scholarly journals Synthesis of barium tannate from eucalyptus bark and its use as a thermal stabilizer for poly(vinyl chloride)

BioResources ◽  
2011 ◽  
Vol 6 (1) ◽  
pp. 700-706
Author(s):  
Hussein Ali Shnawa ◽  
M. Gelap Muhsen ◽  
Dia'a Abed Aldaeem ◽  
A. Kadim Ibraheem ◽  
Faise M. Gumaa ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Thermal Conditions ◽  
Outer Bark ◽  
Thermal Stabilizer ◽  
Poly Vinyl Chloride ◽  
Treated Sample ◽  
Degradation Rates ◽  
Thermal Stability Of ◽  
Eucalyptus Bark

In this work tannin was isolated from the outer bark of the eucalyptus tree, then treated with Ba(OH)2 to synthesize barium tannate (Ba-tan). The derivative was evaluated as a thermal stabilizer for polyvinyl chloride (PVC). PVC was mixed with Ba-tan thermally at four percentages (0.5, 1.0, 2.0, and 2.5)% w/w. The samples were pressed thermally to films having thickness ranging between 0.25 and 0.30 mm. The effect of Ba-tan was studied by monitoring the weight of samples under iso-thermal conditions at 250 oC. Thermal stability of PVC increased with increasing Ba-tan percent. Samples weight curves also indicated that the additive had been suitably active to increase the resistance of PVC against thermal degradation, where the degradation rates decreased from about 0.21 % wt/min. at 0.5% of Ba-tan on PVC to reach to 0.05% wt/min. for the 2.5% treated sample. The ability of Ba-tan to react with and remove HCl from the system of polymer during thermal conditioning of samples and during the measurement led to this effect. Therefore the present results demonstrate the performance of this derivative as a thermal stabilizer.

scholarly journals The Use of POSS-Based Nanoadditives for Cable-Grade PVC: Effects on its Thermal Stability

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1105 ◽  
Author(s):  
Palin ◽  
Rombolà ◽  
Milanesio ◽  
Boccaleri
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Additive Effects ◽  
Poly Vinyl Chloride ◽  
The Family ◽  
Mechanical Performances ◽  
Oligomeric Silsesquioxane ◽  
Thermal Stability Of

Plasticized–Poly(vinyl chloride) (P-PVC) for cables and insulation requires performances related to outdoor, indoor and submarine contexts and reduction of noxious release of HCl-containing fumes in case of thermal degradation or fire. Introducing suitable nanomaterials in polymer-based nanocomposites can be an answer to this clue. In this work, an industry-compliant cable-grade P-PVC formulation was added with nanostructured materials belonging to the family of Polyhedral Oligomeric Silsesquioxane (POSS). The effects of the nanomaterials, alone and in synergy with HCl scavenging agents as zeolites and hydrotalcites, on the thermal stability and HCl evolution of P-PVC were deeply investigated by thermogravimetric analysis and reference ASTM methods. Moreover, hardness and mechanical properties were studied in order to highlight the effects of these additives in the perspective of final industrial uses. The data demonstrated relevant improvements in the thermal stability of the samples added with nanomaterials, already with concentrations of POSS down to 0.31 phr and interesting additive effects of POSS with zeolites and hydrotalcites for HCl release reduction without losing mechanical performances.

scholarly journals Development and Investigation of Lanthanum Sulfadiazine with Calcium Stearate and Epoxidised Soyabean Oil as Complex Thermal Stabilizers for Stabilizing Poly(vinyl chloride)

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 531 ◽  
Author(s):  
Qiufeng Ye ◽  
Xiaotao Ma ◽  
Bobin Li ◽  
Zhe Jin ◽  
Yingying Xu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Vinyl Chloride ◽  
Calcium Stearate ◽  
Gravimetric Analysis ◽  
Thermal Stabilizer ◽  
Poly Vinyl Chloride ◽  
Water As Solvent ◽  
Vis Spectroscopy ◽  
Thermal Stability Of

