Thermal Stability and Kinetics of the Thermal Degradation of Thermal Conductive Silicone Rubber Filled with Al2O3 and ZnO

2018 ◽  
Vol 926 ◽  
pp. 45-50 ◽  
Author(s):  
Qiu Hong Mu ◽  
Dan Peng ◽  
Feng Wang ◽  
Jin Hui Li ◽  
Shuo Zhang
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Silicone Rubber ◽  
Conductive Filler ◽  
Nitrogen Atmosphere ◽  
Zero Order ◽  
Temperature Sensitive ◽  
Conductive Silicone Rubber ◽  
Kinetics Of ◽  
Thermal Stability Of

The kinetics of the thermal degradation and thermal stability of thermal conductive silicone rubber filled with Al2O3 and ZnO were investigated by thermogravimetric analysis in a flowing nitrogen atmosphere at a heating rate of 10°C/min. The rate parameters were evaluated by the method of Freeman–Carroll. The results show that the thermal degradation of silicone rubber begins at about 350°C and ends at about 600°C. The thermal degradation is multistage, in which zero-order reactions are principal. The kinetics of the thermal degradation of thermal conductive silicone rubber has relevance to its loading of thermal conductive filler. The activation energies are temperature-sensitive and their sensitivity to temperature becomes weak as temperature increases.

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.

Thermal Degradation Study of Functionalized MWNT Reinforced Segmented Polyurethane Membrane

2006 ◽  
Vol 38 (3) ◽  
pp. 261-271 ◽  
Author(s):  
S. Mondal ◽  
J. L. Hu
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Nitrogen Atmosphere ◽  
Segmented Polyurethane ◽  
Degradation Study ◽  
Heat Treated ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Thermal Stability Of ◽  
Mwnt Content

The thermal degradation of polytetramethylene glycol (PTMG, Mn 1/42900) based polyurethane (PU), along with four different weight contents (such as 0.25, 0.50, 1.0, and 2.5 wt%) of functionalized multiwalled nanotube (MWNT) reinforced PUs are studied in air as well as in nitrogen atmosphere. The degradation results are reported in 10 and 50% weight loss and derivative of thermogravimetry (DTG). As expected, PUs are thermally more stable in nitrogen than in air. However, the influence of MWNT content on thermal stability is unclear. At 0.25 and 0.50 wt% of MWNT content, thermal stability declined and a further increase of MWNT improved the thermal stability of PU. Fourier-transform infrared (FTIR) analysis is also performed for untreated and heat treated films in order to understand the degradation at different temperatures. Free C1/4O stretching neck dimension increases with increasing temperature which signifies breaking of H-bonding detected by FTIR measure ments.

Thermal degradation kinetics of oxo-degradable PP/PLA blends

2018 ◽  
Vol 39 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Dev K. Mandal ◽  
Haripada Bhunia ◽  
Pramod K. Bajpai
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Kinetic Parameters ◽  
Degradation Kinetics ◽  
Nitrogen Atmosphere ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Kinetics Of

AbstractIn this article, the influence of polylactide and pro-oxidant on the thermal stability, degradation kinetics, and lifetime of polypropylene has been investigated using thermogravimetric analysis under nitrogen atmosphere at four different heating rates (i.e. 5, 10, 15, and 20°C/min). The kinetic parameters of degradation were studied over a temperature range of 30–550°C. The derivative thermogravimetric curves have indicated single stage and two stage degradation processes. The activation energy was evaluated by using the Kissinger, Kim-Park, and Flynn-Wall methods under the nitrogen atmosphere. The activation energy value of polypropylene was much higher than that of polylactide. Addition of polylactide and pro-oxidant in polypropylene decreased the activation energy. The lifetime of polypropylene has also decreased with the addition of polylactide and pro-oxidant.

