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Calorimeter
Kinds of Calorimeter Terms modified by Calorimeter Selected AbstractsOptimization of cure kinetics parameter estimation for structural reaction injection molding/resin transfer moldingPOLYMER COMPOSITES, Issue 6 2001Robert J. Duh A numerical method is proposed for polymer kinetic parameter estimation of either Structural Reaction Injection Molding (SRIM) or Resin Transfer Molding (RTM). The method simulates either radial flow or axial flow of reactive resins through a fiber preform inside a mold cavity. This method considers a non-isothermal environment with different inlet boundary conditions. Based on the molding conditions, this method can find the best values of chemical kinetic parameters by comparing the simulated temperature history and the experimental temperature history. Since the kinetic parameters are estimated with the real molding conditions, the simulations using these parameter values can have better agreement with molding data than those parameters which are obtained from idealized conditions such as Differential Scanning Calorimeter (DSC). The optimization approach was verified by estimating kinetics parameters for RTM data available in the literature. Temperatures predicted by the optimized kinetics parameters are compared with experimental data for two different molding conditions: injection of a thermally activated resin into a radial mold under constant pressure flow, and injection of a mix activated resin into a radial mold under constant volume. In both cases, the optimized kinetics parameters fit the temperature data well. [source] Measurements of the thermal conductivity and thermal diffusivity of polymersPOLYMER ENGINEERING & SCIENCE, Issue 11 2003Xing Zhang In this paper, the thermal conductivity and thermal diffusivity of nine polymers were measured by using the transient short-hot-wire method. The corresponding specific heat was measured with a commercial Differential Scanning Calorimeter (DSC). The effects of temperature on the thermal conductivity, thermal diffusivity, and the product of density and specific heat are further discussed. The results show that the transient short-hot-wire method can be used to measure the thermal conductivity, thermal diffusivity, and the product of density and specific heat of polymers within uncertainties of 3%, 6%, and 9%, respectively. [source] Novel Synthesis of , -FeOOH Nanofluid and Determination of Its Heat Capacity by an Adiabatic CalorimeterCHINESE JOURNAL OF CHEMISTRY, Issue 7 2009Zhaodong NAN Abstract A novel and facile method for preparation of stable nanofluid is introduced, in which FeCl3·6H2O and urea were used as reactants without any surfactants. The obtained solid sample was proved to be , -FeOOH by XRD technology and spindle-shaped by TEM technology. The coexisting NH3 molecules may be the main reason for the stable nanofluid. The weak bonding between nitrogen and iron atoms would be formed. The investigation on the excess heat capacity of the obtained nanofluid sustains this opinion. The heat capacities of the obtained , -FeOOH particles and the nanofluid were determined by an adiabatic calorimeter. And these obtained results will help the applications of , -FeOOH and the nanofluid to industry, and the establishment of the model of thermal conductivity of nanofluid. The thermodynamic properties of the obtained , -FeOOH particles and the nanofluid were calculated based on the obtained functions of heat capacity with respective to thermodynamic temperature and the relationships between the thermodynamic properties. [source] Spectroscopic and crystal structure analysis of diamminebis(2,4,6-triiodophenolato-O) copper(II)CRYSTAL RESEARCH AND TECHNOLOGY, Issue 5 2006Gülsün Göka Abstract The crystal structure of [Cu(C6H2I3O)2(NH3)2] (CCDC 238896) has been determined by x-ray diffraction. This monomeric centrosymmetric Cu(II) complex crystallizes in the monoclinic system. The CuO2N2 coordination sphere is trans -planar, [Cu,O: 1.943(5) Å and Cu-N: 1.972(7)] with the fifth and sixth coordination sites occupied by I atoms from the phenoxide ions [Cu,I1: 3.3552(8) Å] to form a tetragonally elongated octahedral structure for CuO2N2I2 coordination. The complex molecules hold together in a one dimensional chain true [100] direction by intermolecular hydrogen bonds. Differantial scanning calorimeter, FTIR and magnetic susceptibility measurements were also performed in order to identify the title complex. