scholarly journals Fully Biobased Epoxy Resins from Fatty Acids and Lignin

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1158 ◽  
Author(s):  
Pablo Ortiz ◽  
Richard Vendamme ◽  
Walter Eevers
Keyword(s):  
Epoxy Resin ◽  
Renewable Resources ◽  
Epoxy Resins ◽  
Linseed Oil ◽  
Tensile Tests ◽  
Present System ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Commodity Chemicals ◽  
Epoxidized Linseed Oil

The use of renewable resources for plastic production is an imperious need for the reduction of the carbon footprint and the transition towards a circular economy. With that goal in mind, fully biobased epoxy resins have been designed and prepared by combining epoxidized linseed oil, lignin, and a biobased diamine derived from fatty acid dimers. The aromatic structures in lignin provide hardness and strength to an otherwise flexible and breakable epoxy resin. The curing of the system was investigated by infrared spectroscopy and differential scanning calorimetry (DSC). The influence of the different components on the thermo-mechanical properties of the epoxy resins was analyzed by DSC, thermal gravimetric analysis (TGA), and tensile tests. As the content of lignin in the resin increases, so does the glass transition, the Young’s modulus, and the onset of thermal degradation. This correlation is non-linear, and the higher the percentage of lignin, the more pronounced the effect. All the components of the epoxy resin being commodity chemicals, the present system provides a realistic opportunity for the preparation of fully biorenewable resins at an industrial scale.

scholarly journals Kinetic Analysis of the Curing Process of Biobased Epoxy Resin from Epoxidized Linseed Oil by Dynamic Differential Scanning Calorimetry

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1279
Author(s):  
Diego Lascano ◽  
Alejandro Lerma-Canto ◽  
Vicent Fombuena ◽  
Rafael Balart ◽  
Nestor Montanes ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Linseed Oil ◽  
Single Step ◽  
Curing Process ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Step Process ◽  
Epoxidized Linseed Oil

The curing process of epoxy resin based on epoxidized linseed oil (ELO) is studied using dynamic differential scanning calorimetry (DSC) in order to determine the kinetic triplet (Ea, f(α) and A) at different heating rates. The apparent activation energy, Ea, has been calculated by several differential and integral isoconversional methods, namely Kissinger, Friedman, Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS) and Starink. All methods provide similar values of Ea (between 66 and 69 kJ/mol), and this shows independence versus the heating rate used. The epoxy resins crosslinking is characterized by a multi-step process. However, for the sake of the simplicity and to facilitate the understanding of the influence of the oxirane location on the curing kinetic, this can be assimilated to a single-step process. The reaction model has a high proportion of autocatalytic process, fulfilling that αM is between 0 and αp and αM < αp∞. Using as reference the model proposed by Šesták–Berggren, by obtaining two parameters (n and m) it is possible to obtain, on the one hand, the kinetic parameters and, on the other hand, a graphical comparison of the degree of conversion, α, versus temperature (T) at different heating rates with the average n and m values of this model. The good accuracy of the proposed model with regard to the actual values obtained by DSC gives consistency to the obtained parameters, thus suggesting the crosslinking of the ELO-based epoxy has apparent activation energies similar to other petroleum-derived epoxy resins.

scholarly journals Vegetable Oil-Based Resins Reinforced with Spruce Bark Powder and with Its Hydrochar Lignocellulosic Biomass

2021 ◽  
Vol 11 (22) ◽  
pp. 10649
Author(s):  
Roxana Dinu ◽  
Iuliana Bejenari ◽  
Irina Volf ◽  
Alice Mija
Keyword(s):  
Vegetable Oil ◽  
Epoxy Resins ◽  
Catalytic Effect ◽  
Linseed Oil ◽  
Tensile Tests ◽  
Multiple Roles ◽  
Crosslinking Reaction ◽  
Dsc Analysis ◽  
Spruce Bark ◽  
Epoxidized Linseed Oil

A bio-based polymeric matrix was developed by the copolymerization of a vegetable oil-based epoxy, epoxidized linseed oil (ELO), with dodecenyl succinic anhydride (DDSA). To obtain eco-friendly bio-composites, this matrix was combined with a natural filler: spruce bark powder (SB) with its hydrochar (HC) in various proportions ranged from 1 to 30 wt.%. The reactivities of these formulations were studied by DSC analysis that highlighted that both fillers have a high catalytic effect on the ELO–DDSA crosslinking reaction. The complementary studies by TGA, DMA, tensile tests, water absorption and Shore tests had shown that both HC and SB bring improvements to the mechanical properties of the composites, fulfilling multiple roles: (i) Both act as co-reactants in the copolymerization mechanism; (ii) HC acts as reinforcement, consolidating the network and providing stiffness and rigidity; and (iii) SB acts as plasticizer for reducing the brittle character of the epoxy resins.

