Epoxy Cured with Anhydride Terminated Polydimethylsiloxane: Cure Kinetics and Thermal Properties

2011 ◽  
Vol 415-417 ◽  
pp. 261-264
Author(s):  
Yuan Ren ◽  
Zheng Xi ◽  
Wen Jun Gan ◽  
Liang Zhang ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermal Properties ◽  
Succinic Anhydride ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Scanning Calorimetry ◽  
Thermogravimetric Analyses ◽  
Isothermal Measurements ◽  
Thermal Stability Of

A siloxane-containing dianhydride, succinic anhydride terminated polydimethylsiloxane (DMS-Z21) was selected to cure diglycidyl ether of bisphenol-A based epoxy resin (DGEBA). The cure kinetics and thermal properties were investigated by nonisothermal and isothermal differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA), respectively. The activation energy (Ea) of the curing reaction was obtained based on the methods of Kissinger and isothermal measurements. The results of the thermogravimetric analyses of the DGEBA/DMS-Z21 system showed that the thermal stability of the DGEBA/DMS-Z21 system was slightly higher than the DGEBA/MeTHPA system.

scholarly journals Thermal stability of segmented polyurethane elastomers reinforced by clay particles

2009 ◽  
Vol 63 (6) ◽  
pp. 621-628 ◽  
Author(s):  
Jelena Pavlicevic ◽  
Jaroslava Budinski-Simendic ◽  
Mészáros Szécsényi ◽  
Nada Lazic ◽  
Milena Spirkova ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Chain Extender ◽  
Hexamethylene Diisocyanate ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Polyurethane Elastomers ◽  
Oh Groups ◽  
Clay Nanoparticles ◽  
Thermal Stability Of

The aim of this work was to determine the influence of clay nanoparticles on thermal properties of segmented polyurethanes based on hexamethylene- diisocyanate, aliphatic polycarbonate diol and 1,4-butanediol as chain extender. The organically modified particles of montmorillonite and bentonite were used as reinforcing fillers. The structure of elastomeric materials was varied either by diol type or chain extender content. The ratio of OH groups from diol and chain extender (R) was either 1 or 10. Thermal properties of prepared materials were determined using modulated differential scanning calorimetry (MDSC). Thermal stability of obtained elastomers has been studied by simultaneously thermogravimetry coupled with DSC. The glass transition temperature, Tg, of soft segments for all investigated samples was about -33?C. On the basis of DTG results, it was concluded that obtained materials were very stable up to 300?C.

Preparation and Thermal Properties of Polybenzoxazine/TiC Hybrids

2014 ◽  
Vol 887-888 ◽  
pp. 49-52 ◽  
Author(s):  
Noureddine Ramdani ◽  
Jun Wang ◽  
Wen Bin Liu
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
High Performance ◽  
Phenolic Resin ◽  
Scanning Calorimetry ◽  
New Class ◽  
Solution Blending ◽  
Tic Nanoparticles ◽  
Thermal Stability Of

In this work, typical polybenzoxazine, as new class of phenolic resin, has been used as a matrix for preparing a series of high performance hybrid materials using various amounts of titanium carbide (TiC) ranging between 0-10 wt% as fillers, via a solution blending technique. The thermal properties of bisphenol A-aniline base benzoxazine monomers (BA-a) and TiC mixtures have been studied by differential scanning calorimetry (DSC). The thermal stability of their cured hybrids has been tested by means of thermogravimetric analysis (TGA). The result showed that the glass transition temperature of the prepared composites increased with increasing the amount of TiC to reach a higher value at 194°C. Also, the incorporation of TiC nanoparticles has considerably improved the thermal stability of the hybrids including the char yield which increase by 50 % at 10 wt% TiC content.

scholarly journals Surface Modification of Cellulose Nanocrystals with Succinic Anhydride

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 866 ◽  
Author(s):  
Agnieszka Leszczyńska ◽  
Paulina Radzik ◽  
Ewa Szefer ◽  
Matej Mičušík ◽  
Mária Omastová ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Surface Modification ◽  
Thermal Properties ◽  
Reaction Time ◽  
Cellulose Nanocrystals ◽  
Succinic Anhydride ◽  
Molar Ratio ◽  
Hydroxyl Groups ◽  
Degree Of Esterification ◽  
Thermal Stability Of

The surface modification of cellulose nanocrystals (CNC) is a key intermediate step in the development of new functionalities and the tailoring of nanomaterial properties for specific applications. In the area of polymeric nanocomposites, apart from good interfacial adhesion, the high thermal stability of cellulose nanomaterial is vitally required for the stable processing and improvement of material properties. In this respect, the heterogeneous esterification of CNC with succinic anhydride was investigated in this work in order to obtain CNC with optimised surface and thermal properties. The influence of reaction parameters, such as time, temperature, and molar ratio of reagents, on the structure, morphology and thermal properties, were systematically studied over a wide range of values by DLS, FTIR, XPS, WAXD, SEM and TGA methods. It was found that the degree of surface substitution of CNC increased with the molar ratio of succinic anhydride to cellulose hydroxyl groups (SA:OH), as well as the reaction time, whilst the temperature of reaction showed a moderate effect on the degree of esterification in the range of 70–110 °C. The studies on the thermal stability of modified nanoparticles indicated that there is a critical extent of surface esterification below which only a slight decrease of the initial temperature of degradation was observed in pyrolytic and oxidative atmospheres. A significant reduction of CNC thermal stability was observed only for the longest reaction time (240 min) and the highest molar ratio of SA:OH. This illustrates the possibility of manufacturing thermally stable, succinylated, CNC by controlling the reaction conditions and the degree of esterification.

