scholarly journals Improving Thermal Stability of Polyurethane through the Addition of Hyperbranched Polysiloxane

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 697 ◽  
Author(s):  
Shang-Hao Liu ◽  
Ming-Yuan Shen ◽  
Chen-Feng Kuan ◽  
Hsu-Chiang Kuan ◽  
Cing-Yu Ke ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Hybrid Material ◽  
Addition Reaction ◽  
Sol Gel ◽  
Decomposition Temperature ◽  
Isophorone Diisocyanate ◽  
Hyperbranched Polysiloxane ◽  
Hydroxy Groups ◽  
Thermal Stability Of ◽  
Polyurethane Matrix

Polydimethylsiloxane with hydroxy groups was functionalized to form functionalized polydimethylsiloxane, which subsequently underwent an addition reaction with isophorone diisocyanate to form the prepolymer. Next, 3-aminopropyltriethoxysilane (APTS) reacted with 3-glycidoxypropyltrimethoxysilane (GPTS) to produce bridged polysilsesquioxanes, and sol-gel technology was employed to form hyperbranched polysiloxane nanoparticles with hydroxy groups, APTS-GPTS, which was used as the additive. The hyperbranched polysiloxane and the prepolymer containing NCO functional groups then underwent an addition reaction to produce the hybrid materials. Fourier-transform infrared spectroscopy and 29Si nuclear magnetic resonance were used to characterize the structure of the polyurethane hybrid. Regarding thermal stability, after the hyperbranched polysiloxane nanoparticles was introduced, the integral procedural decomposition temperature increased from 348 °C for polyurethane matrix to 859 °C for the hybrid material. The results reveal that the thermal stability of the hybrid material substantially increased by approximately 247%.

scholarly journals Improving Thermal Stability of Polyurethane through the Addition of Hyperbranched Polysiloxane

2019 ◽  
Author(s):  
Shang-Hao Liu ◽  
Ming-Yuan Shen ◽  
Chen-Feng Kuan ◽  
Hsu-Chiang Kuan ◽  
Cing-Yu Ke ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Hybrid Material ◽  
Addition Reaction ◽  
Sol Gel ◽  
Decomposition Temperature ◽  
Isophorone Diisocyanate ◽  
Hyperbranched Polysiloxane ◽  
Hydroxy Groups ◽  
Thermal Stability Of ◽  
Polyurethane Matrix

Polydimethylsiloxane with hydroxy groups was functionalized to form functionalized polydimethylsiloxane, which subsequently underwent an addition reaction with isophorone diisocyanate to form the prepolymer. Next, 3-aminopropyltriethoxysilane (APTS) reacted with 3-glycidoxypropyltrimethoxysilane (GPTS) to produce bridged polysilsesquioxanes, and the sol–gel technology was employed to form hyperbranched polysiloxane nanoparticles with hydroxy groups, which was used as the additive. The hyperbranched polysiloxane and the prepolymer containing NCO functional groups then underwent an addition reaction to produce the hybrid materials. Fourier-transform infrared spectroscopy and 29Si nuclear magnetic resonance were used to characterize the structure of the polyurethane hybrid. Regarding thermal stability, after the hyperbranched polysiloxane nanoparticles was introduced, the integral procedural decomposition temperature increased from 348 ºC for polyurethane matrix to 859 ºC for the hybrid material. The results revealed that the thermal stability of the hybrid material substantially increased by approximately 247%.

scholarly journals Preparation and Characteristics of an Environmentally Friendly Hyperbranched Flame-Retardant Polyurethane Hybrid Containing Nitrogen, Phosphorus, and Silicon

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 720 ◽  
Author(s):  
Chen ◽  
Chiang
Keyword(s):  
Thermal Stability ◽  
Flame Retardant ◽  
Hybrid Material ◽  
Functional Group ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Decomposition Temperature ◽  
Limiting Oxygen Index ◽  
Raman Analysis ◽  
Ring Opening Reaction

The NCO functional group of 3-isocyanatoproplytriethoxysilane (IPTS) and the OH functional group of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phospha-phenantbrene-10-oxide (DOPO-BQ) were used to conduct an addition reaction. Following completion of the reaction, triglycidyl isocyanurate (TGIC) was introduced to conduct a ring-opening reaction. Subsequently, a sol–gel method was used to initiate a hydrolysis–condensation reaction on TGIC–IPTS–DOPO-BQ to form a hyperbranched nitrogen–phosphorous–silicon (HBNPSi) flame retardant. This flame retardant was incorporated into a polyurethane (PU) matrix to prepare a hybrid material. Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), limiting oxygen index (LOI), UV-VIS spectrophotometry, and Raman analysis were conducted to characterize the structure and analyze the transparency, thermal stability, flame retardancy, and residual char to understand the flame retardant mechanism of the prepared hybrid material. After the flame retardant was added, the maximum degradation rate decreased from −36 to −17 wt.%/min, the integral procedural decomposition temperature (IPDT) increased from 348 to 488 °C, and the char yield increased from 0.7 to 8.1 wt.%. The aforementioned results verified that the thermal stability of PU can be improved after adding HBNPSi. The LOI analysis indicated that the pristine PU was flammable because the LOI of pristine PU was only 19. When the content of added HBNPSi was 40%, the LOI value was 26; thus the PU hybrid became nonflammable.