Synthesis of a phosphorus–nitrogen-containing flame retardant and its application in epoxy resin

2018 ◽  
Vol 31 (2) ◽  
pp. 186-196 ◽  
Author(s):  
Shuang Yang ◽  
Yefa Hu ◽  
Qiaoxin Zhang
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Heat Release Rate ◽  
Flame Retardancy ◽  
Release Rate ◽  
Epoxy Resins ◽  
Proton Nuclear Magnetic Resonance ◽  
Scanning Calorimetry ◽  
Cone Calorimeter Test

In this article, a phosphorus–nitrogen-containing flame retardant (DOPO-T) was successfully synthesized by nucleophilic substitution reaction between 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and cyanuric chloride. The chemical structure of DOPO-T was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance (NMR) and phosphorous-31 NMR, and elemental analysis. DOPO-T was then blended with diglycidyl ether of bisphenol-A to prepare flame-retardant epoxy resins. Thermal properties, flame retardancy, and combustion behavior of the cured epoxy resins were evaluated by differential scanning calorimetry, thermogravimetric analysis, limited oxygen index (LOI) measurement, UL94 vertical burning test, and cone calorimeter test. The results indicated that the glass transition temperature ( Tg) and temperature at 5% weight loss of epoxy resin (EP)/DOPO-T thermosets were gradually decreased with the increasing content of DOPO-T. DOPO-T catalyzed the decomposition of EP matrix in advance. The flame-retardant performance of EP thermosets was significantly enhanced with the addition of DOPO-T. EP/DOPO-T-0.9 sample had an LOI value of 36.2% and achieved UL94 V-1 rating. In addition, the average of heat release rate, peak of heat release rate, average of effective heat of combustion, and total heat release (THR) of EP/DOPO-T-0.9 sample were decreased by 32%, 48%, 23%, and 31%, respectively, compared with the neat EP sample. Impressively, EP/DOPO-T thermosets acquired excellent flame retardancy under low loading of flame retardant.

scholarly journals Preparation and Characterization of Polypropylene/Carbon Nanotubes (PP/CNTs) Nanocomposites as Potential Strain Gauges for Structural Health Monitoring

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 814 ◽  
Author(s):  
Bartolomeo Coppola ◽  
Luciano Di Maio ◽  
Loredana Incarnato ◽  
Jean-Marc Tulliani
Keyword(s):  
Carbon Nanotubes ◽  
Thermo Gravimetric Analysis ◽  
Tensile Tests ◽  
Strain Gauges ◽  
Gauge Factor ◽  
Gravimetric Analysis ◽  
Strain Sensing ◽  
Scanning Calorimetry ◽  
Impedance Variation ◽  
Mechanical Tensile

Polypropylene/carbon nanotubes (PP/CNTs) nanocomposites with different CNTs concentrations (i.e., 1, 2, 3, 5 and 7 wt%) were prepared and tested as strain gauges for structures monitoring. Such sensors were embedded in cementitious mortar prisms and tested in 3-point bending mode recording impedance variation at increasing load. First, thermal (differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA)), mechanical (tensile tests) and morphological (FE-SEM) properties of nanocomposites blends were assessed. Then, strain-sensing tests were carried out on PP/CNTs strips embedded in cementitious mortars. PP/CNTs nanocomposites blends with CNTs content of 1, 2 and 3 wt% did not show significant results because these concentrations are below the electrical percolation threshold (EPT). On the contrary, PP/CNTs nanocomposites with 5 and 7 wt% of CNTs showed interesting sensing properties. In particular, the best result was highlighted for the PP/CNT nanocomposite with 5 wt% CNTs for which an average gauge factor (GF) of approx. 1400 was measured. Moreover, load-unload cycles reported a good recovery of the initial impedance. Finally, a comparison with some literature results, in terms of GF, was done demonstrating the benefits deriving from the use of PP/CNTs strips as strain-gauges instead of using conductive fillers in the bulk matrix.

Significant enhancement of fracture toughness and mechanical properties of epoxy resin using CTBN‐grafted epoxidized linseed oil

2019 ◽  
Vol 137 (2) ◽  
pp. 48276 ◽  
Author(s):  
Quang‐Vu Bach ◽  
Cuong Manh Vu ◽  
Huong Thi Vu ◽  
Hoa Binh Vu ◽  
Tuyen Van Nguyen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Epoxy Resin ◽  
Linseed Oil ◽  
Significant Enhancement ◽  
Epoxidized Linseed Oil

scholarly journals New Biosourced Flame Retardant Agents Based on Gallic and Ellagic Acids for Epoxy Resins

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4305 ◽  
Author(s):  
Valeriia Karaseva ◽  
Anne Bergeret ◽  
Clément Lacoste ◽  
Hélène Fulcrand ◽  
Laurent Ferry
Keyword(s):  
Phenolic Compounds ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Flame Retardants ◽  
Fire Behavior ◽  
Diglycidyl Ether ◽  
Scanning Calorimetry ◽  
Burning Behavior ◽  
Borate Ester ◽  
Thermal Stability Of

