limiting Oxygen Index (LOI) value of the composite reached upto 25.3. The increase in boric acid content from 15 to 30 wt %, the LOI values of composite were enhanced from 25.3 to 34.5 by 9.2 units. The LOI values of the composite samples increased with increasing boric acid content. The smoke density results showed that the addition of glass fiber and flame retardants decreased the smoke density of the unreinforced polyester resin. The mechanical properties of the composites have decreased by the addition of flame retardants. The scanning electron micrographs taken from fracture surfaces were examined. The flame retardants, such as boric acid, were well dispersed in the glass fiber reinforced polyester composites and obviously improved the interfacial interaction between glass fibers and polyester composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Preparation and investigation of ethylene,vinyl acetate copolymer/silicone rubber/clay nanocompositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2009Shoulin Fang Abstract In this article, the combination of silicone rubber (SR) elastomer with synthetic iron montmorillonite (Fe-MMT) to form a kind of new flame-retardant system based on an ethylene,vinyl acetate (EVA) copolymer is first reported. Also, the flame retardancy of the EVA/SR/Fe-MMT hybrid are compared with that of EVA/SR/natural sodium montmorillonite. The structures of the nanocomposites were characterized with X-ray diffraction and transmission electron microscopy. Cone calorimeter tests and thermogravimetric analysis were used to evaluate the flame-retardant properties and thermal stability of the composites, respectively. In addition, tensile tests were carried out with a universal testing machine, and the morphology of the fracture surface was observed with environmental scanning electron microscopy. We found that SR/organophilic montmorillonite (Fe-OMT) was more effective in reducing the primary peak heat release rate of the nanocomposite, and the EVA/SR/Fe-OMT hybrid had a higher thermal stability in the deacetylated polymer than EVA/SR/sodium organophilic montmorillonite. Moreover, the exfoliated EVA/SR/Fe-OMT nanocomposite displayed excellent mechanical properties because of a better dispersion of Fe-OMT in the polymer matrix, and a possible mechanism is discussed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] A study of the novel intumescent flame-retarded PP/EPDM copolymer blendsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008Shun Zhou Abstract Flammability of polypropylene/ethylene,propylene-diene copolymer (PP/EPDM) filled with melamine phosphate (MP) and pentaerythritol phosphate (PEPA) was studied by limiting oxygen index (LOI), UL 94, and cone calorimetry. The thermal degradation of the composites was investigated using thermogravimetric analysis (TG) and real-time Fourier transform infrared spectrum (RT-FTIR), and the mechanical properties of the materials were also studied. It had been found that the PP/EPDM/PEPA/MP composites (PEPM series) showed better flame retardancy than that of the PP/EPDM composites containing MP or PEPA. TG and RT-FTIR studies indicated that the interaction occurs among MP, PEPA, and PP/EPDM. The incorporation of the flame retardants deteriorated the mechanical properties of the materials. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Preparation and properties of epoxy/phenol formaldehyde novolac/hexakis(methoxymethyl)melamine hybrid resins from in situ polymerizationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008Xinghong Zhang Abstract Based on the self-condensation of hexakis(methoxymethyl)melamine (HMMM), the condensation between HMMM and phenol formaldehyde novolac resin (n-PF), and the addition reaction of diglycidyl ether of biphenyl A (DGEBA) and n-PF, a homogeneous, transparent hybrid thermoset was prepared via in situ polymerization of DGEBA, n-PF, and HMMM. No phase separations were observed even for the DGEBA/n-PF/HMMM hybrid thermoset containing 40 wt % HMMM. These hybrid thermosets had high glass-transition temperatures (98,127°C from differential scanning calorimetry and 111,138°C from dynamic mechanical analysis), excellent thermal stability with high 5 wt % decomposition temperatures (>322°C), high char yields (>24 wt %), and improved flame retardancy with high limited oxygen indices (>28.5). The excellent overall properties of these hybrid resins may lead to their applications in high-performance "green" electronic products. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Thermal properties and flame retardancy of polyglycidyloxypropyl silsesquioxane/layered titanate nanocompositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Miyuki Harada Abstract Polyglycidyloxypropyl silsesquioxane, which has an excellent heat resistance, was combined with sheet-like and spherical titanate as nano-fillers. The burning property of the composites was related to the shape of the dispersed titanate. A burning test was carried out according to the UL-94 test method. As a result, though the test specimen burned from one end to the other in the spherical titanate filled composite system, a fire extinguishing property was observed in the sheet-like titanate filled composite system. The extinguishing time of the latter system classified V-0 in the specification test. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Synthesis and characterization of dicyanate monomers containing methylene spacersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008G. Anuradha Abstract The bisphenols containing methylene spacer were prepared by treating eugenol/2-allyl phenol with 2,6-dimethyl phenol/guiacol/o -cresol in the presence of AlCl3. All the bisphenols were converted to their respective cyanate esters by treating with CNBr. The structural confirmation was done by FTIR, 1H NMR, 13C NMR spectral methods, and elemental analysis. Thermal characterization was done by DSC and TGA. DSC transition shows that the Tg is in the range of 208,239°C. The Tg is highest for the cyanate ester Cy(b) with symmetric structure. The Tg of the cured network depends on the length and symmetry of the monomer, Tg being higher for shorter and the para-substituted monomers. The T10 values are in the range of 364,381°C. The char yield is in the range of 47,53%. From the char yield, the limiting oxygen index (LOI) value was determined, which is used to confirm the flame retardancy of the cyanate ester resins. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Formation of new thermosets by the reaction of cyanates with thiophenolsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Monika Bauer Abstract Sulfur-containing aromatic thermosets, mainly consisting of aryloxy- and arylthio-substituted 1,3,5-triazines, have been prepared through the reaction of difunctional cyanates with mono- and difunctional aromatic thiols. A straightforward three-step reaction scheme is proposed and verified by the identification of key substances: (1) the addition of thiol and cyanate groups, (2) the stepwise addition of (thio)imino carbonic esters with one another, and (3) the ring closure of chain-extended (thio)imino carbonic esters to form 1,3,5-triazines. Reactions of types 2 and 3 are associated with an abstraction of phenol or thiophenol, which can enter into reaction 1 again. Characterization of the curing behavior of dicyanate of bisphenol A with thiophenol as well as dimercaptodiphenyl sulfide by differential scanning calorimetry shows that the reaction rates are significantly enhanced by the admixture of thiols to the cyanate. Dynamic mechanical analysis of resulting thermosets showed that large amounts of comonomers can be incorporated into the network resulting in a decrease of glass temperature but increase of fracture toughness. Finally, the fully cured thermosets resulting from the reaction of dicyanate of bisphenol A with different admixtures of dimercaptodiphenyl sulfide were characterized by cone calorimetry to get information about flame retardancy. The flame retardancy is influenced by incorporation of dimercaptodiphenyl sulfide into the triazine network only slightly. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Reactive extrusion to synthesize intumescent flame retardant with a solid acid as catalyst and the flame retardancy of the products in polypropyleneJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Yuan Liu Abstract Reactive extrusion and solid acid catalysis technologies were adopted in the pentaerythritol,melamine phosphate (PER-MP) reaction to synthesize intumescent flame retardant, melamine salt of pentaerythritol phosphate (MPP), which was applied in flame retardant polypropylene (PP). This environment-friendly synthesis method provided a solution to the problems of conventional methods. On one hand, reactive extrusion in a twin screw extruder can effectively mix and transfer viscous materials that usually results in a tough stir in a conventional reactor, and achieve a continuous synthesis process. On the other hand, the solid acid, silicotungstic acid (STA) serving as a catalyst, can maintain a satisfactory conversion even with a low extrusion temperature and a short residence time, thus effectively suppressing foaming in the process of the reaction. Furthermore, without removal like other catalysts in general chemical reactions, STA was kept in produced MPP to constitute a synergism flame retardant system, therefore further improved the flame retardancy. LOI and UL94 test showed that the STA-catalyzed MPP (by reactive extrusion) possessed much better flame retardancy in PP when compared with the noncatalyzed MPP (by reactive extrusion), as