scholarly journals Structures and Properties of Self - crosslinking Silicone Resin

2018 ◽  
Vol 38 ◽  
pp. 02019
Author(s):  
Yong-xin Zhao ◽  
Ying-qiang Zhang

Highly transparent silicone resin with self-crosslinking structure was prepared using phenyltrimethoxysilane, diphenyldimethoxysilane, 1,3,5,7-cyclotetra(methyl siloxane) and bisvinyltetramethyldisiloxane as main raw materials. The structure of silicone resin was determined by Fourier Transform Infrared Spectroscopy (FT-IR). The light transmittance was measured by UV-Vis spectroscopy. Thermogravimetric analysis (TGA) was used to study the thermal decomposition process. The microstructure of cured self-crosslinking silicone resin is more uniform, resulting in better light transmittance up to 100% in the range of 400nm ~ 800nm. The cured has relatively good heat resistance, the initial thermal decomposition temperature of the cured could be up to 315.8 °C. SEM observations show that the self-crosslinking silicone has a uniform, textured structure, higher transparency compared with the existing condensation silicone material, and can be used as advanced architectural translucent materials and optics packaging materials.

2011 ◽  
Vol 335-336 ◽  
pp. 128-131
Author(s):  
Shu Hong Ba ◽  
Zhen Xing Sun ◽  
Zhe Zhang ◽  
Chun Hong Zhang

CuO nanocrystal has been successfully synthesized by adopting liquid phase reaction and using cupric nitrate and sodium hydroxide as raw materials. The prepared products are characterized by XRD, FT-IR and TEM. The catalysis of CuO Nanocrystal on KClO4 is investigated by thermal analysis. The results show that CuO nanocrystal is consisted of the mixture of spherical nanoparticles with an average sizes of 11nm. The catalysis of CuO nanocrystal on KClO4 thermal decomposition was strong. And it makes thermal decomposition temperature of KClO4 to decrease 97.7 °C, the decalescence amount also reduced to 79.07 J/g. But the addition of CuO nanocrystal has no effect on the crystal shape transformation of KClO4.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 165
Author(s):  
Sandip Madhukar Deshmukh ◽  
Mohaseen S. Tamboli ◽  
Hamid Shaikh ◽  
Santosh B. Babar ◽  
Dipak P. Hiwarale ◽  
...  

In the present work, we have reported a facile and large-scale synthesis of TiO2 nanoparticles (NPs) through urea-assisted thermal decomposition of titanium oxysulphate. We have successfully synthesized TiO2 NPs by using this effective route with different weight ratios of titanium oxysulphate: urea. The structures and properties of TiO2 NPs were confirmed by scanning electron microscope) (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR), ultra violet–visible spectroscopy (UV-vis), and photoluminescence (Pl) techniques. XRD demonstrated that TiO2 NPs holds of anatase crystal phase with crystallizing size 14–19 nm even after heating at 600 °C. TGA, SEM, and TEM images reveal urea’s role, which controls the size, morphology, and aggregation of TiO2 NPs during the thermal decomposition. These TiO2 NPs were employed for photodegradation of Methyl Orange (MO) in the presence of ultraviolet (UV) radiation. An interesting find was that the TiO2 NPs exhibited better photocatalytic activity and excellent recycling stability over several photodegradation cycles. Furthermore, the present method has a great perspective to be used as an efficient method for large-scale synthesis of TiO2 NPs.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4785
Author(s):  
Maria Zielecka ◽  
Anna Rabajczyk ◽  
Krzysztof Cygańczuk ◽  
Łukasz Pastuszka ◽  
Leszek Jurecki

Silicone resins are widely applied as coating materials due to their unique properties, especially those related to very good heat resistance. The most important effect on the long-term heat resistance of the coating is connected with the type of resin. Moreover, this structure is stabilized by a chemical reaction between the hydroxyl groups from the organoclay and the silicone resin. The novel trends in application of silicone resins in intumescent paints used mostly for protection of steel structures against fire will be presented based on literature review. Some examples of innovative applications for fire protection of other materials will be also presented. The effect of silicone resin structure and the type of filler used in these paints on the properties of the char formed during the thermal decomposition of the intumescent paint will be discussed in detail. The most frequently used additives are expanded graphite and organoclay. It has been demonstrated that silicate platelets are intercalated in the silicone matrix, significantly increasing its mechanical strength and resulting in high protection against fire.