Effect of Blend Ratio on the Mechanical and Thermal Properties of Polyurethane/Silicone Rubber Conductive Material

2018 ◽  
Vol 280 ◽  
pp. 264-269
Author(s):  
Heng Chun Wei ◽  
Teh Pei Leng ◽  
Yeoh Chow Keat
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Thermal Properties ◽  
Silicone Rubber ◽  
Conductive Filler ◽  
Material Testing ◽  
Testing System ◽  
Mechanical And Thermal Properties ◽  
Blend Ratio ◽  
Thermal Stability Of

This work reports on mechanical and thermal properties of a novel polymer blend. Blends were prepared by mixing silicone rubber with diphenyl – 4,4 – dissocyanate in different ratios. Graphene nanoplatelets was added as conductive filler to improve the electrical conductivity of the blends. The mechanical properties, including tensile and tear performances were measured by a material testing system. The thermal stability of the blends was measured by thermogravimetric analysis. Incorporation 20 vol.% of silicone rubber can help to improve the thermal stability of the blend, meanwhile optimum mechanical properties of the blends is achieved.

scholarly journals How the Crosslinking Agent Influences the Thermal Stability of RTV Phenyl Silicone Rubber

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 88 ◽  
Author(s):  
Chen He ◽  
Boqian Li ◽  
Ying Ren ◽  
Wu Lu ◽  
Yibing Zeng ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Mass Spectrum ◽  
Thermal Degradation ◽  
Silicone Rubber ◽  
Degradation Mechanism ◽  
Tg Analysis ◽  
Oh Groups ◽  
Thermal Degradation Mechanism ◽  
Thermal Stability Of ◽  
Crosslinking Agents

In this work, a thermal degradation mechanism of room temperature vulcanized (RTV) phenyl silicone rubber that was vulcanized by different crosslinking agents was discussed. Firstly, RTV phenyl silicone rubber samples were prepared by curing hydroxyl-terminated polymethyldiphenylsiloxane via three crosslinking agents, namely, tetraethoxysilane (TEOS), tetrapropoxysilane (TPOS), and polysilazane. Secondly, the ablation properties of RTV phenyl silicone rubber were studied by the muffle roaster test and FT-IR. Thirdly, thermal stability of the three samples was studied by thermogravimetric (TG) analysis. Finally, to explore the thermal degradation mechanism, the RTV phenyl silicone rubber vulcanized by different crosslinking agents were characterized by TG analysis-mass spectrum (TG-MS) and pyrolysis gas chromatogram-mass spectrum (pyGC-MS). Results showed that the thermal stability of RTV phenyl silicone rubber is related to the amount of residual Si–OH groups. The residual Si–OH groups initiated the polysiloxane chain degradation via an ‘unzipping’ mechanism.

Research on Thermal Degradation Kinetics of Polyphenylene Sulfide Filter Media

2013 ◽  
Vol 300-301 ◽  
pp. 1171-1174 ◽  
Author(s):  
De Qiang Chang ◽  
Jing Xian Liu ◽  
Ning Mao ◽  
Bao Zhi Chen
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Decomposition Temperature ◽  
Polyphenylene Sulfide ◽  
Thermal Degradation Kinetics ◽  
Filter Media ◽  
Initial Decomposition Temperature ◽  
Kinetics Of ◽  
Thermal Stability Of

In order to study the thermal stability of PPS (polyphenylene sulfide) filter media, by means of thermogravimetry(TG), thermal degradation kinetics behavior of two kinds of PPS filter media were analyzed. The kinetic parameters of PPS filter media were obtained according to Flynn-Wall-Ozawa method. Thermal stability of PPS filter media was discussed. It was found that the initial decomposition temperature and activation energy of N3 sample are all higher than B1 sample, the thermal stability of N3 sample is better than B1 sample, and kinetic analysis can be used as an important method to evaluate the thermal stability of filter media.

Investigation of Thermal Stability of Zn(II), Pt(II) and Pd(II) Complexes with (E)-2-oxo-2-{N'-[1-(pyridin-2-yl)ethylidene]hydrazino}acetamide

2005 ◽  
Vol 494 ◽  
pp. 375-380
Author(s):  
Tamara R. Todorović ◽  
K.K. Andjelković ◽  
D.M. Sladić ◽  
D.A. Jeremić ◽  
D. Minić
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Structural Transformation ◽  
Structural Rearrangement ◽  
Nitrogen Atmosphere ◽  
Crystal Water ◽  
Temperature Range ◽  
Square Planar ◽  
Thermal Stability Of

