Thermal Properties of Bi2O3-B2O3-ZnO Glass System

2006 ◽  
Vol 510-511 ◽  
pp. 578-581 ◽  
Author(s):  
Yu Jin Kim ◽  
Seong Jin Hwang ◽  
Hyung Sun Kim
Keyword(s):  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Lead Oxide ◽  
Lead Free ◽  
Oxide Glasses ◽  
Glass Formation Region ◽  
Formation Region ◽  
Lower Glass Transition Temperature

Oxide glasses having lower glass transition temperature are widely used in electric devices. The oxide glasses usually contain lead oxide. Recently, lead oxide glasses have been replaced with lead-free oxide glasses because of the environmental pollution. We investigated the thermal properties and the glass formation region in the Bi2O3-B2O3-ZnO ternary system. The results showed that the ratio of Tg/Tl of the bismate glasses is around 0.55, which is lower than the value of ratio 0.67, the two-third rule (Tg/ Tl=2/3)

Study on Glass Transition Temperature of Polyvinylamine Hydrochloride

2011 ◽  
Vol 217-218 ◽  
pp. 1066-1069 ◽  
Author(s):  
Hong Chi Zhao ◽  
Qi Li ◽  
Li Bin Bai ◽  
Fan Huang
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Differential Scanning Calorimeter ◽  
Degradation Rate ◽  
Average Molecular Weight ◽  
Weight Average Molecular Weight ◽  
Dsc Curves

Polyvinylamine (PVAm) was synthesized by Hofmann degradation of polyacrylamide (PAM). The thermal properties of the Polyvinylamine hydrochloride (PVAm•HCl) were studied by differential scanning calorimeter (DSC). The degradation rate (a) decreased with increasing weight-average molecular weight (Mw) of PAM and decreasing amount of NaOH, and a were the better values when the concentration of PAM was 5% and the amount of NaClO was 10 mL. DSC curves showed that the glass transition temperature (Tg) of PVAm•HCl increased with increasing Mw of PAM, concentration of NaClO and decreasing concentration of NaOH. Tg of PVAm•HCl appeared the minimum value when the concentration of PAM was 5.0%.

scholarly journals Thermal and thermodynamic characterization of a dye powder from liquid turmeric extracts by spray drying

2016 ◽  
Vol 69 (1) ◽  
pp. 7845-7854 ◽  
Author(s):  
Aura Yazmin Coronel Delgado ◽  
Héctor José Ciro Velásquez ◽  
Diego Alonso Restrepo Molina
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Mass Loss ◽  
Spray Drying ◽  
Transient Flow ◽  
Sorption Isotherms

This study aimed to evaluate the thermodynamic properties of sorption isotherms and glass transition temperature (Tg) and the thermal properties of a dye powder obtained from turmeric extracts using spray drying. The sorption isotherms were evaluated at 15, 25 and 35 °C using the dynamic gravimetric method, wherein the isotherm data of the experiment were fit to GAB and BET models. Likewise, the Tg was measured using differential scanning calorimetry (DSC). Thermogravimetric analysis (TGA) was used to determine the mass loss, and the thermal properties (heat capacity, diffusivity and thermal conductivity) were determined using transient flow method. The results demonstrated that the GAB model best fit the adsorption data. The DSC analysis presented a glass transition temperature of 65.35 °C and a loss of volatiles at 178.07 °C. The TGA analysis indicated a considerable mass loss starting at 193 °C, resulting in degradation of the product. The thermal properties demonstrated a heat capacity of 2.45 J/g °C, a thermal conductivity of 0.164 ± 0.001 W/mK and a thermal diffusivity of 8.7x10-8 ± 0.000 m2/s.

