scholarly journals Dielectric spectroscopy of diglycidyl ether of bisphenol-A at glass transition temperature

2012 ◽  
Vol 04 (02) ◽  
pp. 136-141
Author(s):  
Soheil Sharifi
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Bisphenol A ◽  
Dielectric Spectroscopy ◽  
Diglycidyl Ether

scholarly journals Studies on the Modification of Commercial Bisphenol-A-Based Epoxy Resin Using Different Multifunctional Epoxy Systems

2021 ◽  
Vol 2 (2) ◽  
pp. 419-430
Author(s):  
Ankur Bajpai ◽  
James R. Davidson ◽  
Colin Robert
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Tensile Fracture ◽  
Chemical Structures ◽  
Amino Phenol ◽  
Epoxy Systems

The tensile fracture mechanics and thermo-mechanical properties of mixtures composed of two kinds of epoxy resins of different chemical structures and functional groups were studied. The base resin was a bi-functional epoxy resin based on diglycidyl ether of bisphenol-A (DGEBA) and the other resins were (a) distilled triglycidylether of meta-amino phenol (b) 1, 6–naphthalene di epoxy and (c) fluorene di epoxy. This research shows that a small number of multifunctional epoxy systems, both di- and tri-functional, can significantly increase tensile strength (14%) over neat DGEBA while having no negative impact on other mechanical properties including glass transition temperature and elastic modulus. In fact, when compared to unmodified DGEBA, the tri-functional epoxy shows a slight increase (5%) in glass transition temperature at 10 wt.% concentration. The enhanced crosslinking of DGEBA (90 wt.%)/distilled triglycidylether of meta-amino phenol (10 wt.%) blends may be the possible reason for the improved glass transition. Finally, the influence of strain rate, temperature and moisture were investigated for both the neat DGEBA and the best performing modified system. The neat DGEBA was steadily outperformed by its modified counterpart in every condition.

scholarly journals Hydrophobically Modified Isosorbide Dimethacrylates as a Bisphenol-A (BPA)-Free Dental Filling Material

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2139
Author(s):  
Bilal Marie ◽  
Raymond Clark ◽  
Tim Gillece ◽  
Seher Ozkan ◽  
Michael Jaffe ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Flexural Strength ◽  
Bisphenol A ◽  
Water Sorption ◽  
Triethylene Glycol ◽  
Filling Material ◽  
Hydrophobically Modified ◽  
Free Replacement

A series of bio-based hydrophobically modified isosorbide dimethacrylates, with para-, meta-, and ortho- benzoate aromatic spacers (ISBGBMA), are synthesized, characterized, and evaluated as potential dental restorative resins. The new monomers, isosorbide 2,5-bis(4-glyceryloxybenzoate) dimethacrylate (ISB4GBMA), isosorbide 2,5-bis(3-glyceryloxybenzoate) dimethacrylate (ISB3GBMA), and isosorbide 2,5-bis(2-glyceryloxybenzoate) dimethacrylate (ISB2GBMA), are mixed with triethylene glycol dimethacrylate (TEGDMA) and photopolymerized. The resulting polymers are evaluated for the degree of monomeric conversion, polymerization shrinkage, water sorption, glass transition temperature, and flexural strength. Isosorbide glycerolate dimethacrylate (ISDGMA) is synthesized, and Bisphenol A glycerolate dimethacrylate (BisGMA) is prepared, and both are evaluated as a reference. Poly(ISBGBMA/TEGDMA) series shows lower water sorption (39–44 µg/mm3) over Poly(ISDGMA/TEGDMA) (73 µg/mm3) but higher than Poly(BisGMA/TEGDMA) (26 µg/mm3). Flexural strength is higher for Poly(ISBGBMA/TEGDMA) series (37–45 MPa) over Poly(ISDGMA/TEGDMA) (10 MPa) and less than Poly(BisGMA/TEGDMA) (53 MPa) after immersion in phosphate-buffered saline (DPBS) for 24 h. Poly(ISB2GBMA/TEGDMA) has the highest glass transition temperature at 85 °C, and its monomeric mixture has the lowest viscosity at 0.62 Pa·s, among the (ISBGBMA/TEGDMA) polymers and monomer mixtures. Collectively, this data suggests that the ortho ISBGBMA monomer is a potential bio-based, BPA-free replacement for BisGMA, and could be the focus for future study.