scholarly journals Synthesis and photocatalytic properties of Sn–TiO2 nanomaterials

2020 ◽  
Vol 10 (01n02) ◽  
pp. 2060018
Author(s):  
E. M. Bayan ◽  
T. G. Lupeiko ◽  
L. E. Pustovaya ◽  
M. G. Volkova
Keyword(s):  
Phase Transition ◽  
Thermal Stability ◽  
Sol Gel ◽  
Rutile Phase ◽  
Photocatalytic Properties ◽  
Light Activation ◽  
X Ray ◽  
Tio2 Nanomaterials ◽  
Visible Light Activation ◽  
Thermal Stability Of

Sn-doped TiO2 nanomaterials were synthesized by sol–gel method. It was shown the phase compositions and phase transitions change with the introduction of different tin amounts (0.5–20[Formula: see text]mol.%). X-ray powder diffraction was used to study the effect of different tin amounts on the anatase–rutile phase transition. It was found that the introduction of ions increases the thermal stability of anatase modifications. The material’s photocatalytic activity was studied in reaction with a model pollutant (methylene blue) photodegradation under UV and visible light activation. The best photocatalytic properties were shown for material, which contains 5[Formula: see text]mol.% of Sn.

Thermal stability of europium(III) chelate encapsulated by sol–gel glass

2009 ◽  
Vol 480 (2) ◽  
pp. 908-911 ◽  
Author(s):  
E. Kin ◽  
T. Fukuda ◽  
S. Yamauchi ◽  
Z. Honda ◽  
H. Ohara ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Sol Gel ◽  
Thermal Stability Of

scholarly journals The Thermal Properties of Polyurethane/Neoprene Blends on Prosthetic Foot

2020 ◽  
Vol 990 ◽  
pp. 106-110
Author(s):  
Mohd Zulkifli Mohamad Noor ◽  
Mohamad Anas Mohd Azmi ◽  
Mohd Shaiful Zaidi Mad Desa ◽  
Mohd Bijarimi Mat Piah ◽  
Azizan Ramli
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Low Cost ◽  
Decomposition Temperature ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Prosthetic Foot ◽  
Reinforced Polymer ◽  
New Material ◽  
Thermal Stability Of

Neoprene reinforced polymer has become an attraction in current research and development of new material blend. In this invention, neoprene was chosen to be enhance to polyurethane because of their superior properties that possess extraordinary mechanical, electrical, optical and thermal properties on prosthetic foot. In this research, polyurethane was chosen due to good rigidity, easy processing and low cost. The reinforcement polyurethane with neoprene is expected to improve the properties of polyurethane. The objective of this research was conducted to investigate the effect of neoprene contents on thermal properties of polyurethane reinforced neoprene on prosthetic foot. The effect of neoprene on thermal properties neoprene reinforced polyurethane was analysed in term of its thermal stability by thermal gravimetric analysis (TGA). Moreover, the visual of small topographic details on the surface of polyurethane/neoprene blends will be examined by scanning electron microscope (SEM). Based on result, the thermal properties show the great enhancement at high neoprene contents which is 1.0wt%. The thermal stability of polyurethane reinforced neoprene improves when the temperature where decomposition starts to occurs are higher than decomposition temperature of pure polyurethane. Then, thermal conductivity of polyurethane shows the great improvement after the addition of neoprene. Lastly, the smooth surface and visible of sheets pattern on surface represent the present of neoprene disperse into polymer that enhance brittleness. Thus, the presence of neoprene has clearly enhanced the thermal stability of the polyurethane. Table 1 shows formulation of neoprene and polyurethane.

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.

Synthesis and Thermal Stability of Nontransformable Tetragonal (ZrO2)0.96(REO1.5)0.04 (Re=Sc3+, Y3+) Nanocrystals

2013 ◽  
Vol 334-335 ◽  
pp. 60-64 ◽  
Author(s):  
Mohammad Reza Loghman-Estark ◽  
Reza Shoja Razavi ◽  
Hossein Edris
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Scanning Electron

Scandia, yttria doped zirconia ((ZrO2)0.96(REO1.5)0.04(RE=Sc3+, Y3+)) nanoparticles were prepared by the modified sol-gel method. The microstructure of the products was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Thermal stabillity of SYSZ nanocrystals were also investigated. The SYSZ nanocrystals synthesized with EGM:Zr+4mole ratio 4:1, calcined at 700°C, have average diameter of ~20 nm.

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