Effect of alkali treatment on the thermal properties of wheat straw fiber reinforced epoxy composites

2016 ◽  
Vol 51 (3) ◽  
pp. 323-331 ◽  
Author(s):  
Varun Mittal ◽  
Shishir Sinha
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Wheat Straw ◽  
Fiber Composite ◽  
Alkali Treatment ◽  
Epoxy Composites ◽  
Scanning Calorimetry ◽  
Ftir Studies ◽  
Four Levels ◽  
Thermal Stability Of

This paper focuses on the study of the effect of fiber content and alkali treatment on the thermal properties of wheat straw epoxy composite. Four levels of fiber loading (10, 20, 30, and 40 wt%) of wheat straw and three levels of alkali treatment (1, 3, and 5%) were considered and merged into epoxy composites. The composites were prepared by hand layup technique. The thermal stability of the components was studied by thermogravimetric analysis and differential scanning calorimetry, as well as by the differential thermogravimetric. The experimental results show that the thermal stability of the composites prepared from 3% alkali-treated fibers is superior as compared to the untreated and another level of alkali-treated fiber composite. This is mainly due to the efficient fiber–matrix adhesion in the alkali-treated wheat straw epoxy composites. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) studies were carried out to evaluate the microstructure and composition of wheat straw fiber/epoxy composites, respectively.

Effect of chemical treatment on thermal properties of bagasse fiber-reinforced epoxy composite

2017 ◽  
Vol 24 (2) ◽  
pp. 237-243 ◽  
Author(s):  
Varun Mittal ◽  
Shishir Sinha
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Chemical Treatment ◽  
Epoxy Composite ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Chemical Treatments ◽  
Bagasse Fiber ◽  
Thermal Stability Of

AbstractThe present paper deals with a study of the thermal properties of bagasse fiber (BF)-reinforced epoxy composites. BFs are subjected to untreated and chemical treatments with 1% sodium hydroxide followed by 1% acrylic acid at ambient temperature before the composites are made. The thermal stability of the components was studied by thermogravimetric analysis and differential scanning calorimetry, as well as by differential thermal gravimetric analysis. Thermal analysis results of untreated BF-reinforced epoxy composite were compared with treated BF-reinforced epoxy composite. The chemical treatment of BF induces reasonable changes in the thermal stability of the polymer composites.

scholarly journals Low-pickle Processing of Leather: Assessment of Leather Tanning Quality by Methods of Thermal Analysis

2020 ◽  
Vol 26 (3) ◽  
pp. 333-336
Author(s):  
Virgilijus VALEIKA
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Oxalic Acid Solution ◽  
Additional Treatment ◽  
High Tensile Strength ◽  
Scanning Calorimetry ◽  
Shrinkage Temperature ◽  
Thermogravimetric Analyses ◽  
Thermal Stability Of

Pelt obtained by deliming with peracetic acid can be chromed after additional treatment with sodium chloride or oxalic acid solution, or directly tanned using synthetic tannins. The results of differential scanning calorimetry and thermogravimetric analyses have suggested that any tanning increases thermal stability of leather collagen. The produced chrome-free leather, despite its high tensile strength, is not characterized by high shrinkage temperature what indicates insufficient thermal stability of such leather. This fact contradicts the results of differential scanning calorimetry and thermogravimetric analyses results which show the high thermal stability of the chrome-free leather. It has been concluded that scanning calorimetry and thermogravimetric analyses are not sufficient for the appropriate assessment of leather obtained by the methods of various tanning, and the conclusions about changes in leather structure and quality of leather can not be drawn only upon results of the mentioned analyses.

Thermal properties and thermal stability of polypropylene composites filled with graphene nanoplatelets

2017 ◽  
Vol 31 (2) ◽  
pp. 246-264 ◽  
Author(s):  
JZ Liang ◽  
JZ Wang ◽  
Gary CP Tsui ◽  
CY Tang
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Weight Fraction ◽  
Decomposition Temperature ◽  
Graphene Nanoplatelets ◽  
Filler Concentration ◽  
Scanning Calorimetry ◽  
Lateral Dimension ◽  
Polypropylene Composites ◽  
Thermal Stability Of

The thermal properties and thermal stability of polypropylene (PP) composites separately filled with graphene nanoplatelets (GNPs) with three different sizes were measured using a differential scanning calorimetry and a thermal gravimetric analyser. The results showed that the values of the melting temperature of the composites were higher than that of the unfilled PP; the thermal stability increased with increasing the weight fraction and lateral dimension of GNPs in the case of low filler concentration, while the effect of the GNPs thickness on the thermal stability was insignificant; the onset decomposition temperature increased with increasing the GNPs lateral dimension, while the maximum thermal decomposition rate increased first and then decreased with increasing the GNPs weight fraction. The thermal stability improvement should be attributed to the sheet barrier function of the GNPs.