Thermal Properties of Acrylic Resin Denture Base Material Containing Silver Nanoparticle Synthesized from Aqueous Extract of Boesenbergia rotunda

2018 ◽  
Vol 777 ◽  
pp. 173-177
Author(s):  
Panjaporn Wongwitthayakool ◽  
Matsayapan Pudla
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Base Material ◽  
Acrylic Resin ◽  
Denture Base ◽  
Acrylic Resins ◽  
Thermal Stability Of

Silver nanoparticles (AgNPs) were synthesized by bioreduction method using aqueous extracts of Boesenbergia rotunda as reducing and stabilizing agents. Ultraviolet-Visible (UV-Vis) spectrophotometer was utilized to monitor the qualitative formation of AgNPs. The UV-Vis spectrum showed that the spherical AgNPs with diameter of 20-40 nm were formed. The antifugal activity of synthesized AgNPs was investigated using Candida albicans, which was found that the synthesized AgNPs could be used as effective growth inhibitors. The influence of the incorporation of prepared AgNPs on thermal properties of the acrylic denture base material was investigated. Glass transition temperature of filled acrylic resins was studied using the dynamic mechanical analyzer (DMA). The temperature sweeps were performed with tension mode. Thermogravimetry analysis (TGA) was used to examine effect of AgNP concentration and thermocycling (1250, 2500, 5000, and 10000 cycles) on thermal stability of AgNP filled acrylic resin denture base materials. Glass transition temperature (Tg) of the acrylic resins slightly increase with increasing AgNP contents. TGA results indicated that AgNP retarded thermal degradation of acrylic resin denture material, and thermocycling did not affect thermal stability of AgNP filled acrylic resin denture material.

Evaluation of Influence of the Addition Nanofillers on the Mechanical and Thermal Properties Terpolymers Ester-Ether-Amide

2014 ◽  
Vol 59 (1) ◽  
pp. 237-239
Author(s):  
A. Kozłowska ◽  
M. Piatek-Hnat
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Thermoplastic Elastomer ◽  
Nanocomposite Materials ◽  
Polymeric Matrix ◽  
Mechanical And Thermal Properties ◽  
Positive Effect

Abstract The results of studies of mechanical and thermal properties of synthesized elastomeric nanocomposites have been presented. An elastomeric multiblock terpoly(ester-b-ether-b-amide)s as polymeric matrix and nanoparticles SiO2 i TiO2 used as fillers. It was shown that the introduction of multiblock thermoplastic elastomer matrix of SiO2 and TiO2 nanoparticles allows to obtain nanocomposite materials with improved mechanical properties compared to the terpolymer before modification. An increase in glass transition temperature, which has a positive effect for the processing of terpolymers.

scholarly journals Direct cryopreservation of adherent cells on an elastic nanofiber sheet featuring a low glass-transition temperature

RSC Advances ◽  
2017 ◽  
Vol 7 (81) ◽  
pp. 51264-51271 ◽  
Author(s):  
Onon Batnyam ◽  
Shin-ichiro Suye ◽  
Satoshi Fujita
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Electrospun Nanofibers ◽  
Freezing Temperature ◽  
Adherent Cells ◽  
Mesh Structure ◽  
Cell Material ◽  
Lower Glass Transition Temperature

Electrospun nanofibers, featured a lower glass-transition temperature than the freezing temperature and a loose mesh structure, allows the direct cryopreservation of adherent cells towards the investigation of cell-material composites.

Influence of Electron Beam Irradiation and Step-Crosslinking Process on Solvent Penetration and Thermal Properties of Natural Rubber Vulcanizates

2005 ◽  
Vol 13 (1) ◽  
pp. 93-103 ◽  
Author(s):  
M. Madani ◽  
M.M. Badawy
Keyword(s):  
Thermal Conductivity ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Cross Linking ◽  
Beam Irradiation ◽  
Cross Link ◽  
Link Density ◽  
Cross Link Density

The influence of both beam irradiation and step cross-linking on high abrasion furnace (HAF) carbon black loaded natural rubber (NR) vulcanizates are reported. With irradiation, a higher cross-link density, ν, thermal conductivity, λ, and glass transition temperature, Tg, have been observed for such materials, as compared with the un-irradiated ones. There is also a decreased specific heat capacity, Cp. Meanwhile, the step cross-linking process has a slight effect on the cross-link density, glass transition temperature and thermal properties of these composites. The results of such changes in thermal conductivity are explained with the help of a simple modified model.

scholarly journals Molecular Dynamics Simulation-Based Study on Enhancing Thermal Properties of Graphene-Reinforced Thermoplastic Polyurethane Nanocomposite for Heat Exchanger Materials

