The Experts below are selected from a list of 11178 Experts worldwide ranked by ideXlab platform
Miaojun Xu - One of the best experts on this subject based on the ideXlab platform.
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effect of a novel charring Foaming Agent on flame retardancy and thermal degradation of intumescent flame retardant polypropylene
Polymer Degradation and Stability, 2006Co-Authors: Bin Li, Miaojun XuAbstract:Abstract A new triazine polymer was synthesized by using cyanuric chloride, ethanolamine and ethylenediamine as raw materials. It is used both as a charring Agent and as a Foaming Agent in intumescent flame retardants, designated as charring–Foaming Agent (CFA). Effect of CFA on flame retardancy, thermal degradation and mechanical properties of intumescent flame retardant polypropylene (PP) system (IFR–PP system) has been investigated. The results demonstrated that the intumescent flame retardant (IFR) consisting of CFA, APP and Zeolite 4A is very effective in flame retardancy of PP. It was found that when the weight ratio of CFA to APP is 1:2, that is, the components of the IFR are 64 wt% APP, 32 wt% CFA and 4 wt% Zeolite 4A, the IFR presents the most effective flame retardancy in PP systems. LOI value of IFR–PP reaches 37.0, when the IFR loading is 25 wt% in PP. It was also found that when the IFR loading is only 18 wt% in PP, the flame retardancy of IFR–PP can still pass V-0 rating, and its LOI value reaches 30.2. TGA data obtained in pure nitrogen demonstrated that CFA has a good ability of char formation itself, and CFA shows a high initial temperature of the thermal degradation. The char residue of CFA can reach 35.7 wt% at 700 °C. APP could effectively promote the char formation of the APP–CFA system. The char residue reaches 39.7 wt% at 700 °C, while it is 19.5% based on calculation. The IFR can change the thermal degradation behaviour of PP, enhance T max of the decomposition peak of PP, and promote PP to form char, based upon the results of the calculation and the experiment. This is attributed to the fact that endothermic reactions took place in IFR charring process and the char layer formed by IFR prevented heat from transferring into inside of IFR–PP system. TGA results further explained the effective flame retardancy of the IFR containing CFA.
Bin Li - One of the best experts on this subject based on the ideXlab platform.
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effect of a novel charring Foaming Agent on flame retardancy and thermal degradation of intumescent flame retardant polypropylene
Polymer Degradation and Stability, 2006Co-Authors: Bin Li, Miaojun XuAbstract:Abstract A new triazine polymer was synthesized by using cyanuric chloride, ethanolamine and ethylenediamine as raw materials. It is used both as a charring Agent and as a Foaming Agent in intumescent flame retardants, designated as charring–Foaming Agent (CFA). Effect of CFA on flame retardancy, thermal degradation and mechanical properties of intumescent flame retardant polypropylene (PP) system (IFR–PP system) has been investigated. The results demonstrated that the intumescent flame retardant (IFR) consisting of CFA, APP and Zeolite 4A is very effective in flame retardancy of PP. It was found that when the weight ratio of CFA to APP is 1:2, that is, the components of the IFR are 64 wt% APP, 32 wt% CFA and 4 wt% Zeolite 4A, the IFR presents the most effective flame retardancy in PP systems. LOI value of IFR–PP reaches 37.0, when the IFR loading is 25 wt% in PP. It was also found that when the IFR loading is only 18 wt% in PP, the flame retardancy of IFR–PP can still pass V-0 rating, and its LOI value reaches 30.2. TGA data obtained in pure nitrogen demonstrated that CFA has a good ability of char formation itself, and CFA shows a high initial temperature of the thermal degradation. The char residue of CFA can reach 35.7 wt% at 700 °C. APP could effectively promote the char formation of the APP–CFA system. The char residue reaches 39.7 wt% at 700 °C, while it is 19.5% based on calculation. The IFR can change the thermal degradation behaviour of PP, enhance T max of the decomposition peak of PP, and promote PP to form char, based upon the results of the calculation and the experiment. This is attributed to the fact that endothermic reactions took place in IFR charring process and the char layer formed by IFR prevented heat from transferring into inside of IFR–PP system. TGA results further explained the effective flame retardancy of the IFR containing CFA.