2011 ◽  
Vol 335-336 ◽  
pp. 891-894
Author(s):  
Shuan Li Du ◽  
Jian Feng Gao ◽  
Zhong Zhan Sun ◽  
Jing Yu Wang

1,4-butylene bi-p-hydroxybenzoate (BBHB) was synthesized using methyl p-hydroxyl- benzoate and 1,4-butanediol under catalyst and stabilizer conditions; Then, the thermotropic main- chain liquid crystalline polysiloxanes (MCLCPs) with flexible spacer, were synthesized using BBHB and dimethyldiethoxysilane reagents by melting polycondensation. The chemical structures and properties were characterized by FT-IR, polarized optical microscopy (POM) and differential scanning calorimeter (DSC) respectively. It was found that MCLCPs was the type of smectic A liquid crystal, and the liquid crystal temperature ranged from 58°C to 143°C, i.e. its variationrange reached 85°C. In addition, the polysiloxane was used as the flexible main-chain and the flexible chains CH2 was embedded into the rigid structural blocks of liquid crystalline polymers, which not only decreased the melting point below the thermal decomposition temperature, but also made the clearing point and a stable liquid crystal state observed.


2016 ◽  
Vol 847 ◽  
pp. 241-248 ◽  
Author(s):  
Ya Juan Wang ◽  
Ya Li ◽  
Xin Zhang ◽  
Ning Kun Wu ◽  
Shuang Xi Shao

In order to reduce the pollution of the waste material, the waste leather powder tanned with vegetable tannin was used in this work, and vinyitrimethoxy silane was chosen as coupling agent. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to investigate the thermal properties of the powder sample. Both thermal decomposition temperature and denaturation temperature of the modified sample were higher than those of the raw samples due to the interaction between leather powder and silane, which can be demonstrated by Scanning Electron Microscopy-Energy Dispersive Spectrometer (SEM-EDS) and Fourier Transform Infrared Spectroscopy (FT-IR). Additionally, the flowing property, hydrophilicity and water absorption rate of the powder samples was also examined. The results showed that the hydrophilicity and moisture absorption of the leather powder sample modified with silane was lower than the raw materials. And the flowing properties of the modified samples also decreased because of the coupling reaction of the flexible vinyitrimethoxy silane.


NANO ◽  
2018 ◽  
Vol 13 (06) ◽  
pp. 1850069 ◽  
Author(s):  
Run Chen ◽  
Gang Li ◽  
Weiyang Bai ◽  
Shuang Bao ◽  
Zhiliang Cheng

The development of highly active catalysts for the pyrolysis of ammonium perchlorate (AP) is of considerable importance for AP-based composite solid propellant. In the present study, we produced porous MgFe2O4 architectures by using a facile two-step strategy. A rod-like precursor of MgFe2(C2O[Formula: see text]O (diameter: 0.5–2.5[Formula: see text][Formula: see text]m; length: 2–15[Formula: see text][Formula: see text]m) was fabricated under solvothermal conditions using metal sulfates as raw materials and oxalic acid as the precipitant. Subsequently, porous MgFe2O4 architectures were obtained by the thermal treatment of the as-prepared oxalate precursor, during which the mesopores were formed in situ via the liberation of volatile gases, while the rod-like morphology was well preserved. The catalytic performances of the as-synthesized porous rod-like MgFe2O4 architectures with respect to the AP pyrolysis were assessed using differential scanning calorimetry (DSC) techniques. The results indicated that the high thermal decomposition temperature and the apparent activation energy of AP with 2[Formula: see text]wt.% MgFe2O4 addition decreased from 445.4[Formula: see text]C to 386.7[Formula: see text]C and from [Formula: see text] to [Formula: see text][Formula: see text]kJ mol[Formula: see text], respectively. Meanwhile, the decomposition heat of AP with MgFe2O4 as the additive reached up to 1230.6[Formula: see text]J g[Formula: see text], which was considerably higher than that of its neat counterpart (695.8[Formula: see text]J g[Formula: see text]. Thus, porous rod-like MgFe2O4 architectures could be served as the catalyst for the AP pyrolysis.