Thermal stability of neutral Zn(II), Pd(II) and Pt(II) complexes of formulae [Zn(apsox)2]·3H2O and [M(apsox)Cl] (M=Pd(II), Pt(II), HL=(E)-2-oxo-2-{N ’-[1-(pyridin-2- yl)ethylidene]hydrazino}acetamide) were studied. The results of DSC and TG analyses within the temperature range from 20 to 600 °C in nitrogen atmosphere showed that the loss of crystal water represents the first step during decomposition of the octahedral Zn(II) complex followed by structural rearrangement of its anhydrous form. After that the complex remained stable to about 330 °C. Different from neutral square-planar Pd(II) and Pt(II) complexes, a satisfactory resolution of the peaks in DSC of the Zn(II) complex enabled determination of the activation energies of its structural transformation and thermal degradation.

Thermal degradation kinetics of PP/PLA nanocomposite blends

2018 ◽  
Vol 32 (12) ◽  
pp. 1714-1730 ◽  
Author(s):  
Dev K Mandal ◽  
Haripada Bhunia ◽  
Pramod K Bajpai
Keyword(s):  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Frequency Factor ◽  
Nitrogen Atmosphere ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Degradation Kinetic ◽  
Thermal Degradation Behavior ◽  
Kinetics Of ◽  
Thermal Stability Of

In this article, the effect of adding polylactide (PLA) and nanoclay on the thermal stability of polypropylene (PP) films was analyzed using thermogravimetric analysis. The thermal degradation kinetic parameters such as activation energy ( Ea), order of reaction ( n), and frequency factor (ln ( Z)) of the samples were studied over a temperature range of 30–550°C. Analyses were performed under nitrogen atmosphere with four different heating rates (i.e. 5, 10, 15, and 20°C min−1). The Ea was calculated by Kissinger, Kim–Park, and Flynn–Wall methods. The Ea value of PP was much higher than PLA, whereas the addition of PLA and nanoclay in PP decreased the Ea. The addition of compatibilizer increased the compatibility and Ea of blended films upto some extent. The lifetime of PP was found to be decreased with the addition of PLA and nanoclay. Studies indicated that the thermal degradation behavior and lifetime of the investigated samples depend on the fractions of constituents and heating rates.

Thermal Properties and Thermal Degradation Kinetics of Polypropylene/ Organomodified Ni-Al Layered Double Hydroxide (LDH) Nanocomposites Prepared by Melt Intercalation Technique

2011 ◽  
Vol 471-472 ◽  
pp. 209-214 ◽  
Author(s):  
Kaberi Kakati ◽  
Aditya Prakash ◽  
G. Pugazhenthi
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Sodium Dodecyl ◽  
Decomposition Temperature ◽  
Thermal Degradation Kinetics ◽  
Precipitation Method ◽  
Melt Intercalation ◽  
Kinetics Of ◽  
Thermal Stability Of

The objective of this work is to investigate the influence of LDH loading on the thermal stability and thermal degradation kinetics of the PP/Ni-Al LDH nanocomposites using thermogravimetric analysis (TGA) and to compare the results with that of the neat PP. For this, Ni-Al LDH was first prepared by co-precipitation method at constant pH using their nitrate salts and subsequently organically modified using sodium dodecyl sulphate (SDS) by regeneration method. A series of novel PP/Ni-Al LDH nanocomposites was then prepared with various amounts of LDH by melt intercalation method. The XRD results confirm the formation of exfoliated PP/LDH nanocomposites. PP/LDH nanocomposites exhibit enhanced thermal stability relative to the neat PP due to the presence of barrier effect of LDH lamellar layers and the thermal stability of the nanocomposites also increases with increase in the LDH loading. When 10% weight loss is selected as a point of comparison, the decomposition temperature of PP/LDH (5 wt %) nanocomposite is 15 oC higher than that of neat PP. The thermal degradation activation energy of the nanocomposites is determined via Coats-Redfern method and compared with that of neat PP. The improvement of thermal stability of PP nanocomposites is also confirmed by increasing the activation energies (Ea) and the integral procedural decomposition temperature (IPDT) compared with neat PP. Criado method is finally used to determine the degradation reaction mechanism of various samples.

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