The aim of this work was an investigation of the ability of gallic (GA) and ellagic (EA) acids, which are phenolic compounds encountered in various plants, to act as flame retardants (FRs) for epoxy resins. In order to improve their fireproofing properties, GA and EA were treated with boric acid (to obtain gallic acid derivatives (GAD) and ellagic acid derivatives (EAD)) to introduce borate ester moieties. Thermogravimetric analysis (TGA) highlighted the good charring ability of GA and EA, which was enhanced by boration. The grafting of borate groups was also shown to increase the thermal stability of GA and EA that goes up respectively from 269 to 528 °C and from 496 to 628 °C. The phenolic-based components were then incorporated into an epoxy resin formulated from diglycidyl ether of bisphenol A (DGEBA) and isophorone diamine (IPDA) (72, 18, and 10 wt.% of DGEBA, IPDA, and GA or EA, respectively). According to differential scanning calorimetry (DSC), the glass transition temperature (Tg) of the thermosets was decreased. Its values ranged from 137 up to 108 °C after adding the phenolic-based components. A cone calorimeter was used to evaluate the burning behavior of the formulated thermosets. A significant reduction of the peak of heat release rate (pHRR) for combustion was detected. Indeed, with 10 wt.% of GA and EA, pHRR was reduced by 12 and 44%, respectively, compared to that for neat epoxy resin. GAD and EAD also induced the decrease of pHRR values by 65 and 33%, respectively. In addition, a barrier effect was observed for the resin containing GAD. These results show the important influence of the biobased phenolic compounds and their boron derivatives on the fire behavior of a partially biobased epoxy resin.

scholarly journals Synthesis of Benzene Tetracarboxamide Polyamine and Its Effect on Epoxy Resin Properties

Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 782 ◽  
Author(s):  
Seoyoon Yu ◽  
Wonjoo Lee ◽  
Bongkuk Seo ◽  
Chung-Sun Lim
Keyword(s):  
Epoxy Resin ◽  
Epoxy Resins ◽  
High Performance ◽  
Protective Coatings ◽  
Industrial Applications ◽  
Thermomechanical Properties ◽  
Scanning Calorimetry ◽  
Adhesive Properties ◽  
Cross Sectional ◽  
Value Determination

Epoxy resins have found various industrial applications in high-performance thermosetting resins, high-performance composites, electronic-packaging materials, adhesives, protective coatings, etc., due to their outstanding performance, including high toughness, high-temperature performance, chemical and environmental resistance, versatile processability and adhesive properties. However, cured epoxy resins are very brittle, which limits their applications. In this work, we attempted to enhance the toughness of cured epoxy resins by introducing benzene tetracarboxamide polyamine (BTCP), synthesized from pyromellitic dianhydride (PMDA) and diamines in N-methyl-2-pyrrolidone (NMP) solvent. During this reaction, increased viscosity and formation of amic acid could be confirmed. The chemical reactions were monitored and evidenced using 1H-NMR spectroscopy, FT-IR spectroscopy, water gel-phase chromatography (GPC) analysis, amine value determination and acid value determination. We also studied the effect of additives on thermomechanical properties using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamical mechanical analysis (DMA), thermomechanical analysis (TMA) and by measuring mechanical properties. The BTCP-containing epoxy resin exhibited high mechanical strength and adhesion strength proportional to the amount of BTCP. Furthermore, field-emission scanning electron microscopy images were obtained for examining the cross-sectional morphology changes of the epoxy resin specimens with varying amounts of BTCP.

An improved simplified approach for curing kinetics of epoxy resins by nonisothermal differential scanning calorimetry

2017 ◽  
Vol 30 (3) ◽  
pp. 303-311 ◽  
Author(s):  
Chao Chen ◽  
Yanxia Li ◽  
Yizhuo Gu ◽  
Min Li ◽  
Zuoguang Zhang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Epoxy Resin ◽  
Kinetic Parameters ◽  
Epoxy Resins ◽  
Curing Kinetics ◽  
Scanning Calorimetry ◽  
Simplified Approach ◽  
Curing Kinetic ◽  
Autocatalytic Curing ◽  
Kinetics Of

The curing kinetics of two different types of commercial epoxy resins were investigated by means of nonisothermal differential scanning calorimetry (DSC) in this work. The complex curve of measured heat flow of CYCOM 970 epoxy resin was simplified with the method of resolution of peak. Two typical autocatalytic curing reaction curves were gained and the kinetic parameters of the curing process were demonstrated by combination of those two reactions. The Kissinger method was adopted to obtain the values of the activation energy. The parameters of curing kinetic model were acquired according to the fitting of Kamal model. Isothermal DSC curve of CYCOM 970 epoxy resin obtained using the experimental data shows a good agreement with that theoretically calculated. Then, 603 epoxy resin was investigated by the simplified method and the kinetic parameters were received through the same procedure. The nonisothermal DSC curve tested according to the recommended cure cycle of 603 epoxy resin is also consistent with the calculated results. This improved simplified approach provides an effective method to analyze the curing kinetics of the epoxy resins with complex DSC curves as similar to this study.

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.

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