Lanthanum sulfadiazine (LaSD) was synthesized from sulfadiazine and lanthanum nitrate using water as solvent under alkaline conditions, and was used as a novel rare earth thermal stabilizer to stabilize poly(vinyl chloride) (PVC). The structure of LaSD was characterized by elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR) and thermo- gravimetric analysis (TGA). The influence of lanthanum sulfadiazine with calcium stearate (CaSt2) and epoxidized soybean oil (ESBO) on stabilizing PVC was studied by using the Congo red test, oven discoloration test, UV-vis spectroscopy and thermal decomposition kinetics. The results showed that the addition of LaSD as a thermal stabilizer can significantly improve the initial whiteness and long-term stability of PVC. In addition, the synergies between LaSD, ESBO, and CaSt2 can provide outstanding improvement in the long-term thermal stability of PVC. When the ratio of LaSD/ESBO/CaSt2 is 1.8/0.6/0.6, its thermal stability time is 2193 s which is the best state for stabilizing PVC. Furthermore, comparing the reaction energy (Ea) and the variations in the conjugate double bond concentration in PVC samples, the order of thermal stability of PVC was PVC/LaSD/ESBO/CaSt2 > PVC/LaSD/ESBO > PVC/LaSD. The thermal stability mechanism of LaSD on PVC was studied by the AgCl precipitation method and FTIR spectrum. The results showed that the action of LaSD on PVC was achieved through replacing unstable chlorine atoms and absorbing hydrogen chloride.

Flammability and Thermal Degradation of Polystyrene/Cadmium Sulfate Nanocomposites

2013 ◽  
Vol 820 ◽  
pp. 84-87
Author(s):  
Zheng Zhou Wang ◽  
Charles A. Wilkie
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Cone Calorimeter ◽  
Cds Nanoparticles ◽  
Solvothermal Process ◽  
Cadmium Sulfate ◽  
Peak Heat Release Rate ◽  
Microscale Combustion Calorimeter ◽  
Combustion Calorimeter ◽  
Thermal Stability Of

Cadmin sulfate nanoparticles, hollow sphere (CdS-HS) and rode (CdS-NR) were synthesized by ultrasonic and solvothermal process, respectively. The effect of the two kinds of nanoparticles on flammability of polystyrene was investigated using cone calorimeter (Cone) and microscale combustion calorimeter (MCC). Cone data indicate that the incorporation of 1% CdS nanoparticles leads to a about 20% reduction in the peak heat release rate (PHRR) compared to the pure PS; CdS-NR is more efficient in reducing the PHRR proved by both Cone and MCC results. The TG results show that the addition of the nanoparticles mainly increases thermal stability of PS at high temepratures.

scholarly journals Effects of Zeolites on Thermal Stability of Poly(vinyl chloride)

Polymer Korea ◽  
2015 ◽  
Vol 39 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Jiayou Xu ◽  
Qinghua Liang ◽  
Xiumei Xian ◽  
Kaidan Li ◽  
Jie Liu
Keyword(s):  
Thermal Stability ◽  
Vinyl Chloride ◽  
Poly Vinyl Chloride ◽  
Thermal Stability Of

scholarly journals Differences in Thermal Stability of Glucosinolates in Five Brassica Vegetables

2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S85-S88 ◽  
Author(s):  
M. Dekker ◽  
K. Hennig ◽  
R. Verkerk
Keyword(s):  
Thermal Stability ◽  
Brussels Sprouts ◽  
Pak Choi ◽  
Red Cabbage ◽  
Indole Glucosinolates ◽  
First Order Kinetics ◽  
Degradation Rates ◽  
Brassica Vegetables ◽  
The Stability ◽  
Thermal Stability Of

The thermal stability of individual glucosinolates within five different Brassica vegetables was studied at 100°C for different incubation times up to 120 minutes. Three vegetables that were used in this study were <I>Brassica oleracea</I> (red cabbage, broccoli and Brussels sprouts) and two were <I>Brassica rapa</I> (pak choi and Chinese cabbage). To rule out the influence of enzymatic breakdown, myrosinase was inactivated prior to the thermal treatments. The stability of three glucosinolates that occurred in all five vegetables (gluconapin, glucobrassicin and 4-methoxyglucobrassicin) varied considerably between the different vegetables. The degradation could be modeled by first order kinetics. The rate constants obtained varied between four to twenty fold between the five vegetables. Brussels sprouts showed the highest degradation rates for all three glucosinolates. The two indole glucosinolates were most stable in red cabbage, while gluconapin was most stable in broccoli. These results indicate the possibilities for plant breeding to select for cultivars in which glucosinolates are more stable during processing.