2020 ◽  
Author(s):  
Animesh Talapatra ◽  
Debasis Datta
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Md Simulation ◽  
Thermoplastic Polyurethane ◽  
Simulation Based ◽  
Simulation Results

Molecular dynamics (MD) simulation-based development of heat resistance nanocomposite materials for nanoheat transfer devices (like nanoheat exchanger) and applications have been studied. In this study, MD software (Materials Studio) has been used to know the heat transport behaviors of the graphene-reinforced thermoplastic polyurethane (Gr/TPU) nanocomposite. The effect of graphene weight percentage (wt%) on thermal properties (e.g., glass transition temperature, coefficient of thermal expansion, heat capacity, thermal conductivity, and interface thermal conductance) of Gr/TPU nanocomposites has been studied. Condensed-phase optimized molecular potentials for atomistic simulation studies (COMPASS) force field which is incorporated in both amorphous and forcite plus atomistic simulation modules within the software are used for this present study. Layer models have been developed to characterize thermal properties of the Gr/TPU nanocomposites. It is seen from the simulation results that glass transition temperature (Tg) of the Gr/TPU nanocomposites is higher than that of pure TPU. MD simulation results indicate that addition of graphene into TPU matrix enhances thermal conductivity. The present study provides effective guidance and understanding of the thermal mechanism of graphene/TPU nanocomposites for improving their thermal properties. Finally, the revealed enhanced thermal properties of nanocomposites, the interfacial interaction energy, and the free volume of polymer nanocomposites are examined and discussed.

Effects of Electron Beam on Irradiated Polyimide/Polyaniline Composites

2012 ◽  
Vol 550-553 ◽  
pp. 861-864 ◽  
Author(s):  
Sunan Tiptipakorn ◽  
Piriyathorn Suwanmala ◽  
Kasinee Hemvichian ◽  
Yingpit Pornputtanakul
Keyword(s):  
Electrical Conductivity ◽  
Electron Beam ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Radiation Dose ◽  
Radiation Doses ◽  
Pani Composite ◽  
Polyaniline Composites

In this study, the composites prepared from polyimide (PI) and polyaniline (PANI) were radiated with electron beam (EB) at the radiation doses of 0, 50, 150, 200, and 300 kGy. The electrical conductivity and thermal properties of the radiated composites were determined and compared with those of the composites doped with 6M HCl. The results revealed that the electrical conductivity was enhanced from 3.42 x 10-16 S/cm (untreated polyimide without polyaniline) to 6.97 x 10-5 S/cm when the PI/PANI composite was doped with HCl at 10 phr of PANI; furthermore, the conductivity was increased to 2.16 x 10-4 S/cm for the composite at 10 phr of PANI with radiation dose of 200 kGy. In addition, it was found that the glass transition temperature of the composite was increased with the increase of PANI content for either EB radiation method or protonic acid doping method. It could be noted that the electrical conductivity values of the radiated composites were higher than those of composites doped with HCl at the same PANI content.

Investigation of the Thermal Properties of Different Grades Polyamide 12 (PA12) in Improving Laser Sintering Process (SLS)

2014 ◽  
Vol 548-549 ◽  
pp. 294-296 ◽  
Author(s):  
Yusoff Way ◽  
D.T. Pham ◽  
K.D. Dotchev
Keyword(s):  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Melting Temperature ◽  
Crystallization Temperature ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Sintering Process ◽  
Melt Flow Rate

Selective Laser Sintering (SLS) is a combined technology of computer and laser to produce complex 3D prototypes directly from CAD modeling. One of the main advantages of employing this technology is that the non-sintered powder can be recycled and reused for another fabrication. However, the fabricated part could be affected by rough and unacceptable surface texture. As a result, the parts may have to be scrapped and the build has to be repeated with a higher ratio of new material. This paper presents an experimental study of the thermal properties of new and recycled of PA12 powder in the Laser Sintering process. The influence of melting temperature, glass transition temperature and crystallization temperature on these properties is investigated. The experimental results have shown that PA12 powder with high melt flow rate, low melting temperature, low glass transition temperature and low degree of crystallization temperature could improve the sintering process.

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