Erich Wintermantel - One of the best experts on this subject based on the ideXlab platform.
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Water as Foaming Agent for open cell polyurethane structures
Journal of Materials Science: Materials in Medicine, 2004Co-Authors: H. Haugen, V. Ried, J. Will, M. Brunner, Erich WintermantelAbstract:The problem of moisture in polymer processing is known to any polymer engineer, as air bubbles may be formed. Hence granulates are generally dried prior to manufacturing. This study tried to develop a novel processing methods for scaffolds with controlled moisture content in thermoplastic polyurethane. The common Foaming Agents for polyurethane are organic solvents, whose residues remaining in the scaffold may be harmful to adherent cells, protein growth factors or nearby tissues. Water was used as a Foaming Agent and NaCl was used as porogens to achieve an open-cell structure. The polyether–polyurethane samples were processed in a heated press, and achieved a porosity of 64%. The pore size ranged between 50 and 500 μm. Human fibroblasts adhered and proliferate in the scaffold. A non-toxic production process was developed to manufacture a porous structure with a thermoplastic polyether–polyurethane. The process enables a mass-production of samples with adjustable pore size and porosity. In contrast to an existing method (solvent casting), the processing of the samples was not limited by its thickness. The process parameters, which attribute mostly to the pore building, were filling volume, temperature, NaCl-concentration and water-uptake rate.
Irene Cristina Magnabosco Mocellin - One of the best experts on this subject based on the ideXlab platform.
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carbonates as Foaming Agent in chip based aluminium foam precursor
Journal of Materials Science & Technology, 2010Co-Authors: Marco Haesche, Dirk Lehmhus, Jorg Weise, Manfred Wichmann, Irene Cristina Magnabosco MocellinAbstract:Replacement of TiH2 as Foaming Agent by CaCO3 (lime) and CaMg(CO3)2 (dolomite) for AlMg4.5- and AlSi9Cu3-foams was investigated considering influences on Foaming capability and cellular structure. Precursor materials were produced from alloy chip and powder mixtures by means of the thixocasting process. AlSi9Cu3 variants showed expansion levels sufficient for commercial use. Variations in expansion observed when CaCO3 and CaMg(CO3)2 were compared as Foaming Agent are explained based on the course of decomposition. Improved performance of dolomite-based foams relies on formation of stabilizing MgO phases, which do not develop during decomposition of CaCO3 in Al-Si-Cu alloys
H. Haugen - One of the best experts on this subject based on the ideXlab platform.
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Water as Foaming Agent for open cell polyurethane structures
Journal of Materials Science: Materials in Medicine, 2004Co-Authors: H. Haugen, V. Ried, J. Will, M. Brunner, Erich WintermantelAbstract:The problem of moisture in polymer processing is known to any polymer engineer, as air bubbles may be formed. Hence granulates are generally dried prior to manufacturing. This study tried to develop a novel processing methods for scaffolds with controlled moisture content in thermoplastic polyurethane. The common Foaming Agents for polyurethane are organic solvents, whose residues remaining in the scaffold may be harmful to adherent cells, protein growth factors or nearby tissues. Water was used as a Foaming Agent and NaCl was used as porogens to achieve an open-cell structure. The polyether–polyurethane samples were processed in a heated press, and achieved a porosity of 64%. The pore size ranged between 50 and 500 μm. Human fibroblasts adhered and proliferate in the scaffold. A non-toxic production process was developed to manufacture a porous structure with a thermoplastic polyether–polyurethane. The process enables a mass-production of samples with adjustable pore size and porosity. In contrast to an existing method (solvent casting), the processing of the samples was not limited by its thickness. The process parameters, which attribute mostly to the pore building, were filling volume, temperature, NaCl-concentration and water-uptake rate.