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Metabolic Heat Production, Heat Loss and the Circadian Rhythm of Body Temperature in the RatEXPERIMENTAL PHYSIOLOGY, Issue 3 2003Roberto Refinetti Metabolic heat production (calculated from oxygen consumption), dry heat loss (measured in a calorimeter) and body temperature (measured by telemetry) were recorded simultaneously at 6 min intervals over five consecutive days in rats maintained in constant darkness. Robust circadian rhythmicity (confirmed by chi square periodogram analysis) was observed in all three variables. The rhythm of heat production was phase-advanced by about half an hour in relation to the body temperature rhythm, whereas the rhythm of heat loss was phase-delayed by about half an hour. The balance of heat production and heat loss exhibited a daily oscillation 180 deg out of phase with the oscillation in body temperature. Computations indicated that the amount of heat associated with the generation of the body temperature rhythm (1.6 kJ) corresponds to less than 1% of the total daily energy budget (172 kJ) in this species. Because of the small magnitude of the fraction of heat balance associated with the body temperature rhythm, it is likely that the daily oscillation in heat balance has a very slow effect on body temperature, thus accounting for the 180 deg phase difference between the rhythms of heat balance and body temperature. [source] Fire hazard evaluation of thermoplastics based on analytic hierarchy process (AHP) methodFIRE AND MATERIALS, Issue 5 2010Baogang Yu Abstract Combustibility performance of 14 compositions including five main thermoplastics (polycarbonate (PC), polypropylene (PP), high impact polystyrene (HIPS), acrylonitrile butadiene styrene (ABS) and poly (vinyl chloride) (PVC)) was tested by cone calorimeter. The fire growth index, total heat release amount index, total smoke release amount index and toxicity product index were calculated, based on which an index system for evaluating fire hazard was set up. All factors in this index system had been analyzed by the analytic hierarchy process, and the specific weight for each factor had been determined. Then fire hazard of thermoplastics was evaluated considering integrated fire hazard index. The results show that fire hazards of HIPS-phosphate fire retardant (PFR), PVC-non-flame retardant, ABS-brominated flame retardant (BFR) and PC/ABS-PFR are higher than PC-BFR and PP-non-halogenated flame retardant. Copyright © 2009 John Wiley & Sons, Ltd. [source] Fire performance of wood (Pinus radiata) treated with fire retardants and a wood preservativeFIRE AND MATERIALS, Issue 6 2008D. C. O. Marney Abstract In this work, we co-formulated an oil-borne copper naphthenate/permethrin wood preservative system with synthetic polymer-based fire-retardant additives prior to the impregnation of Pinus radiata sapwood. We evaluated what effect, if any, the preservative had upon the fire performance properties of the fire retardants and whether the fire retardants impacted on the fungicidal and termiticidal efficacy of the preservative. The fire retardants included halogenated and phosphorus-based systems. A mass loss calorimeter, in conjunction with a thermopile, was used to measure the time to ignition and the peak heat release rate (PHRR) from which the fire performance index (FPI) was determined. The preservative properties were evaluated using termite and soil-block decay bioassays. In summary, we found that the rate of fire growth was reduced when the fire retardants were used in combination with the wood preservative. We also found that the PHRR was a better determinant of fire performance than the FPI. The performance of the wood preservative was enhanced against fungal decay and termite attack when used in combination with the fire retardants. The fire retardants also demonstrated some wood preservative properties of their own. Copyright © 2008 John Wiley & Sons, Ltd. [source] Development of fire-retarded materials,Interpretation of cone calorimeter dataFIRE AND MATERIALS, Issue 5 2007B. Schartel Abstract There is little consensus within the fire science community on interpretation of cone calorimeter data, but there is a significant need to screen new flammability modified materials using the cone calorimeter. This article is the result of several discussions aiming to provide guidance in the use and interpretation of cone calorimetry for those directly involved with such measurements. This guidance is essentially empirical, and is not intended to replace the comprehensive scientific studies that already exist. The guidance discusses the fire scenario with respect to applied heat flux, length scale, temperature, ventilation, anaerobic pyrolysis and set-up represented by the cone calorimeter. The fire properties measured in the cone calorimeter are discussed, including heat release rate and its peak, the mass loss and char yield, effective heat of combustion and combustion efficiency, time to ignition and CO and smoke production together with deduced quantities such as FIGRA and MARHE. Special comments are made on the use of the cone calorimeter relating to sample thickness, textiles, foams and intumescent materials, and the distance of the cone heater from the sample surface. Finally, the relationship between cone calorimetry data and other tests is discussed. Copyright © 2007 John Wiley & Sons, Ltd. [source] Cone calorimeter analysis of UL-94 V-rated plastics,FIRE AND MATERIALS, Issue 4 2007Alexander B. Morgan Abstract Cone calorimeter analysis was conducted on 18 thermoplastics with different UL-94 vertical burn test (V) ratings. Ratings varied from V-0 to no rating (NR), and the types of thermoplastics included were polycarbonate (PC), acrylonitrile,butadiene,styrene (ABS), PC/ABS blends, high-impact polystyrene (HIPS), polypropylene (PP), and poly(vinyl chloride) (PVC). Our analysis of the cone calorimeter data found that there were correlations between UL-94 V rating and some cone calorimeter measurements (peak heat release rate (HRR) average and HRR at 60 s) and no relationship for other measurements (time to ignition and total heat release). However, no precise correlation was found due to significant differences in flame retardant mechanism and polymer fuel energy values. In this paper, we seek to explain further why a broad quantitative relationship between UL-94 V and cone calorimeter remains elusive, and also to show how the cone calorimeter can be used to understand why a material passes or fails a particular UL-94 V rating. Copyright © 2006 John Wiley & Sons, Ltd. [source] Assessing the performance of intumescent coatings using bench-scaled cone calorimeter and finite difference simulationsFIRE AND MATERIALS, Issue 3 2007M. Bartholmai Abstract A method was developed to assess the heat insulation performance of intumescent coatings. The method consists of temperature measurements using the bench-scaled experimental set-up of a cone calorimeter and finite difference simulation to calculate the effective thermal conductivity dependent on time/temperature. This simulation procedure was also adapted to the small scale test furnace, in which the standard time,temperature curve is applied to a larger sample and thus which provides results relevant for approval. Investigations on temperature and calculated effective thermal conduction were performed on intumescent coatings in both experimental set-ups using various coating thicknesses. The results correspond to each other as well as showing the limits of transferability between both fire tests. It is shown that bench-scaled cone calorimeter tests are a valuable tool for assessing and predicting the performance of intumescent coatings in larger tests relevant for approval. The correlation fails for processes at surface temperatures above 750°C, which are not reached in the cone calorimeter, but are attained in the small scale furnace set-up. Copyright © 2006 John Wiley & Sons, Ltd. [source] Flammability studies of sodium thiosulphate or metabisulphite impregnated wood using cone calorimeterFIRE AND MATERIALS, Issue 2 2007imkovic Abstract Spruce wood boards impregnated with Na2S2O3 or Na2S2O5 were studied with the cone calorimeter. The presence of Na2S2O3 lowered the average heat release rate in comparison to untreated material. The total amounts of CO and CO2 production were reduced by the treatment and also the specific extinction area and mass loss rate decreased. Washing of the salt from the material with water caused partial loss of the properties. Addition of the second impregnation step using acids (HCOOH, H3BO3 or H3PO4) resulted in the fixation of the sulphur in wood, but gave not the results of single-step modification for thiosulphate. With Na2S2O5 and without acid, the CO and time-to-ignition values were higher and average heat release rate smaller in comparison to unmodified material. Combined one step Na2S2O5/H3BO3 treatment lowered the CO, CO2 and specific extinction area values in comparison to the modification with Na2S2O5, similarly like it was observed for Na2S2O3/H3BO3 two-step-treatment. According to time-to-ignition values, Na2S2O5 alone at 5% addition is a better flame retardant than Na2S2O3 at 7%, but the effect is diminished at 10% amount or presence of acids. The total smoke release curves showed decrease due to modification in both phases of the process. Introduction of water washing as well as the acid treatment further lowered the values. The best results were achieved with 15% Na2S2O3,2% H3PO4,H2O system. According to the total smoke release curve the specimen produced more than five times smaller amount of smoke than untreated material in the first phase of the process. It seams that the concentration of Na2S2O5 is less affecting the properties than the synergistic effect of the Na2S2O3 or Na2S2O5/H3BO3 system. Although the level of smoke is low, the presence of elemental sulphur causes smaller times-to-ignition than on starting material. Copyright © 2006 John Wiley & Sons, Ltd. [source] Fire calorimetry relying on the use of the fire propagation apparatus.FIRE AND MATERIALS, Issue 2 2006Part I: early learning from use in Europe Abstract The fire propagation apparatus (FPA) is the bench scale fire calorimeter that was recently described in its updated version in ASTM E 2058. The apparatus was