scholarly journals Thermochemical Properties of Nicotine Salts

2001 ◽  
Vol 19 (6) ◽  
pp. 289-295
Author(s):  
DM Riggs ◽  
TA Perfetti
Keyword(s):  
Sample Size ◽  
Elevated Temperatures ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Sample Weight ◽  
Crystalline Materials ◽  
Size Dependent ◽  
Liquid Salt ◽  
Endotherm Peak

AbstractThe thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) results presented in this report clearly show that the thermal stability and the endothermic peak nicotine release temperatures are different for different nicotine salts and these temperatures appear to be linked to the general microstructural details of the salt itself. In addition, the peak nicotine release temperatures are highly dependent upon the sample size used. The heat of vaporization for neat (non-protonated) nicotine is also sample-size dependent. The TGA data showed that the least stable of the salts tested at elevated temperatures was the liquid salt nicotine triacetate followed by the crystalline materials (e.g., nicotine gallate) and finally, the amorphous salts (e.g., nicotine alginate). The DSC results revealed that the liquid and crystalline salts exhibit nicotine release endotherms that are strongly related to the sample weight being tested. The amorphous salts show nicotine endotherm peak temperatures that are nearly independent of the sample weight. The range of peak nicotine release temperatures varied depending upon the specific salts and the sample size from 83 oC to well over 200 oC. Based on these results, the evolution of nicotine from the nicotine salt should be expected to vary based on the composition of the salt, the details of its microstructure, and the amount of nicotine salt tested.

Synthesis, Characterization and Application of Multi-Generations Hyperbranched Polyurethane Based on Isophorone Diisocyanate

2012 ◽  
Vol 554-556 ◽  
pp. 126-129 ◽  
Author(s):  
Shun Yin ◽  
Ning Sun ◽  
Chun Yun Feng ◽  
Zhi Mou Wu ◽  
Zhao Hua Xu ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raw Materials ◽  
Degradation Mechanism ◽  
Resonance Spectroscopy ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Isophorone Diisocyanate ◽  
Scanning Calorimetry ◽  
Degradation Temperature ◽  
Hyperbranched Polyurethane

A series of different generation hyperbranched polyurethane(HBPU) was synthesized based on the raw materials of isophorone diisocyanate(IPDI) and diethanolamine(DEOA). Their structure, thermal degradation mechanism and glass transition temperature(Tg) were characterized by fourier transform infrared spectroscopy(FTIR), nuclear magnetic resonance spectroscopy(NMR), thermal gravimetric analysis(TGA) and differential scanning calorimetry(DSC). The results showed that: the yield of each generation HBPU was up to 90%, different generation HBPU had almost the same initial degradation temperature(about at 200°C) and they all had two decomposition platforms; with the increase of generation, Tg increased from 107.2°C to 132.1°C. The gloss and hardness of the HBPU coatings were significantly improved.

Synthesis and thermal stability studies of polyaniline/silver nanocomposite based on reduction of silver ions using polyaniline

2011 ◽  
Vol 23 (7) ◽  
pp. 513-517 ◽  
Author(s):  
Mohsen Ghorbani ◽  
Mohammad Soleimani Lashkenari ◽  
Hossein Eisazadeh
Keyword(s):  
Thermal Stability ◽  
Chemical Structure ◽  
Aqueous Media ◽  
Silver Ions ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Stability Studies ◽  
Scanning Calorimetry ◽  
Chemical Polymerization ◽  
Silver Nanocomposite

This study investigated the preparation and properties of polyaniline/silver (PAn/Ag2O) nanocomposite in aqueous media by chemical polymerization of aniline in the presence of ammonium peroxydisulphate as an oxidant. The products were investigated in terms of morphology, chemical structure, thermal stability and thermal degradation using scanning electron microscopy, Fourier transform infrared, thermal gravimetric analysis and differential scanning calorimetry, respectively. The results indicated that the properties of products were dependent on the nanocomposite structure.

Synthesis and characterization of diaminomaleonitrile-functionalized polystyrene grafts for application in pervaporation separation

2008 ◽  
Vol 62 (4) ◽  
Author(s):  
Hamada Abdel-Razik
Keyword(s):  
Chemical Structure ◽  
Thermal Characteristics ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Optimum Conditions ◽  
Scanning Calorimetry ◽  
Phenol Water ◽  
Pervaporation Separation ◽  
Thermal Stability Of

AbstractSynthesis, characterization and application of diaminomaleonitrile (DAMN)-functionalized polystyrene grafts were studied. Dibenzoyle peroxide (BP) was used as an initiator. Optimum conditions for grafting were found to be c(DAMN) = 0.5 M, c(BP) = 0.016 M, θ = 85 °C and t = 4 h. Water uptake of the polystyrene graft membranes was found to increase with the increase of the grafting yield. The chemical structure, thermal characteristics and thermal stability of the obtained membranes were investigated by means of FTIR spectroscopy, differential scanning calorimetry, and thermal gravimetric analysis. Polystyrene graft membrane with the degree of grafting of up to 96 % was found to be useful for the pervaporation separation of phenol/water mixtures.