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 Development of Novel Silica-Based Formulation of α-Lipoic Acid: Evaluation of Photo and Thermal Stability of the Encapsulated Drug

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 228 ◽  
Author(s):  
Ekaterina S. Dolinina ◽  
Elizaveta Yu. Akimsheva ◽  
Elena V. Parfenyuk
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Lipoic Acid ◽  
Sol Gel ◽  
Silica Matrix ◽  
Matrix Modification ◽  
Drug Stabilization ◽  
Further Development ◽  
Kinetics Of ◽  
Thermal Stability Of

Powerful antioxidant α-lipoic acid (LA) is easily degraded under light and heating. This creates difficulties in its manufacture, storage and reduces efficiency and safety of the drug. The purpose of this work was to synthesize novel silica-based composites of LA and evaluate their ability to increase photo and thermal stability of the drug. It was assumed that the drug stabilization can be achieved due to LA-silica interactions. Therefore, the composites of LA with unmodified and organomodified silica matrixes were synthesized by sol-gel method at the synthesis pH below or above the pKa of the drug. The effects of silica matrix modification and the synthesis pH on the LA-silica interactions and kinetics of photo and thermal degradation of LA in the composites were studied. The nature of the interactions was revealed by FTIR spectroscopy. It was found that the rate of thermal degradation of the drug in the composites was significantly lower compared to free LA and mainly determined by the LA-silica interactions. However, photodegradation of LA in the composites under UV irradiation was either close to that for free drug or significantly more rapid. It was shown that kinetics of photodegradation was independent of the interactions and likely determined by physical properties of surface of the composite particles (porosity and reflectivity). The most promising composites for further development of novel silica-based formulations were identified.

scholarly journals Effects of aluminum sulfate soaking pretreatment on dimensional stability and thermostability of heat-treated wood

2020 ◽  
Author(s):  
Lijie Qu ◽  
Zhenyu Wang ◽  
Jing Qian ◽  
Zhengbin He ◽  
Songlin Yi
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Thermal Degradation ◽  
Structural Changes ◽  
Aluminum Sulfate ◽  
Treated Wood ◽  
Treatment Temperature ◽  
Chinese Fir ◽  
Heat Treated ◽  
Thermal Stability Of

Abstract Acidic aluminum sulfate hydrolysis solutions can be used to catalyze the thermal degradation of wood in a mild temperature environment, and thus reduce the temperature required for heat treatment process. To improve the dimensional and thermal stability of Chinese fir during heat treatment at 120 °C, 140 °C and 160 °C, this study investigated the effects of soaking pretreatment with 5%, 10% and 15% aluminum sulfate on the chemical and structural changes of the heat-treated Chinese fir. The results indicated that the samples treated at 15% aluminum sulfate concentration and 160 °C heat treatment achieved the best dimensional and thermal stability. Chemical analyses by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) indicated that the catalysis of aluminum sulfate resulted in degradation of hemicelluloses during the heat treatment, and an increase in the soaking concentration and heat treatment temperature also affected the thermal degradation of celluloses. The scanning electron microscope (SEM) and mass changes test results proved that the hydrolyzed aluminum flocs mainly adhered to the inner wall of the wood tracheid as spherical precipitates, and when the soaking concentration reached 10% and 15%, a uniform soaking effect could be achieved. The thermogravimetric (TG) analysis revealed the soaking pretreatment effectively improved the thermal stability of the heat-treated wood by physically wrapping and promoting the formation of a carbon layer on the wood surface during heat treatment. Thus, aluminum sulfate soaking pretreatment exerted a great effect on the dimensional and thermal stability of wood, allowing heat treatment to be performed at a lower temperature.

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