originally developed in the USA by Tewarson and co-workers from the mid 1970s, under the name ,50 kW lab-scale flammability apparatus', and is therefore still known in Europe as the ,Tewarson apparatus'. The paper focuses on the experience achieved so far with the first modern version of the apparatus implemented in Europe (France). Part I in this series of articles reports on the main results achieved during the commissioning period of the apparatus. In a first step, preliminary experiments were carried out in order to check and calibrate different sub-equipment of the calorimeter. The results are principally presented for the load cell system and the infrared heating system which are essential pieces of sub-equipment. In a second step, a set of fire tests using methane or acetone as fuel was carried out in order to check and calibrate the overall working of the calorimeter in well-fire conditions. The performance of the calorimeter was also checked when it operates in under-ventilated fires. Relevant testing procedures and potential technical problems are discussed. A set of recommendations are derived from the early learning obtained at the INERIS fire laboratory in order to check the consistency of the results obtained from bench-scale fire tests. These recommendations are thought to be applicable to all types of bench scale fire calorimeters. Copyright © 2005 John Wiley & Sons, Ltd. [source] A flammability performance comparison between synthetic and natural clays in polystyrene nanocompositesFIRE AND MATERIALS, Issue 4 2005Alexander B. Morgan Abstract Polymer-clay nanocomposites are a newer class of flame retardant materials of interest due to their balance of mechanical, thermal and flammability properties. Much more work has been done with natural clays than with synthetic clays for nanocomposite flammability applications. There are advantages and disadvantages to both natural and synthetic clay use in a nanocomposite, and some of these, both fundamental and practical, will be discussed in this paper. To compare natural and synthetic clays in regards to polymer flammability, two clays were used. The natural clay was a US mined and refined montmorillonite, while the synthetic clay was a fluorinated synthetic mica. These two clays were used as inorganic clays for control experiments in polystyrene, and then converted into an organoclay by ion exchange with an alkyl ammonium salt. The organoclays were used to synthesize polystyrene nanocomposites by melt compounding. Each of the formulations was analysed by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). Flammability performance was measured by cone calorimeter. The data from the experiments show that the synthetic clay does slightly better at reducing the heat release rate (HRR) than the natural clay. However, all the samples, including the inorganic clay polystyrene microcomposites, showed a decreased time to ignition, with the actual nanocomposites showing the most marked decrease. The reason for this is postulated to be related to the thermal instability of the organoclay (via the quaternary alkyl ammonium). An additional experiment using a more thermally stable organoclay showed a time to ignition identical to that of the base polymer. Finally, it was shown that while polymer-clay nanocomposites (either synthetic or natural clay based) greatly reduce the HRR of a material, making it more fire safe, they do not provide ignition resistance by themselves, at least, at practical loadings. Specifically, the cone calorimeter HRR curve data appear to support that these nanocomposites continue to burn once ignited, rather than self-extinguish. Copyright © 2004 John Wiley & Sons, Ltd. [source] Surface temperature measurements on burning materials using an infrared pyrometer: accounting for emissivity and reflection of external radiationFIRE AND MATERIALS, Issue 1 2004Joe Urbas Abstract This paper demonstrates the successful use of an infrared pyrometer, operating in the 8,10 µm wavelength band, to measure the surface temperature of combustible specimens in a heat release calorimeter. The temperature histories of ten different materials were measured in the ICAL (intermediate scale calorimeter). The set of materials comprised four wood products, gypsum board, polyisocyanurate foam, PVC floor tile, PMMA and two non-combustible boards. A small-diameter bare thermocouple was installed on each specimen in order to determine an accurate temperature for comparison. The spectral emissivity and the spectral flux reflected from the surface were measured simultaneously and used to correct the apparent temperature measured by the pyrometer. The spectral emissivity and reflected spectral flux were both constant prior to ignition for all the combustible materials. During the burning phase all the combustible materials had a spectral emissivity very close to unity. The agreement between the temperatures measured with the pyrometer and thermocouple