Curing Behavior of Epoxy Resin Mixed with Epoxypropoxypropyl Terminated Polydimethylsiloxane

2013 ◽  
Vol 677 ◽  
pp. 197-200
Author(s):  
Zheng Xi ◽  
Jin Dian Ding ◽  
Wen Jun Gan ◽  
Zhao Zhang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Bisphenol A ◽  
Microphase Separation ◽  
Curing Kinetics ◽  
Diglycidyl Ether ◽  
Separation Mechanism ◽  
Scanning Calorimetry ◽  
Modified Epoxy ◽  
Epoxy Systems ◽  
Electronic Microscope

Diglycidyl ether of bisphenol A (DGEBA) and epoxypropoxypropyl terminated polydimethylsiloxane (ETDMS) were mixed in different proportion. The morphology of ETDMS modified epoxy systems was observed by scanning electronic microscope (SEM). Curing kinetics was also studied by differential scanning calorimetry (DSC). It was suggested that the formation of the microstructures followed reaction-induced microphase separation mechanism.

scholarly journals PPG-Terminated Tetra-Carbamates as the Toughening Additive for Bis-A Epoxy Resin

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1522
Author(s):  
Ming Zhang ◽  
Mingqing Chen ◽  
Zhongbin Ni
Keyword(s):  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Microphase Separation ◽  
Intramolecular Interactions ◽  
Hexamethylene Diisocyanate ◽  
Separation Mechanism ◽  
Toughening Mechanism ◽  
The Impact ◽  
Modified Epoxy ◽  
Epoxy Systems

We synthesized PPG-terminated tetra-carbamates as a new toughening additive for epoxy thermosets through facile addition reaction of hexamethylene diisocyanate (HDI) with poly(tetra-methylene glycols) (PTMG) and poly(propylene glycols) (PPG). The effects of prepared tetra-carbamates on the rheological behavior of neat epoxy resin were studied along with the various cured properties of their modified epoxy systems. Four carbamate groups (–NHCOO–) endow the prepared additives not only with good intramolecular interactions, but also with optimal intermolecular interactions with epoxy polymers. This results in the suitable miscibility of the additives with the epoxy matrix for the formation of the typical biphasic structure of microparticles dispersed in the epoxy matrix via polymerization-induced microphase separation. The impact strength and critical stress concentration factor (KIC) of cured modified epoxy systems with the additives are significantly higher than those of unmodified epoxy systems, without sacrificing the processability (Tg) and flexural strength. The toughening mechanism is understood as a synergism combination among the phase separation mechanism, the in situ homogeneous toughening mechanism, and the particle cavitation mechanism.

scholarly journals Novel Bio-Based Epoxy Thermosets Based on Triglycidyl Phloroglucinol Prepared by Thiol-Epoxy Reaction

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 337 ◽  
Author(s):  
Dailyn Guzmán ◽  
David Santiago ◽  
Àngels Serra ◽  
Francesc Ferrando
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Bisphenol A ◽  
Diglycidyl Ether ◽  
Scanning Calorimetry ◽  
High Transparency ◽  
Epoxy Curing ◽  
Curing Agents

The pure trifunctional glycidyl monomer from phloroglucinol (3EPO-Ph) was synthesized and used as feedstock in the preparation of novel bio-based thermosets by thiol-epoxy curing. The monomer was crosslinked with different commercially available thiols: tetrafunctional thiol (PETMP), trifunctional thiol (TTMP) and an aromatic dithiol (TBBT) as curing agents in the presence of a base. As catalyst, two different commercial catalysts: LC-80 and 4-(N,N-dimethylamino) pyridine (DMAP) and a synthetic catalyst, imidazolium tetraphenylborate (base generator, BG) were employed. The curing of the reactive mixtures was studied by using DSC and the obtained materials by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). The results revealed that only the formulations catalyzed by BG showed a latent character. Already prepared thermosetting materials showed excellent thermal, thermomechanical and mechanical properties, with a high transparency. In addition to that, when compared with the diglycidyl ether of bisphenol A (DGEBA)/PETMP material, the thermosets prepared from the triglycidyl derivative of phloroglucinol have better final characteristics and therefore this derivative can be considered as a partial or total renewable substitute of DGEBA in technological applications.

scholarly journals Kinetic Analysis of the Curing of a Partially Biobased Epoxy Resin Using Dynamic Differential Scanning Calorimetry

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 391 ◽  
Author(s):  
Diego Lascano ◽  
Luis Quiles-Carrillo ◽  
Rafael Balart ◽  
Teodomiro Boronat ◽  
Nestor Montanes
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Epoxy Resins ◽  
Curing Kinetics ◽  
Reaction Model ◽  
Diglycidyl Ether ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Model Free