well as present commercial MPP (by POCl3 method). In our investigation, the catalytic and synergistic effects of STA, as well as the related factors of the reactive extrusion affecting the conversion of the PER-MP reaction, flame retardancy and mechanical performance of the corresponding flame retardant PP, were systematically investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] A novel thermotropic liquid crystalline copolyester containing phosphorus and aromatic ether moity toward high flame retardancy and low mesophase temperatureJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2010Xiang-Cheng Bian Abstract A series of thermotropic liquid crystalline polyesters containing phosphorus and aromatic ether groups (TLCP-AEs) were synthesized from p -acetoxybenzoic acid (p -ABA), terephthalic acid (TPA), 4,4,-oxybis(benzoic acid) (OBBA), and acetylated 2-(6-oxid-6H-dibenz(c,e) (1,2) oxaphosphorin 6-yl) 1,4-benzenediol (DOPO-AHQ). The chemical structure and the properties of TLCP-AEs were characterized by Fourier-transform spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), thermogravimetry analysis (TGA), scanning electronic microscopy (SEM), polarizing optical microscopy (POM), limiting oxygen index, and UL-94 tests, respectively. The results showed that TLCP-AEs had low and broad mesophase temperatures (230,400 °C). TLCP-AEs also showed excellent thermal stability; their 5%-weight-loss temperatures were above 440 °C and the char yields at 700 °C were higher than 45 wt %. All TLCP-AE polyesters exhibited high flame retardancy with a LOI value of higher than 70 and UL-94 V-0 rating. The SEM observation revealed that TLCP-AEs had good fibrillation ability. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1182,1189, 2010 [source] A phosphorus-containing thermotropic liquid crystalline copolyester with low mesophase temperature and high flame retardanceJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2008Cheng-Shou Zhao Abstract A novel phosphorus-containing thermotropic liquid crystalline copolyester with flexible spacers (P-TLCP-FS) was synthesized by melt transesterification from p -acetoxybenzoic acid (p -ABA), terephthalic acid (TPA), ethylene glycol, and acetylated 2-(6-oxid-6H-dibenz(c,e) (1,2) oxaphosphorin 6-yl) 1,4-benzenediol (AODOPB). The chemical structure and properties of the obtained P-TLCP-FS were characterized by Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1H-NMR), inherent viscosity measurements, differential scanning calorimetry (DSC), thermogravimetry (TGA), polarizing light microscopy (PLM), and X-ray diffraction (XRD) analysis. P-TLCP-FS had inherent viscosities of 0.92,1.12 dL/g and exhibited low and wide mesophase temperatures, ranging from 185 to 330 °C, which can match with the processing temperatures of most conventional polymers and high flame retardancy with a limiting oxygen index value of 70% and UL-94 V-0 rating. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5752,5759, 2008 [source] Crosslinking of a polyacrylate bearing a spiroorthoester pendant group with mixtures of diglycidyl ether of bisphenol A and phosphorus-containing glycidyl derivativesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2007J. Canadell Abstract The cationic crosslinking of a polyacrylate bearing a spiroorthoester pendant group with mixtures of diglycidyl ether of bisphenol A and three phosphorus-containing glycidyl derivatives was carried out with ytterbium triflate as an initiator. The curing process was monitored with Fourier transform infrared spectroscopy. The thermomechanical and thermogravimetric properties were evaluated. The glass transition temperatures of the obtained materials were, in general, above 100 °C. The incorporation of phosphorus into the network increased the limiting oxygen index values, thus improving the flame retardancy of the materials. During crosslinking, all the crosslinked polymers showed slight shrinkage that was much lower than that observed in conventional epoxy resins. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1920,1930, 2007 [source] Preparation and properties of high performance epoxy,silsesquioxane hybrid resins prepared using a maleimide,alkoxysilane compound as a modifierJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 23 2005Ying-Ling Liu Abstract An alkoxysilane compound possessing maleimide moiety (MSM) was prepared from N-(4-hydroxyphenyl)maleimide and 3-glycidoxypropyltrimethoxysilane and was used as a modifier of epoxy resins. In situ curing epoxy resins with MSM resulted in epoxy resins with good homogeneity. Just 5,10 wt % of MSM is sufficient to yield high glass transition temperature (165 °C), good thermal stability above 360 °C, and high flame retardancy (LOI = 30) to bisphenol-A-based epoxy resins. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5787,5798, 2005 [source] Effect of the organophosphate structure on the physical and flame-retardant properties of an epoxy resinJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 3 2002Jeng-Yueh Shieh Abstract 2-(6-Oxido-6H-dibenzo,c,e,,1,2,oxa-phosphorin-6-yl)1,4-benzenediol (ODOPB) and bis(3-dihydroxyphenyl) phenyl phosphate (BHPP) were successfully synthesized and used as reactive flame retardants in o -cresol formaldehyde novolac epoxy resin. Because of the rigid, cyclic, side-chain structure of ODOPB, the resultant phosphorus-containing epoxy resin exhibited a higher glass-transition temperature, better flame retardancy, higher modulus, and greater thermal stability than the regular bromine-containing tetrabromobisphenol A epoxy resin and the linear, main-chain, phosphorus-containing BHPP epoxy resin. A UL-94VO rating was achieved with a phosphorus content as low as 1.1% with ODOPB (comparable to a bromine content of 12% and a phosphorus content of 2.2% with BHPP) in the cured resins, and no fumes or toxic gas emissions were observed. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 369,378, 2002 [source] Thermal behavior and flame retardancy of flexible poly(vinyl chloride) treated with zinc hydroxystannate and zinc stannateJOURNAL OF VINYL & ADDITIVE TECHNOLOGY, Issue 1 2008Weihong Wu The flame-retardant and smoke-suppressant properties of inorganic tin compounds such as zinc hydroxystannate (ZHS) and zinc stannate (ZS) were studied in comparison with those of alumina trihydrate and magnesium hydroxide through the limiting oxygen index test and a smoke density test. The thermal degradation in air of flexible poly(vinyl chloride) (PVC) treated with the above compounds was studied by thermal analysis from ambient temperature to 800°C. The activation energy was calculated by using the Vyazovkin model-free kinetic method and the Kissinger method. The results showed that tin compounds such as ZHS and ZS could be used as highly effective flame retardants for flexible PVC; these flame retardants enhanced the stability and the activation energy of the oxidation of the char. J. VINYL ADDIT. TECHNOL, 2008. © 2008 Society of Plastics Engineers [source] Preparation and Properties of PVC Ternary Nanocomposites Containing Elastomeric Nanoscale Particles and Exfoliated Sodium-MontmorilloniteMACROMOLECULAR MATERIALS & ENGINEERING, Issue 6 2006Qingguo Wang Abstract Summary: A novel rigid PVC ternary nanocomposite containing NBR-ENP and untreated Na-MMT has been fabricated. X-ray diffraction XRD, TEM and SEM observations revealed that the untreated Na-MMT was exfoliated and most NBR-ENPs (about 90 nm) were separately dispersed in the PVC matrix. DMTA and TGA demonstrated that the PVC ternary nanocomposites had a higher glass transition temperature and a higher decomposition temperature than neat PVC, while the toughness increased simultaneously. Combustion tests showed that the exfoliated clay in the PVC/NBR-ENP/MMT ternary nanocomposites did not improve the flame retardancy after ignition under strong heat flux. Schematic diagram of the fabrication procedure of PVC/NBR-ENP/Na-MMT ternary nanocomposites. [source] Use of Turkish huntite/hydromagnesite mineral in plastic materials as a flame retardantPOLYMER COMPOSITES, Issue 10 2010Hüsnügül Y, lmaz Atay In this study, the flame retardancy properties of huntite/hydromagnesite mineral in plastic compounds were investigated for potential electrical applications. Before the production of composite materials, huntite/hydromagnesite minerals were ground to particle sizes of 10, 1, and 0.1 ,m. Phase and microstructural analysis of huntite/hydromagnesite mineral powders were undertaken using XRD and SEM-EDS preceding the fabrication of the composite materials. The ground minerals with different particle size and content levels were subsequently added to ethylene vinyl acetate copolymer to produce composite materials. After fabrication of huntite/hydromagnesite reinforced plastic composite samples, they were characterized using DTA-TG, FTIR, and SEM-EDS. Flame retardancy tests were undertaken as a main objective of this research. The size distribution and the mineral content effects are measured regarding the flame retardancy of the polymer composites It was concluded that the flame retardant properties of plastic composites were improved as the mineral content increased and the size was reduced. POLYM. COMPOS., 31:1692,1700, 2010. © 2010 Society of Plastics Engineers. [source] Flame retardancy and toughening of high impact polystyrenePOLYMER COMPOSITES, Issue 4 2007Wenguang Cui Flame retardant high impact polystyrene (HIPS) was prepared by melt blending HIPS, nano-modified aluminum trihydrate (nano-CG-ATH), red phosphorus masterbatch (RPM), and modified polyphenylene oxide (MPPO). Styrene-butadiene-styrene (SBS) was used as a toughener