was not affected by the flame. The wood products, the polyisocyanurate foam and the calcium silicate board required no correction for reflected spectral flux over the whole temperature range. Copyright © 2004 John Wiley & Sons, Ltd. [source] Isocyanates, aminoisocyanates and amines from fires,a screening of common materials found in buildingsFIRE AND MATERIALS, Issue 6 2003Per Blomqvist Abstract Isocyanates, aminoisocyanates and amines were quantified from the combustion of 24 different materials or products typically found in buildings. Small-scale combustion experiments were conducted in the cone calorimeter, where generally well-ventilated combustion conditions are attained. Measurements were further made in two different full-scale experiments. Isocyanates and amino-compounds were sampled using an impinger-filter sampling system with a reagent solution of di-n-butylamine in toluene. Filter and impinger solution were analysed separately using LC-MS technique. Further the particulate distribution in the smoke gases was determined by impactor technique, and selected gaseous compounds quantified by FTIR. It was found in the small-scale that isocyanates were produced from the majority of the materials tested. The highest concentration was found for glass wool insulation, and further high concentrations were found for PUR products, particleboard, nitrile rubber and melamine. Lower concentrations were found for wood and cable-products. Amino-isocyanates and amines were generally found from PUR products only. The distribution of isocyanates between the particulate- and fluid phases varied for the different materials and a tendency to enrichment of particles was seen for some of the materials. Further, when comparing the potential health hazard between isocyanates and other major fire gases (based on NIOSH IDLH-values) it was found that isocyanates in several cases represented the greatest hazard. Copyright © 2003 John Wiley & Sons, Ltd. [source] Particles from fires,a screening of common materials found in buildingsFIRE AND MATERIALS, Issue 6 2003Tommy Hertzberg Abstract Small combustion generated particles are known to have a negative impact on human health and on the environment. In spite of the huge amount of particles generated locally in a fire accident, few investigations have been made on the particles from such fires. In this article, 24 different materials or products, typically found in buildings have been exposed to burning conditions in order to examine their particle generating capacity. In addition, a carbon fibre based composite material was tested in order to investigate if asbestos-resembling particles could be generated in a fire situation. The majority of the experiments were performed in the small-scale cone calorimeter, and some further data were collected in intermediate scale (SBI) and full scale (room-corner) tests. Additional testing of the composite material was made in a small-scale tubular reactor. The amount of particles and particle size distributions were measured by the use of a low-pressure impactor and particle aerodynamic diameter sizes from 30 nm to 10 ,m were measured. The results from the project show that the yield of particles generated varied significantly between materials but that the shape of mass and number size distributions were very similar for all the materials tested. The maximum amount of particles was obtained from materials that did not burn well (e.g. flame retarded materials). Well-burning materials, e.g. wood materials, tend to oxidize all available substances and thereby minimize the amount of particles in the smoke gas. It was found that asbestos-resembling particles could be produced from under-ventilated combustion of the composite material tested. Copyright © 2003 John Wiley & Sons, Ltd. [source] Heat resistance and flammability of high performance fibres: A reviewFIRE AND MATERIALS, Issue 4-5 2002Serge Bourbigot The heat and flame resistance of high performance fibres are reviewed according to the literature data. The performance is discussed considering the physical and chemical structure of the fibres. Some selected high performance fibres are then evaluated using the cone calorimeter as a fire model to provide realistic data on the fire behaviour of the fibres. They are also examined in terms of heat resistance using combined TGA/DSC. The results are discussed and compared with literature data. Heterocyclic rigid-rod polymers (poly (p-phenylene-2,6-benzobisoxazole or PBO (Zylon®) and poly(2,6-diimidazo (4,5-b:4,,5,-e) pyridinylene-1,4 (2,5-dihydroxy) phenylene or PIPD (M5)) exhibit the best performance (little or contribution to fire, low smoke and good heat resistance) and offer a good combination between heat and flame resistance and mechanical properties. Copyright © 2002 John Wiley & Sons, Ltd. [source] BDMC interlaboratory cone calorimeter test programmeFIRE AND MATERIALS, Issue 1 2002Joe Urbas In the spring of 