The structural modification of epoxy resins by a liquid elastomer

1994 ◽  
Vol 6 (1) ◽  
pp. 71-81
Author(s):  
A Padma ◽  
R M V G K Rao ◽  
C Subramaniam
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Reaction Mechanism ◽  
Acrylic Acid ◽  
Epoxy Resins ◽  
Structural Modification ◽  
Scanning Calorimetry ◽  
Different Temperatures ◽  
Group Reaction ◽  
Diaminodiphenyl Methane

A carboxy terminated poly-n-(butyl acrylate, acrylic acid, acrylonitryl) (PNBA) terpolymer was used as a modifier for three high-functionality epoxy resins, (i) epoxy novolac, (ii) triglycidyl-4-aminophenol (TGPAP) and (iii) tetraglycidyl diaminodiphenyl methane (TGDDM), used as matrix materials in polymer composites. The resin and elastomer were reacted using different amine catalysts at different temperatures. The progress of the reaction between the epoxy resin and elastomer was studied extensively by Fourier transform infrared (FMR) spectroscopy and differential scanning calorimetry (psc). The results show that hydroxy esterification and etherification occurred during the epoxy-carboxy group reaction. The possible reaction mechanism involved is discussed on the basis of the results obtained.

scholarly journals Swelling properties of chitosan hydrogels

2004 ◽  
Vol 22 (1) ◽  
pp. 32 ◽  
Author(s):  
David R Rohindra ◽  
Ashveen V Nand ◽  
Jagjit R Khurma
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Glass Transition ◽  
Free Water ◽  
Scanning Calorimetry ◽  
Swelling Behaviour ◽  
Swelling Properties ◽  
Different Temperatures ◽  
Ft Ir ◽  
Chitosan Hydrogels

Chitosan hydrogels were prepared by crosslinking chitosan with glutaraldehyde. The swelling behaviour of the crosslinked and uncross-linked hydrogels was measured by swelling the gels in media of different pH and at different temperatures. The swelling behavior was observed to be dependent on pH, temperature and the degree of crosslinking. The gel films were characterized by Fourier transform Infrared spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC). The glass transition temperature (Tg) and the amount of free water in the hydrogels decreased with increasing crosslinking in the hydrogels.

Thermal Behavior of Epoxy Resins Cured with an Amine-Containing, Thermoplastic Poly(arylene Ether Sulphone)

1999 ◽  
Vol 19 (3) ◽  
pp. 161-174 ◽  
Author(s):  
Oriana Motta ◽  
Antonino Rocca ◽  
Valentina Siracusa ◽  
Domenico Acierno
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Behavior ◽  
Kinetic Parameters ◽  
Epoxy Resins ◽  
Curing Agent ◽  
Cure Process ◽  
Scanning Calorimetry ◽  
Arylene Ether ◽  
Diaminodiphenyl Methane ◽  
Residual Heat

Abstract In this paper we carried out the crosslinking of the tetraglycidyl-4,4′- diaminodiphenyl methane epoxy resin by using a reactive poly(arylene ether sulphone) as curing agent. Differential scanning calorimetry was used to derive the kinetic parameters of the reactions involved in the cure process and to evaluate the extent of the reaction as a function of time by measuring the total (ΔHr) and the residual heat(ΔHresid) of the resin at different curing times. A comparatively slower reaction was found to take place when the resin was cured with the poly(arylene ether sulphone) that when it was cured with the conventional curing agent 4,4′-diaminodiphenyl sulphone.

scholarly journals Fast Swelling Superabsorbent Hydrogels Starch Based Prepared by Gamma Radiation Techniques

2014 ◽  
Vol 14 (3) ◽  
pp. 246-252 ◽  
Author(s):  
Erizal Erizal ◽  
Dian Pribadi Perkasa ◽  
Basril Abbas ◽  
Sudirman Sudirman ◽  
Sulistioso G.S.
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Ionic Strength ◽  
Acrylic Acid ◽  
Irradiation Dose ◽  
Room Temperature ◽  
Scanning Calorimetry ◽  
Radiation Crosslinking ◽  
Infra Red ◽  
Short Time