in this research. The effects of nano-CG-ATH, RPM, MPPO, and SBS on properties of HIPS composites were studied by combustion test, mechanical tests, and thermogravimetric analysis. The morphologies of fracture surfaces and char layers were characterized through scanning electron microscopy (SEM). The HIPS/nano-CG-ATH/RPM/MPPO (60/6/9/25) composite and its combustion residues at various temperatures were characterized by Fourier transform infrared (FTIR) spectra analysis. The results showed that the UL-94 rating of the HIPS/nano-CG-ATH/RPM/MPPO (60/6/9/25) composite reached V-0 and its char layer after flame test was integrated, but its impact strength was low. Addition of SBS improved its impact property and did not influence its thermal and flame retardant properties but lowered its tensile strength and flexural modulus to some extent. The FTIR spectra confirmed that the POC group was present in the charred substance. POLYM. COMPOS., 28:551,559, 2007. © 2007 Society of Plastics Engineers [source] Screening flame retardants for plastics using microscale combustion calorimetry,POLYMER ENGINEERING & SCIENCE, Issue 10 2007Richard E. Lyon Microscale combustion calorimetry (MCC) was evaluated as a screening test for efficacy of flame-retardant additives in polymers. The MCC method separately reproduces the gas and condensed phase processes of flaming combustion in a nonflaming laboratory test and forces them to completion to obtain intrinsic/material combustion properties. At flame extinction, these MCC combustion properties are comparable in magnitude and effect to the extrinsic factors (sample size and orientation), physical behavior (dripping, swelling), and chemical processes (flame inhibition, charring) associated with flame retardancy. Consequently, MCC properties by themselves cannot correlate flame resistance of plastics over a broad range of flame-retardant chemical composition. POLYM. ENG. SCI., 47:1501,1510, 2007. © 2007 Society of Plastics Engineers [source] Flame retarding effects of nanoclay on wood,fiber compositesPOLYMER ENGINEERING & SCIENCE, Issue 3 2007G. Guo This research article focuses on investigating the effects of nanoclay particles on the flame retarding characteristics of wood,fiber/plastic composites (WPC) using ASTM D635. The processing aspects of nanocomposites with WPC are presented. The processing techniques for controlling the degree of exfoliation and the cost aspect are also described. It turns out that the coupling agent used for wood,fibers is also effective for the exfoliation of clay, and therefore, no additional cost is required. This research indicates that the structure of nanocomposites (i.e., the degree of exfoliation) and the clay content used have a large impact on the flame retardancy of WPC. The flame retardancy is investigated as a function of these parameters. Based on this, a cost-effective way to improve flame retardancy of WPC is presented. POLYM. ENG. SCI., 47:308,313, 2007. © 2007 Society of Plastics Engineers. [source] Crown ether-modified clays and their polystyrene nanocompositesPOLYMER ENGINEERING & SCIENCE, Issue 9 2002Hongyang Yao Crown ether-modified clays were obtained by the combination of sodium and potassium clays with crown ethers and cryptands. Polystyrene nanocomposites were prepared by bulk polymerization in the presence of these clays. The structures of nanocomposites were characterized by X-ray diffraction and transmission electron microscopy. Their thermal stability and flame retardancy were measured by thermogravimetric analysis and cone calorimetry, respectively. Nanocomposites can be formed only from the potassium clays; apparently the sodium clays are not sufficiently organophilic to enable nanocomposite formation. The onset temperature of the degradation is higher for the nanocomposites compared to virgin polystyrene, and the peak heat release rate is decreased by 25% to 30%. [source] Thermal behavior and flame retardancy of flexible poly(vinyl chloride) treated with Al(OH)3 and ZnOPOLYMER INTERNATIONAL, Issue 11 2005Hongqiang Qu Abstract Al(OH)3 as flame retardant and smoke suppressant for flexible poly(vinyl chloride) was evaluated alone and with ZnO, using thermal analytical techniques, limiting oxygen index and smoke density rating tests. The thermal behavior and flammability of the samples treated with Al(OH)3 and ZnO were studied by differential thermal analysis and thermogravimetric analysis. The activation energy was calculated by using the Vyazovkin model-free kinetic and Kissinger methods. The results showed that the flame-retardant and smoke-suppressant properties of the samples treated with Al(OH)3 and ZnO were related to the content of ZnO and the thermal effect during the process of thermal degradation of the samples. Copyright © 2005 Society of Chemical Industry [source] | ||||||||||