1997, seven companies and industry associations from the USA and Canada decided to sponsor the cone calorimeter interlaboratory test programme. Reproducibility and repeatability were determined for the scalar variables measured in the cone calorimeter (ASTM E1354) according to the protocol developed by the Board for the Coordination of the Model Codes. The main requirement of the protocol was that the sample irradiance should be 75 kW/m2. The purpose of the project was to assist the model building code organizations, NFPA and various other groups in the development of a system to determine degrees of combustibility of building materials. Three US and one Canadian laboratory agreed to conduct tests on 16 materials. The results of this round robin show that the cone calorimeter, following the Board for the Coordination of the Model Codes protocol, can provide precision similar to that cited in the current cone calorimeter standards. It is recommended that further improvements of the standards are pursued and provisions are made to improve the quality of operation of the cone calorimeter in commercial laboratories to maintain and possibly improve its repeatability and reproducibility. Copyright © 2002 John Wiley & Sons, Ltd. [source] Note: measuring the effective heats of combustion of transformer-insulating fluids using a controlled-atmosphere cone calorimeterFIRE AND MATERIALS, Issue 1 2002Fu-Yu Hshieh The effective heats of combustion of two commonly used transformer-insulating fluids, a high molecular weight hydrocarbon fluid and a 50 cS silicone fluid, have been measured using a controlled-atmosphere cone calorimeter. The study shows that the cone calorimeter is a good tool to measure the effective heats of combustion of transformer-insulating fluids. 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] Time to ignition, heat release rate and fire endurance time of wood in cone calorimeter testFIRE AND MATERIALS, Issue 4 2001Toshiro HaradaArticle first published online: 15 MAR 200 The combustibility of wood specimens was tested by cone calorimeter. A total of nine wood species (four softwood and five hardwood) were used. The thicknesses of the specimens were 10, 20 and 40 mm. The heated surfaces were radial, tangential, and cross-sections of wood. The irradiance levels were 20, 25, 30, 40 and 50 kWm,2. The effects of wood species, density, specimen thickness, heated surface (radial, tangential or cross-section), and irradiance level on time to ignition, mass loss rate, heat release rate and fire endurance time were studied. Simple formulae were proposed to forecast those indices and their validity was examined. Copyright © 2002 John Wiley & Sons, Ltd. [source] Resting energy expenditure and body composition of Labrador Retrievers fed high fat and low fat dietsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5-6 2006S. Yoo Summary A high dietary fat intake may be an important environmental factor leading to obesity in some animals. The mechanism could be either an increase in caloric intake and/or a decrease in energy expenditure. To test the hypothesis that high fat diets result in decreased resting energy expenditure (REE), we measured REE using indirect calorimetry in 10-adult intact male Labrador Retrievers, eating weight-maintenance high-fat (HF, 41% energy, average daily intake: 8018 ± 1247 kJ/day, mean ± SD) and low-fat (LF, 14% energy, average daily intake: 7331 ± 771 kJ/day) diets for a 30-day period. At the end of each dietary treatment, body composition measurements were performed using dual-energy X-ray absorptiometry. The mean ± SD REE was not different between diets (4940 ± 361 vs. 4861 ± 413 kJ/day on HF and LF diets respectively). Measurements of fat-free mass (FFM) and fat mass (FM) also did not differ between diets (FFM: 26.8 ± 2.3 kg vs. 26.3 ± 2.5 kg; FM: 3.0 ± 2.3 vs. 3.1 ± 1.5 kg on HF and LF diets respectively). In summary, using a whole body calorimeter, we found no evidence of a decrease in REE or a change in body composition on a HF diet compared with LF diet. [source] Metallic oxides as fire retardants and smoke suppressants in flexible poly(vinyl chloride)JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Antonio Rodolfo Jr. Abstract Combustion and smoke emission properties of PVC compounds, modified with copper (II), molybdenum, and zinc oxides, were studied using cone calorimeter, limiting oxygen index (LOI) and thermogravimetry coupled with mass spectrometry (TG/MS). Results showed that the metal oxides have a very significant effect on the combustion and smoke suppression properties of the PVC compounds. The results also confirmed the anticipation mechanisms of the dehydrochlorination reactions, reductive coupling, and elimination of benzene resulting from the presence of copper (II), molybdenum, and zinc, indicated by the increasing content of postcombustion char residue and the significant reduction in benzene production, indicated by the MS measurements performed. The results also provide indications that the combination of the copper (II) and molybdenum oxides is the one with the best balance of combustion properties, as it reduced the heat released and promoted the suppression of smoke more efficiently. The formulations containing ZnO, because of their strong Lewis acid character, indicated a less pronounced reduction of smoke released during the combustion process, when compared with copper (II) and molybdenum oxides. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Flammability and mechanical properties of Al(OH)3 and BaSO4 filled polypropyleneJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010S. Tan Abstract The flammability and mechanical properties of Al(OH)3/BaSO4/polypropylene (PP) composites were investigated. The flow, morphological, and thermal properties were also analyzed by melt flow index (MFI), Scanning electron microscopy (SEM), and Differential scanning calorimeter (DSC) studies, respectively. Total filler amount was fixed at 30 wt % to optimize physical characteristics of the composites. In addition to the flame retardant filler Al(OH)3, BaSO4 was used to balance the reduction in impact strength at high filler loadings. Substantial improvement in mechanical properties was achieved for 20 wt % Al(OH)3 (i.e., 10 wt % BaSO4) composition while maximum flammability resistance was obtained for 30 wt % Al(OH)3 composite. SEM studies showed that the presence of aggregated Al(OH)3 particles led to low interfacial adhesion between them and PP matrix ending up with decreased mechanical strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Polypropylene nanocomposite film: A critical evaluation on the effect of nanoclay on the mechanical, thermal, and morphological behaviorJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010S. K. Sharma Abstract Polypropylene (PP)/clay nanocomposites prepared by melt blending technique using different percentages of clay with and without maleic anhydride grafted PP (MA-PP) were studied. The intercalated and exfoliated structure of nanocomposites was characterized by X-Ray Diffraction (XRD) and transmission electron microscopy (TEM). Because of the typical intercalated and exfoliated structure, the tensile modulus of the nanocomposites were improved significantly as compared to virgin PP. The viscoelastic behavior of the nanocomposites was studied by dynamical mechanical analysis (DMA) and the results showed that with the addition of treated clay to PP there was substantial improvement in storage modulus increases. The thermal stability and crystallization of the PP nanocomposites as studied by differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA) were also improved significantly compared to PP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Accelerator adsorption onto carbon nanotubes surface affects the vulcanization process of styrene,butadiene rubber compositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2009A. De Falco Abstract The multiwalled carbon nanotubes (MWCNT) filled styrene,butadiene rubber (SBR) composites were prepared by incorporating MWCNT in a SBR/toluene solution and subsequently evaporating the solvent. These composites have shown a significant improvement in Young's modulus and tensile strength with respect to SBR gum without sacrificing high elongation at break. However, this improvement is less than expected at the higher filler content. Then, the influence of low concentrations of MWCNT on the vulcanization process of the SBR composites was studied by means of rheometer torque curves, swelling measurements, differential scanning calorimeter (DSC) analysis, and Fourier transform infrared (FTIR) spectroscopy. Also, their thermal degradation was studied by thermogravimetric analysis (TGA). It has been noticed that MWCNT affects the cure kinetics of SBR gum matrix reducing all parameters, i.e., the total heat rate and order of the reaction, scorch delay, maximum torque, and crosslink density. This effect increases as MWCNT content does, and it was attributed to the adsorption of the accelerator employed in the vulcanization (N -tert-butyl-benzothiazole-2-sulfenamide) onto the MWCNT surface. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Crystalline morphology and dynamical crystallization of antibacterial ,-polypropylene compositeJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008Xin Chen Abstract The crystalline morphology and dynamical crystallization of antibacterial polypropylene composite and pure polypropylene were investigated via differential scanning calorimeter (DSC), wide angle X-ray diffraction (WAXD), and real-time hot-stage optical microscopy (OM). The results reveal that the crystalline morphology of antibacterial PP composites changes with variations of the crystallization conditions and compositions. The crystalline phase consists of both ,-PP and ,-PP crystals. The content of ,-PP decreases with