2012 ◽  
Vol 554-556 ◽  
pp. 787-791
Author(s):  
Jin Hua Zhou ◽  
Xun Jun Du ◽  
Han Zhou Sun ◽  
Yu Xiong Wu ◽  
Xiao Feng Tan ◽  
...  

Started from Tung oil, a renewable biomass material of china, a new kind of bismaleimide, Tung oil-based bi-dihydrogen-maleimide (TOBBDHMI) was synthesized by the reaction of methyl-α-eleostearate-maleic anhydride adduct (MEMAA) and 4,4'-diphenylmethane disocyanate (MDI). The optimal conditions for synthesis were catalyst triethylamine dosage 1.0%, mole ratio of MEMAA to MDI 2.4:1, reaction temperature 75°C and reaction time 2 h, which gave yield 82.4% for TOBBDHMI (calculated from MDI). The melting point of the product was 186.6 °C~189.3 °C, initial decomposition temperature was 270 °C and final decomposition temperature was 510 °C, which showed the product has good heat resistance. The target product is potential to be used alone or with other bismaleimide monomers to improve polymeric materials’ heat resistance and/or mechanical properties.


2020 ◽  
Vol 987 ◽  
pp. 64-69
Author(s):  
Dan Peng ◽  
Qiu Hong Mu ◽  
Shuo Zhang ◽  
Wei Ju ◽  
Feng Wang ◽  
...  

One component room temperature vulcanized (RTV) silicone resin was prepared by combination of a kind of D-T polysiloxane block copolymer with crosslinker and catalyst. Transparent coating with good elastoplasticity without any inorganic filler could be obtained by exposing the RTV silicone to air at room temperature. The structure of D-T block copolymer played an important role in the properties of the cured products. It was synthesized by polycondensation of partially hydrolyzed phenyltrimethoxysilane (phenylsilsesquioxane, T units) with silanol end-capped polydimethylsiloxane (PDMS, D units). The effects of the viscosity of phenylsilsesquioxane and the D/T ratio on the properties of cured product were investigated. When phenylsilsesquioxane (10000cP at 80°C) was used and the D/T ratio was 2.0~2.3, cured products with tensile strength above 2.5MPa and elongation above 70% were prepared. RTV silicone resin composed of such kind of D-T block copolymer had good heat resistance because the existence of phenyl group and the highly cross-linked 3D structure. The Tonset was 387.6°C and the Tmax was 518°C.


2013 ◽  
Vol 395-396 ◽  
pp. 423-426 ◽  
Author(s):  
Zhi Ming Jin ◽  
Wen Lu Guo ◽  
Cai Hua Gao

The waterborne polyurethane (WPU) modified by epoxy resin was synthesized by using isophorone diisocyanate (IPDI), poly propylene glycol (PPG-1000), 2,2-dimethylol propionic acid (DMPA) and epoxy resin as the main raw materials. The WPU properties were characterized by TGA, FTIR, and so on. The study shows that whennNCO/nOH=1.4, the mount of DMPA is 5.0%, the emulsifying property of WPU which is modified epoxy resin with high epoxy value is well. And when the mounts of E-20, E-44 are 2.0%, 4.0% respectively, the synthesized emulsion with small size has well stability. The modified WPU which possesses high hardness, low water absorption, good heat resistance and anticorrosion, has a well combination property.


2012 ◽  
Vol 472-475 ◽  
pp. 614-617
Author(s):  
Guang Xian Zhang ◽  
Hong Mei Ju ◽  
Feng Xiu Zhang ◽  
Lin Xiao Jing

In this paper, the raw silks were soaked in NaSCN solution, and drown to increase the broken strength. The result showed that after the raw silk was in NaSCN solution, the silk could be drown 1.46 times. The broken strength of the drown silk increased greatly. But the broken elongation decreased greatly. The washing process could increase the broken strength of drown silk. After the drown silk was washed with worm pure water, the broken strength of the drown silk could reached to 0.72 GPa, and the broken elongation recovered very well. The FT-IR spectra, DSC and X-ray diffraction spectra showed the drown silk has more oriented β-sheet crystalline structure, and the thermal decomposition temperature of drown silk increased 10 oC than normal silk. The results showed drowing silk is an efficient method to increase the strength of the silkworm silk.


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