Preparation of Two Novel Ionic Electroconductive Polyurethanes Functionalized with the Backbone of Ionic Liquid

2013 ◽  
Vol 668 ◽  
pp. 259-262
Author(s):  
Ding Jun Zhang ◽  
Chao Yun Qu ◽  
Yu Xian Chen
Keyword(s):  
Electrical Conductivity ◽  
Differential Scanning Calorimetry ◽  
Ionic Liquid ◽  
Surface Resistance ◽  
High Yield ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Facile Synthesis ◽  
Scanning Calorimetry ◽  
Structures And Properties

The facile synthesis of two new Ionic electroconductive polyurethanes with the framework of ionic liquids, i.e., PUR-T: synthesized with isocyanate TDI; PUR-H: synthesized with isocyanate HDL, are described. Their structures and properties were characterized by Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), Differential scanning calorimetry (DSC) and the surface resistance meter. The effects of the different kinds of isocyanate on electrical conductivity of PUR were also investigated. It was found that their electrical conductivity can be optimized by changing the reaction temperature. The PUR-H, which exhibits an electrical conductivity of 1.0×104 Ω surface resistance, could be obtained in high yield, up to 65% at 90 oC for 12h.

Crosslinking of Polyamide 6 by Reactive Processing

2015 ◽  
Vol 815 ◽  
pp. 576-582 ◽  
Author(s):  
Tao Yu ◽  
Jian Sheng Chen ◽  
Fu Mei Wu ◽  
Jens Rocks
Keyword(s):  
Polyamide 6 ◽  
Mechanical Tests ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Reactive Processing ◽  
Reactive Blending ◽  
Scanning Calorimetry ◽  
Engineering Plastics ◽  
Chemical Coupling ◽  
Positive Effect

In order to check the feasibility of crosslinking engineering plastics through chemical coupling, reactive blending of polyamide 6 (PA6) was performed with various amounts of a multi-functional epoxide named as Joncryl ADR®4370s. The formation of cross-linked structure in ADR modified PA6 was clearly verified by utilizing dynamic rheological technique. The thermal properties of modified PA6 were compared with that of pristine nylon by combination of differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Mechanical tests were also carried out and the results showed that ADR had a positive effect on improving tensile properties of polyamide.

scholarly journals Methodology of Corrosion Testing of Nuclear and Fusion Reactors Materials Using TGA/DSC and MS Complex Techniques

2019 ◽  
pp. 35 ◽  
Author(s):  
Yu.V. Ponkratov ◽  
V.S. Bochkov ◽  
K.K. Samarkhanov ◽  
I.S. Karambayeva ◽  
S.K. Askerbekov
Keyword(s):  
Corrosion Resistance ◽  
Fission Products ◽  
Structural Materials ◽  
Gas Mixtures ◽  
Fusion Reactors ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Active Elements ◽  
Different Gases

The behavior of structural materials of nuclear and fusion reactors during operation largely determines their safe and economical work. Structural materials of nuclear and fusion reactors are operating under conditions of interaction with various chemical active elements (gases, vapor-gas mixtures, fission products, etc.) in a wide temperature range; they are subject to high requirements in terms of their thermal and corrosion resistance. This paper presents the new methodology of complex studies on structural materials corrosion resistance of nuclear and fusion reactors with different gases and vapor-gas mixtures by thermal-gravimetric analysis (TGA), differential-scanning calorimetry (DSC) and mass spectrometry (MS) methods simultaneously.

Preparation and Ferroelectric Properties of (Ba0.7Ca0.3)TiO3 Ceramics

2010 ◽  
Vol 148-149 ◽  
pp. 1016-1020
Author(s):  
Li Ren Han ◽  
Wei Guo Fu ◽  
Xiang Yun Deng ◽  
Xiao Fen Guan ◽  
Zhong Wen Tan ◽  
...  
Keyword(s):  
Ferroelectric Properties ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Structural Evolution ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Maximum Dielectric Constant ◽  
Gel Technique ◽  
Curie Temperature Tc

(Ba0.7Ca0.3)TiO3 (BCT) powders and ceramics have been prepared by sol-gel technique. Structural evolution of the BCT dry gels are investigated by thermal gravimetric analysis–differential scanning calorimetry. It is found that BCT crystallites can be formed before 800 . Well-sintered samples are synthesized at 1260 for 2h. The crystal structure of the BCT powders is studied by XRD and ferroelectric properties of the ceramics are characterized by TF analyzer 2000. The Curie temperature Tc of the BCT ceramics is at about 125 . The maximum dielectric constant (εr) reaches about 4851 at 125 and hysteresis loops are measured with the temperature range from 25 to 150 .