the increase in antibacterial agent content and cooling rate. With the addition of ,-nucleating agent, the morphologies of all dynamically crystallized antibacterial PP composites show no obvious spherulitic morphology, and the decrease of crystal perfection and the increase of nucleation density of antibacterial PP composite system could be observed. With the increase of antibacterial agent content, the overall crystallization rates of the antibacterial PP composite increase dramatically, while the content of ,-PP in all antibacterial PP composite decrease distinctly under given cooling conditions. These results can be explained by the interruptive effect of antibacterial agent on interactions of ,-nucleating agent components and the obstructing effect of antibacterial agent on the mobility of PP chains in melts. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Properties of styrene-methyl methacrylate grafted DPNR latex at different monomer concentrationsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Siti Hajjar Che Man Abstract The graft copolymerization of styrene and methyl methacrylate (MMA) on to deproteinized natural rubber (DPNR) latex was carried out. The effect of monomer concentrations on grafting efficiency, thermal and mechanical properties was studied. The synthesized graft copolymers were characterized by proton nuclear magnetic resonance (1H NMR) and the highest grafting efficiency was found at 20 wt % monomer concentration. At low monomer concentration (10 wt %) the grafting was not significant and at 30 wt %, the grafting efficiency was slightly decreased. The thermal properties of graft copolymers were analyzed using differential scanning calorimeter (DSC) and thermal gravimetric analysis (TGA). The degradation temperature (Tdeg) of the graft copolymer was increased with the increase in monomer concentration which indicates the improvement in thermal stability. The DSC result showed improvement in miscibility between the components as the monomer concentration increased. The mechanical properties of gum and filled modified NR were also investigated in terms of tensile strength, tensile modulus and elongation at break. The tensile strength and elongation at break decreased with an increase in monomer concentration while tensile modulus increased as the monomer concentration increased. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Synthesis, characterization, and electrical properties of diazophenylene bridged Co, Ni, Cu, Ce, and Er phthalocyanine polymersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Cemil Alkan Abstract In this research, diazophenylene bridged metal-phthalocyanine (Pc) polymers were produced from diazonium salt of 1,4-diaminophenylene and presynthesized 1,8,15,22-tetraamino metal-Pcs. 1,8,15,22-Tetraamino metal-Pc complexes of Co, Ni, Cu, Ce, and Er were obtained by reducing 1,8,15,22-tetranitro metal-Pc complexes synthesized from 3-nitrophthalic anhydride, urea, metal salt, and ammonium molybdate catalyst. Complexes and polymers were characterized by Fourier transform infrared (FTIR), ultraviolet,visible (UV,vis), and X-ray powder diffraction spectroscopes. X-ray analysis of the polymers showed that there were short-range orientations in the polymers. Thermal analysis of the complexes and the polymers were done by differential scanning calorimeter (DSC) and thermal gravimetric analysis (TGA) at a heating rate of 10°C min,1 under nitrogen atmosphere. Ash analysis was performed to determine the metal content of the polymers. Viscosimetry and ebullioscopy measurements of the soluble part of the polymers were done for molecular weight analysis of the soluble part in tetrahydrofuran (THF) at 25°C. Four-probe conductivity measurements on isothermal conditions revealed that the polymer samples showed 104 fold increases in their electrical conductivities when doped with iodine. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 [source] Microstructure dependent properties of polypropylene-clay nanocompositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Y. Fan Abstract The mechanical properties of melt processed polypropylene-montmorillonite nanocomposites were studied as a function of clay content. The measurement of tensile properties at room temperature and dynamic mechanical properties over a wide temperature range reveal a decrease in modulus and tensile strength of the composite with increasing clay content. The origins of this anomalous result were examined in detail using X-ray diffraction and differential scanning calorimeter, which averaged the microstructure over reasonable specimen volumes. Micromechanical models could be used to adequately describe the composite properties, provided appropriate properties for the matrix and particle were used. The matrix properties were found to affect the average properties significantly. © Wiley Periodicals, Inc. J Appl Polym Sci 103: 204,210, 2007 [source] | ||||||||||||||||||||||