Dynamic Mechanical Properties of Epoxy Resin with Multifunctional Polyamine Curing Agent

2015 ◽  
Vol 744-746 ◽  
pp. 1374-1377
Author(s):  
Xi Wang
Keyword(s):  
Thermal Stability ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Diglycidyl Ether ◽  
Curing Agent ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Dynamic Mechanical ◽  
Glass Relaxation ◽  
Thermal Stability Of

A nonlinear multifunctional polyamine N,N,N’,N’-tetra (3-aminopropyl)-1,6-diamino-hexane (TADH), was prepared and employed as a novel hardener for diglycidyl ether of bisphenol A (DGEBA). Nonisothermal reactions of DGEBA/TADH were systematically investigated with differential scanning calorimetry (DSC). In addition, analysis of thermal stability of the cured DGEBA/TADH with thermogravimetric analysis (TGA) revealed that it possessed quite good thermal stability and increased residual char content at 600◦C in nitrogen. Furthermore, dynamic mechanical analysis (DMA) of the DGEBA/TADH network showed its relaxations were characterized by localized motions of hydroxyl ether segments and cooperative motions of whole network chains (glass relaxation) at different temperature regions.

Thermal and Morphological Properties of Chitosan Filled Epoxy

2014 ◽  
Vol 627 ◽  
pp. 12-17
Author(s):  
Britto Satheesh ◽  
Kim Yeow Tshai ◽  
Nick Warrior
Keyword(s):  
Thermal Stability ◽  
Diglycidyl Ether ◽  
Morphological Properties ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Weight Percentage ◽  
Force Microscopy ◽  
Atomic Force ◽  
Thermal Stability Of

This paper investigates the effects of polysaccharide additive agent on the morphological and thermal properties of thermosetting polymer. The weight percentage (wt%) of Diglycidyl Ether of Bisphenol A (DGEBA) epoxy resin to Hexamethylenediamine (HMDA) hardener were kept constant while a varyingwt% of chitosan, ranging from 0 to 10wt% was introduced. The chitosan filled epoxy hardener mixture was allowed to cure at 40°C for a period of 12 hours. Dynamic Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA) were conducted on the specimens to analyse the effects of chitosan loading on thermal stability and transition temperature while Atomic Force Microscopy (AFM) was used to investigate the changes to its morphological property. At chitosan loading of 2.5wt% and below, good dispersion of the additive was observed. Apparent agglomeration and phase separation were formed when chitosan content increases above 7.5wt%. The formation of bulky chitosan agglomeration was found capable of enhancing the thermal stability of the thermoset polymer. The diamine acted as the co-reactants with DGEBA as well as spacer which decrease the effect of material brittleness due to addition of chitosan.

Estimation of Cure and Thermal Degradation Kinetics of Epoxy/Organoclay Nanocomposite

2010 ◽  
Vol 123-125 ◽  
pp. 667-670 ◽  
Author(s):  
Jae Young Lee ◽  
Bum Choul Choi ◽  
Hong Ki Lee
Keyword(s):  
Activation Energy ◽  
Thermal Degradation ◽  
Epoxy Matrix ◽  
Degradation Kinetics ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Kinetics Of

Polymer nanocomposite was synthesized through the intercalation and exfoliation of organoclay in an epoxy matrix. The epoxy matrix was composed of diglycidyl ether of bisphenol A (DGEBA, epoxy base resin), 4,4'-methylene dianiline (MDA, curing agent) and malononitrile (MN, chain extender) and organoclay was prepared by treating the montmorillonite with octadecyltrimethylammonium bromide (ODTMA). The intercalation of the organoclay was estimated by wide angle X-ray diffraction (WAXD) and transmission electron microscope (TEM) analyses. In order to measure the cure rate of DGEBA/MDA (30 phr)/MN (5 phr)/Organoclay (5 phr), differential scanning calorimetry (DSC) analysis were performed at the heating rates of 5, 10, 15 and 20 oC/min, and the data was interpreted by Kissinger equation. Thermal degradation kinetics of the epoxy nanocomposite was also studied by thermogravimetric analysis (TGA). The epoxy sample was decomposed in the TGA furnace at the heating rates of 5, 10, 15 and 20 oC/min with nitrogen atmosphere of 50 ml/min. The TGA data was introduced to the Ozawa equation and the degradation activation energy was calculated according to the degradation ratio. The activation energy for cure kinetics was 43.3 kJ/mol and that for thermal degradation was 171.5 kJ/mol.

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