Influence of Carbon Nanotube Aspect Ratio on Glass Transition Temperature of Polymers: A Molecular Dynamics Simulation Study

2015 ◽  
Vol 817 ◽  
pp. 797-802 ◽  
Author(s):  
Cai Jiang ◽  
Jian Wei Zhang ◽  
Shao Feng Lin ◽  
Su Ju ◽  
Da Zhi Jiang
Keyword(s):  
Molecular Dynamics ◽  
Glass Transition ◽  
Carbon Nanotube ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Aspect Ratio ◽  
Epoxy Resin ◽  
Md Simulations ◽  
Diglycidyl Ether ◽  
Dynamics Simulation

Molecular dynamics (MD) simulations on three single walled carbon nanotube (SWCNT) reinforced epoxy resin composites were conducted to study the influence of SWCNT type on the glass transition temperature (Tg) of the composites. The composite matrix is cross-linked epoxy resin based on the epoxy monomers bisphenol A diglycidyl ether (DGEBA) cured by diaminodiphenylmethane (DDM). MD simulations of NPT (constant number of particles, constant pressure and constant temperature) dynamics were carried out to obtain density as a function of temperature for each composite system. The Tg was determined as the temperature corresponding to the discontinuity of plot slopes of the densityvsthe temperature. In order to understand the motion of polymer chain segments above and below the Tg, various energy components and the MSD at various temperatures of the composites were investigated and their roles played in the glass transition process were analyzed. The results show that the Tg of the composites increases with increasing aspect ratio of the embedded SWCNT

Curing, Thermal and Mechanical Properties of Liquid Crystalline p-SBPEPB/BPAER/DDE System

2011 ◽  
Vol 239-242 ◽  
pp. 3253-3256 ◽  
Author(s):  
Li Huo ◽  
Jun Gang Gao ◽  
Yong Gang Du
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Impact Strength ◽  
Bisphenol A ◽  
Liquid Crystalline ◽  
Curing Agent ◽  
Thermal And Mechanical Properties ◽  
Component System

The curing, thermal and mechanical properties of bi-component system for bisphenol A epoxy resin (BPAER) modified by liquid crystalline Sulfonyl bis(4,1-phenylene)bis[4-(2,3-epoxypro pyloxy)benzoate] (p-SBPEPB), with 4,4'-diaminodiphenyl ether (DDE) as a curing agent, were investigated. The effect of the different liquid crystalline contents and the heating rate on curing reaction was discussed. The results show that the curing peak temperature decreases, curing rate increases, the glass transition temperature (Tg)and impact strength all increase with adding of liquid crystalline p-SBPEPB when the content is not over 8wt%.

Processing and characterization of titanium dioxide composites from vegetable oil resource

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Mohamed Aboobucker Sithique
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Flexural Modulus ◽  
Thermo Gravimetric Analysis ◽  
Percent Level ◽  
Tensile Modulus ◽  
Renewable Resource ◽  
Diglycidyl Ether ◽  
Gravimetric Analysis

Abstract TiO2 filled bio-based composites were prepared from epoxidized soy bean oil and Diglycidyl ether of bisphenol-A, in which the nano TiO2 particles were dispersed using ultra sonication method. Composites prepared with 1, 3, 5 and 7 weight percent level (wt%) of TiO2 particles were characterized for their thermal properties such as glass transition temperature and degradation stability. Thermo gravimetric analysis (TGA) showed that thermal stability of the composites increases up to 5 wt% addition of TiO2; thereafter it follows a decreasing trend, since the increased amount of nano sized particles makes it difficult for dispersion. The glass transition temperature of the composites was improved considerably. Dynamic mechanical analysis (DMA) further confirms the restricted chain mobility of the composites upon reinforcement. The significant improvements in mechanical properties such as tensile strength, tensile modulus, flexural strength, flexural modulus, and impact strength were achieved on reinforcement. The wide angle X-ray diffraction (WAXD) studies show that the nanoparticles are exfoliated in the soy based epoxy matrix system. The morphological behavior of composites studied using scanning electron microscopy (SEM) reveals the compatibility between the matrix and nanoparticles. The results showed that adding nano sized TiO2 particles can improve the properties of thermal, mechanical, compatibility and water resistance of these renewable resource based epoxy matrices suitable for engineering applications.

Preparation of RPSL-02 Type Photosensitive Resin for Stereolithography Material and Investigation on its some Properties

2012 ◽  
Vol 252 ◽  
pp. 224-227
Author(s):  
Bi Wu Huang ◽  
Kuan Zhou ◽  
Chong Deng ◽  
Wei Qing Chen
Keyword(s):  
Weight Loss ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Bisphenol A ◽  
Raw Materials ◽  
Triethylene Glycol ◽  
Divinyl Ether ◽  
Photosensitive Resin

RPSL-02 type photosensitive resin for stereolithography material was prepared with 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate (UVR 6110), bisphenol A type epoxy diacrylate (EA-612), trimethyolpropane triacrylate (TMPTA), polycaprolactone polyol (polyol-0301), triethylene glycol divinyl ether (DVE-3), benzil dimethyl ketal (Irgacure651) and a mixture of triarylsulfonium hexafluoroantimonate salts (UVI-6976) as raw materials. Some properties of the photosensitive resin were investigated. The viscosity of the photosensitive resin at 30°C was 395mPa.S, The glass transition temperature (Tg ) of the UV-cured specimen was 52°C, and the weight loss of the UV-cured specimen at 200°C was less than 5%. The photosensitive resin and its UV-cured specimen were also characterized by infrared (IR).

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