This research presents a cure kinetics study of an epoxy system consisting of a partially bio-sourced resin based on diglycidyl ether of bisphenol A (DGEBA) with amine hardener and a biobased reactive diluent from plants representing 31 wt %. The kinetic study has been carried out using differential scanning calorimetry (DSC) under non-isothermal conditions at different heating rates. Integral and derivative isoconversional methods or model free kinetics (MFK) have been applied to the experimental data in order to evaluate the apparent activation energy, Ea, followed by the application of the appropriate reaction model. The bio-sourced system showed activation energy that is independent of the extent of conversion, with Ea values between 57 and 62 kJ·mol−1, corresponding to typical activation energies of conventional epoxy resins. The reaction model was studied by comparing the calculated y(α) and z(α) functions with standard master plot curves. A two-parameter autocatalytic kinetic model of Šesták–Berggren [SB(m,n)] was assessed as the most suitable reaction model to describe the curing kinetics of the epoxy resins studied since it showed an excellent agreement with the experimental data.

Study of the Cure of a Diglycidyl-Ether of Bisphenol-a (DGEBA) / Triethylenetetramine (TETA) Epoxy System by Non-Isothermal Differential Scanning Calorimetry (DSC)

2006 ◽  
Vol 514-516 ◽  
pp. 1094-1098
Author(s):  
Rosa Losada ◽  
José Luís Mier ◽  
Fernando Barbadillo ◽  
Ramón Artiaga ◽  
Angel Varela ◽  
...  
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Bisphenol A ◽  
Inert Atmosphere ◽  
Diglycidyl Ether ◽  
Exothermic Peak ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Reaction Heat ◽  
Marine Coatings

A diglycidyl-ether of bisphenol-A (DGEBA)/Triethylenetetramine (TETA) system was studied by non-isothermal differential scanning calorimetry (DSC) to establish its kinetics of cure. The DGEBA resin was Araldite GZ 601 X75 used in the marine coatings formulations. Previously, the optimum resin/hardener ratio was determined by the reaction heat measuring (.Hc) calculated from the curing exothermic peak. Tests at different heating rates (10, 15, 20, 25 and 30°C/min) under inert atmosphere were carried out in order to study the reaction kinetics. The activation energy of the cure (Ea) was obtained from these tests data by Borchardt-Daniels, autocatalytic, Duswalt and isoconversional Ozawa methods. Once the activation energy was determined, the master curves method was applied to find the kinetic model which best describes the measured DSC data. The Sestak-Berggren model SB (m,n) was found to be the most adequate for the system studied.

scholarly journals Nanocrystal, phase transformation and microstructure of Ni50Ti50 shape memory alloy

2018 ◽  
Vol 24 (02) ◽  
pp. 22-25
Author(s):  
Dovchinvanchig M ◽  
Chunwang Zhao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
One Step ◽  
Niti Matrix ◽  
Electronic Microscope

The nanocrystal, phase transformation and microstructure behavior of Ni50Ti50 shape memory alloy was investigated by scanning electronic microscope, X-ray diffraction and differential scanning calorimetry. The results showed that the microstructure of Ni-Ti binary alloy consists of the NiTi2 phase and the NiTi matrix phase. One-step phase transformation was observed alloy.

scholarly journals Preparation and Characterization of Green Epoxy Resin Composites and Its Use in Corrosion Resistance

2018 ◽  
Author(s):  
Abbas Hassan Faris
Keyword(s):  
Bisphenol A ◽  
Epoxy Resin ◽  
Electrolyte Solutions ◽  
Kraft Lignin ◽  
Diglycidyl Ether ◽  
Kraft Pulping ◽  
Palm Tree ◽  
Scanning Calorimetry ◽  
Ft Ir ◽  
Nano Titanium Dioxide

In this work, appropriate alternative for diglycidyl ether bisphenol A (DGEBA) was found to avoid the destructive effects of bisphenol A. Lignin, an aromatic compound from palm tree leaves, was used as a renewable material to synthesize a bio-based epoxy resin. Lignin extracted using Kraft pulping process. Kraft Lignin was epoxidized with epichlorohydrin in alkaline medium. Nano-titanium dioxide was used as filler with ratio of 10% to prepare the green epoxy composite. The structure of the Kraft lignin and lignin-based epoxy resin was proven via Infrared spectra (FT-IR) were recorded using solid KBr disk by testing Shimadzu (FT-IR-8300) spectrophotometer. The thermal properties of the curing process of lignin-based epoxy resin and composite were investigate using Differential scanning calorimetry (DSC) analysis. Potentiodynamic measurements data revealed that the anti-corrosion performance of the lignin based epoxy resin. The study demonstrates successful of epoxidation of Kraft lignin. In addition, lignin based eopxy resin showed effective inhibitor for carbon steel in 3.5 wt. % NaCl electrolyte solutions

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