scholarly journals Zinc stearate from galvanizing waste materials and its use as thermal stabilizer in PVC industries

2016 ◽  
Vol 51 (4) ◽  
pp. 261-270
Author(s):  
FK Rony ◽  
SK Ray ◽  
A Hoque ◽  
M Asaduzzaman ◽  
S Sultana ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Product Yield ◽  
Zinc Stearate ◽  
Waste Materials ◽  
Precipitation Method ◽  
Thermal Stabilizer ◽  
Thermo Gravimetric Analyzer ◽  
Lead Zinc ◽  
Zinc Dross ◽  
Thermal Stability Of

Galvanizing industries of Bangladesh produce profuse amount of environmentally hazardous solid waste materials like zinc dross which contains significant amount of valuable zinc and harmful heavy lead. Zinc was extracted as zinc chloride (ZnCl2) from zinc dross. Zinc stearate (ZnSt2) samples were prepared by precipitation method from stearic acid, sodium hydroxide and ZnCl2 by varying the amount of the reagents and product yield found within the range 96.06-99.18%. Characteristic peaks of ZnSt2 were investigated by Fourier Transform Infrared Spectroscopy (FTIR). Differential Scanning Calorimeter (DSC) onset curve assigned accurate melting point within the range 122.84-124.03°C. Surface morphology of ZnSt2 was observed by Scanning Electron Microscope (SEM) and products had semi-crystalline structure. Thermal stability of ZnSt2 was evaluated by Thermo-gravimetric Analyzer (TGA) that complied with literature. A combination of ZnSt2 and Calcium stearate (CaSt2) at 1:1 ratio was used as thermal stabilizer in the powder commercial grade PVC resin and performed better thermal stability. The dehydrochlorination temperature of PVC with mixed stearates was 344.67±1.04°C for 10% (w/w) loading whereas for PVC, PVC with 10% (w/w) ZnSt2 and PVC with 10% (w/w) CaSt2, it was 269.83±1.04°C, 317.33±1.26°C and 323.33±2.08°C respectively.Bangladesh J. Sci. Ind. Res. 51(4), 261-270, 2016

scholarly journals Synthesis and Study of Zinc Orotate and its Synergistic Effect with Commercial Stabilizers for Stabilizing Poly(Vinyl Chloride)

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 194 ◽  
Author(s):  
Feng Ye ◽  
Qiufeng Ye ◽  
Haihua Zhan ◽  
Yeqian Ge ◽  
Xiaotao Ma ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Synergistic Effect ◽  
Vinyl Chloride ◽  
Zinc Stearate ◽  
Precipitation Method ◽  
Long Term Stability ◽  
Poly Vinyl Chloride ◽  
Initial Color ◽  
Thermal Stability Of

Zinc orotate (ZnOr2), which is a new kind of poly(vinyl chloride) (PVC) stabilizer, is prepared in this work through the precipitation method, and its impact on the thermal stability of PVC is measured by thermogravimetric analysis (TG), Congo red test, and discoloration test. The results exhibit that the thermal stability of PVC is positively enhanced after the addition of ZnOr2. In contrast with a commercial thermal stabilizer, zinc stearate (ZnSt2), a noteworthy improvement was observed that ZnOr2 could postpone the “zinc burning” of PVC. This is principally ascribed to the Or anion in the structure of ZnOr2 being able to absorb the HCl released by PVC, and to supersede unstable chlorine atoms in the structure of PVC. In addition, blending ZnOr2 with calcium stearate (CaSt2) in diverse mass ratios can significantly accelerate the thermal stability of PVC. Optimum performance was achieved with a CaSt2:ZnOr2 ratio of 1.8:1.2. Moreover, an outstanding synergistic effect can be observed when CaSt2/ZnOr2 is coupled with other commercial auxiliary stabilizers. The initial color and long-term stability of PVC including CaSt2/ZnOr2 is significantly increased when pentaerythritol (PER) is added, while dibenzoylmethane (DBM) can only improve its long-term thermal stability.