Fast swelling hydrogels were synthesized from the mixture of acrylamide (AAM)-acrylic acid (AA)-starch (15:5:1 w/v) solution by radiation crosslinking with varying irradiation doses (7.5-12.5 kGy) at room temperature. The copolymers were characterizated by Fourier transform infra red spectroscopy (FTIR) and Differential scanning calorimetry (DSC). It was found that hydrogels showed superabsorbent properties with higher swelling capacities (~400 g/g) and reached at a very short time (3 min). There was no significance difference between the effect irradiation dose on swelling of hydrogels. The hydrogels were also found to sensitive to the ionic strength of medium. The FTIR spectra and thermogram DSC of hydrogels were confirmed the crosslinking occurs in the hydrogels.

scholarly journals Comparative thermal research on tetraazapentalene-derived heat-resistant energetic structures

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jing Zhou ◽  
Li Ding ◽  
Yong Zhu ◽  
Bozhou Wang ◽  
Xiangzhi Li ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Fourier Transform ◽  
Energetic Materials ◽  
Great Influence ◽  
Fourier Transform Infrared ◽  
Thermal Decomposition Mechanism ◽  
Scanning Calorimetry ◽  
In Situ Ftir Spectroscopy ◽  
Heat Resistant

AbstractOrganic inner salt structures are ideal backbones for heat-resistant energetic materials and systematic studies towards the thermal properties of energetic organic inner salt structures are crucial to their applications. Herein, we report a comparative thermal research of two energetic organic inner salts with different tetraazapentalene backbones. Detailed thermal decomposition behaviors and kinetics were investigated through differential scanning calorimetry and thermogravimetric analysis (DSC-TG) methods, showing that the thermal stability of the inner salts is higher than most of the traditional heat-resistant energetic materials. Further studies towards the thermal decomposition mechanism were carried out through condensed-phase thermolysis/Fourier-transform infrared (in-situ FTIR) spectroscopy and the combination of differential scanning calorimetry-thermogravimetry-mass spectrometry-Fourier-transform infrared spectroscopy (DSC-TG-MS-FTIR) techniques. The experiment and calculation results prove that the arrangement of the inner salt backbones has great influence on the thermal decompositions of the corresponding energetic materials. The weak N4-N5 bond in “y-” pattern tetraazapentalene backbone lead to early decomposition process and the “z-” pattern tetraazapentalene backbone exhibits more concentrated decomposition behaviors.

scholarly journals Conversion of palm oil to new sulfur-based polymer by inverse vulcanization

2021 ◽  
Vol 287 ◽  
pp. 02014
Author(s):  
Amin Abbasi ◽  
Mohamed Mahmoud Nasef ◽  
Wan Zaireen Nisa Yahya ◽  
Muhammad Moniruzzaman
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Thermogravimetric Analysis ◽  
Palm Oil ◽  
Elemental Sulfur ◽  
Molten State ◽  
Scanning Calorimetry ◽  
Environmental Friendly ◽  
Sulfur Containing

The conversion of palm oil into a sulfur-based polymer by copolymerization with sulfur powder at its molten state is herein reported. The obtained sulfur-containing polymer was characterized using Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to demonstrate the successful conversion. The disappearance of the peaks related to vinylic groups of oil together with the appearance of a peak representing C-H rocking vibrations in the vicinity of C-S bonds confirmed the copolymerization of sulfur with oil. TGA revealed that the polymers have thermal stability up to 230°C under nitrogen and the polymers leave 10% sulfur-rich ash. DSC proved that a small amount of elemental sulfur remained unreacted in the polymer, which showed amorphous and heavily crosslinked structure resembling thermosets. These copolymers are an environmental-friendly polymeric material promoting the utilization of the abundant sulfur while also adding value to palm oil.

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