Pad Degradation During CMP Process: Effect of Soak in Slurry and Water on Thermal and Mechanical Properties of the CMP Pads

2003 ◽  
Vol 767 ◽  
Author(s):  
A. Tregub ◽  
G. Ng ◽  
M. Moinpour
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Thermal Gravimetric Analysis ◽  
Mechanical Analysis ◽  
Gravimetric Analysis ◽  
Thermal And Mechanical Properties ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Thermal Mechanical Analysis

AbstractSoak of polyurethane-based CMP pads in tungsten slurry and de-ionized water and its effect on retention of thermal and mechanical properties of the pads was studied using Dynamic Mechanical Analysis (DMA), Thermal Mechanical Analysis (TMA), Thermal Gravimetric Analysis (TGA), and Modulated Differential Scanning Calorimetry (MDSC). Simultaneous cross-linking and plastisizing due to soak were established using DMA and MDSC analysis. The stable operating temperature range and its dependence on soak time were determined using TMA analysis. Substantial difference in diffusion behavior of the “soft” and “hard” pads was discovered: diffusion into the hard pads followed Fickian law [1], while diffusion into the multi-layer soft pads was dominated by the fast filling of the highly porous pad surface with liquid.During a traditional CMP process, which involves application of polishing pads and slurry, the pad properties can be substantially and irreversibly changed as the result of slurry/rinse water absorption.The retention of the pad properties after exposure was monitored using such thermal and mechanical techniques, as Thermal Mechanical Analysis (TMA), Dynamical Mechanical Analysis (DMA), Modulated Differential Scanning Calorimetry (MDSC), Thermal Gravimetric Analysis (TGA).

Effect of functional nitrile groups on curing behaviors and thermal properties of epoxy resins as advanced matrix materials

2012 ◽  
Vol 19 (4) ◽  
pp. 347-350 ◽  
Author(s):  
Heng Guo ◽  
Jiandong Zhang ◽  
Zhiran Chen ◽  
Junji Wei ◽  
Rui Zhao ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Epoxy Resins ◽  
Side Chain ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
Rheological Analysis ◽  
Glass Transition Temperatures ◽  
Epoxy Blends

AbstractThis paper reports the preparation of the amine/epoxy blends with various amines such as 4,4′-diaminodiphenylsulfone (DDS), one nitrile side chain-containing diamine (BDB), and phthalonitrile-containing amine (APN). Differential scanning calorimetry (DSC), rheological analysis, and thermal gravimetric analysis (TGA) were used to evaluate the curing behaviors and thermal properties of amine/epoxy blends with the effect of functional nitrile groups of amines. Interestingly, an amine/epoxy blend exhibited double curing reactions. The cured epoxy copolymers exhibited high glass transition temperatures (>220°C) and excellent thermal stabilities having 5% weight loss temperature in the range of 375°C to 383°C.

scholarly journals Effect of Immobilization Methods on the Production of Polyethylene-cellulose Biocomposites via Ethylene Polymerization with Metallocene/MAO Catalyst

2020 ◽  
Vol 15 (3) ◽  
pp. 752-764
Author(s):  
Praonapa Tumawong ◽  
Ekrachan Chaichana ◽  
Bunjerd Jongsomjit
Keyword(s):  
Catalytic Activity ◽  
Ethylene Polymerization ◽  
Heterogeneous System ◽  
Metallocene Catalyst ◽  
Homogeneous System ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Active Components ◽  
Scanning Calorimetry ◽  
X Ray

Polyethylene-cellulose biocomposites were synthesized here via the ethylene polymerization with metallocene as a catalyst along with methylaluminoxane (MAO) as a cocatalyst. The immobilization method in which the catalyst or cocatalyst is fixed onto the catalytic filler (cellulose) can be classified into 3 methods according to the active components fixed onto the filler surface: 1) only metallocene catalyst (Cellulose/Zr), 2) only MAO cocatalyst (Cellulose/MAO) and 3) mixture of metallocene and MAO (Cellulose/(Zr+MAO)). It was found that the different immobilization methods or different fillers altered the properties of the obtained composites and also the catalytic activity of the polymerization systems. It was found that Cellulose/MAO provided the highest catalytic activity among all fillers due to a crown-alumoxane complex, which caused the heterogeneous system with this filler behaved similarly to the homogeneous system. The different fillers also produced the biocomposites with some different properties such as crystallinity which Cellulose/Zr provided the highest crystallinity compared with other fillers as observed by a thermal gravimetric analysis-differential scanning calorimetry (TGA-DSC). Nevertheless, the main crystal structure indicated to the typical polyethylene was still observed for all obtained biocomposites with different fillers as observed by an X-ray diffractometer (XRD).  Copyright © 2020 BCREC Group. All rights reserved

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