scholarly journals THERMAL STABILITY OF Pinus oocarpa AND MAIZE COB PARTICLEBOARDS

2015 ◽  
Vol 39 (4) ◽  
pp. 348-354 ◽  
Author(s):  
Mário Vanoli Scatolino ◽  
Thiago de Paula Protásio ◽  
Rafael Farinassi Mendes ◽  
Lourival Marin Mendes
Keyword(s):  
Thermal Stability ◽  
Agricultural Waste ◽  
Urea Formaldehyde ◽  
Curve Analysis ◽  
Raw Material ◽  
Waste Materials ◽  
Pressing Cycle ◽  
Pinus Oocarpa ◽  
Maize Cob ◽  
Thermal Stability Of

Agricultural waste materials are generated in large quantities in Brazil. These can accumulate and cause serious environmental problems. One of the most commonly generated wastes in the brazilian agricultural culture is the maize cob. Being lignocellulosic in nature, the maize cob can find use as the raw material in the production of particleboards mainly concerned with furniture making. Therefore, studies regarding its thermal stability and fire resistance would be interesting. The aim of this study was to evaluate the combustibility and thermal stability of the particleboards produced from maize cob and Pinus oocarpa wood. The percentages in which maize cob was associated with Pinus oocarpa were 0%, 25%, 50%, 75% and 100%. The panels were produced using 8% urea-formaldehyde and 1% paraffin. The pressing cycle parameters included: temperature 150 °C, pressure of 3.92 MPa during 10 min. The combustibility curve analysis showed that the panels containing 25% content of maize cob had higher resistance to combustion. In general, the thermal stability decreased as the wood substitution by maize cob increased.

Carbonate Apatite Bone Replacement

2013 ◽  
Vol 587 ◽  
pp. 17-20 ◽  
Author(s):  
Ishikawa Kunio
Keyword(s):  
Thermal Stability ◽  
Cell Response ◽  
Tissue Response ◽  
Precipitation Method ◽  
Carbonate Apatite ◽  
Inorganic Component ◽  
Bone Replacement ◽  
Thermal Stability Of

Inorganic component of bone is not hydroxyapatite but carbonate apatite. Although pure carbonate apatite (CO3Ap) has not been prepared due to the limited thermal stability of CO3Ap, dissolution - precipitation method using precursor block allows fabrication of pure CO3Ap. Fabrication of CO3Ap, cell response, tissue response and improvement of CO3Ap will be discussed.

Investigation of the thermal stability of Mn ferrite particles synthesized by a modified co-precipitation method

2012 ◽  
Vol 56 (3) ◽  
pp. 568-572 ◽  
Author(s):  
ChunHui Dong ◽  
GaoXue Wang ◽  
Lei Shi ◽  
DangWei Guo ◽  
ChangJun Jiang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Precipitation Method ◽  
Co Precipitation ◽  
Thermal Stability Of

Effect of Mg Content on Thermal Stability of β-Tricalcium Phosphate Ceramics

2014 ◽  
Vol 604 ◽  
pp. 192-195 ◽  
Author(s):  
Kristine Salma-Ancane ◽  
Liga Stipniece ◽  
Zilgma Irbe ◽  
Marina Sokolova ◽  
Guna Krieke ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Chemical Composition ◽  
Tricalcium Phosphate ◽  
Chemical Properties ◽  
Precipitation Method ◽  
Sintering Behavior ◽  
Remarkable Effect ◽  
Mg Content ◽  
Thermal Stability Of

β-Tricalcium phosphate bioceramics with small, close to bone-like amounts of Mg were obtained by modified precipitation method and following sintering. The effect of small amounts of Mg on the thermal stability, microstructure and sintering behavior of β-tricalcium phosphate bioceramics was evaluated. Addition of small amounts of Mg, can induce a remarkable effect on the physic-chemical properties of β-TCP and therefore the chemical composition of the starting materials should be controlled.

scholarly journals Influence of ingredients on the properties of the flame retardant compound based on polyethylene

2021 ◽  
Vol 63 (11) ◽  
pp. 66-69
Author(s):  
Vu Thang Tran ◽  
◽  
Thi Phuong Hoang ◽  
Ngo Vu Duong ◽  
Thi Phuong Hong Dao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Flame Retardant ◽  
Fire Resistance ◽  
Zinc Stearate ◽  
Elongation At Break ◽  
Melt Index ◽  
Melamine Phosphate ◽  
Index Value ◽  
Thermal Stability Of

In this paper, the effects of a flame retardant system combining ATH/MPP (aluminum hydroxide/melamine phosphate) and the other additives such as zinc stearate (ZnSt) on some properties of flame retardant PE compound based on LDPE were studied. The total flame retardant content was 35% by weight. Mechanical properties (tensile at break, elongation at break), thermal stability, and fire resistance were determined by the respective methods ASTM D638, thermogravimetric analysis (TGA), scanning electron microscope (SEM), and UL-94 test. The obtained results showed that using the combination of ATH/MPP has increased the fire resistance and thermal stability of the PE compound. The sample CT7 (15%ATH/20%MPP/2%ZnSt) achieved the best fire resistance. The mechanical properties increased slightly when increasing the content of MPP and reached the maximum for samples containing only MPP. The SEM micrographs showed that the addition of zinc stearate improved the dispersion of ATH and MPP in the PE matrix. The effect of flame retardant additives and zinc stearate on the melt index value of the PE compound was also surveyed.

The Thermal Stability of Monosulfidic Crosslinks in Natural Rubber

1983 ◽  
Vol 56 (2) ◽  
pp. 337-343 ◽  
Author(s):  
G. P. McSwkeeney ◽  
N. J. Morrison
Keyword(s):  
Thermal Stability ◽  
Stearic Acid ◽  
Natural Rubber ◽  
High Temperatures ◽  
Zinc Stearate ◽  
Thermally Stable ◽  
Thermal Stability Of

Abstract (1) Networks containing mainly monosuifidic crosslinks at methylene sites in the polyisoprene chains of natural rubber are expected to be more thermally stable than existing efficiently vulcanized networks. (2) Certain zinc-accelerator species promote the decomposition of crosslinks at high temperatures, but may be deactivated by complexation with zinc stearate (which is formed from stearic acid during vulcanization).

Sr- and/or Mg-Containing Nanocrystalline Hydroxyapatite: Study from Synthesis to Calcined Products

2016 ◽  
Vol 721 ◽  
pp. 167-171
Author(s):  
Liga Stipniece ◽  
Inga Narkevica ◽  
Kristine Salma-Ancane ◽  
Dagnija Loca
Keyword(s):  
Thermal Stability ◽  
Thermal Behavior ◽  
Biologically Active ◽  
Precipitation Method ◽  
Sintering Behavior ◽  
Minor Phase ◽  
Major Phase ◽  
Nanocrystalline Hydroxyapatite ◽  
Deviation From Stoichiometry ◽  
Thermal Stability Of

In this work, nanocrystalline hydroxyapatite (HAp) powders were synthesized through wet precipitation method by adjusting the reaction temperature between 0 °C and 5 °C. The influence of biologically active Mg and Sr addition on HAp crystalline structure and thermal behavior was assessed. In all synthesis, nanocrystalline and/or amorphous HAp was found to be the major phase, and was accompanied by Ca(OH)2 as the minor phase. Results suggested that Sr and Mg have an impending effect on nucleation, crystallization and thermal stability of HAp. The addition of Sr or Mg promoted deviation from stoichiometry and formation of amorphous components, which affected thermal stability and sintering behavior of the synthesis products.

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