Application Of Epoxy Research Articles

The synthesis and characterization of a novel phosphorus–nitrogen containing flame retardant and its application in epoxy resins

ABSTRACTA novel, halogen‐free, phosphorus–nitrogen containing flame retardant 2[4‐(2,4,6‐Tris{4‐[(5,5‐dimethyl‐2‐oxo‐2λ5‐[1,3,2]dioxaphosphinan‐2‐yl)hydroxymethyl]phenoxy}‐(1,3,5)‐triazine (TNTP) was successfully synthesized in a three‐step process, and characterized by FTIR, NMR spectroscopy, mass spectra, and elemental analysis. A series of modified DGEBA epoxy resin with different loadings of TNTP were prepared and cured by 4,4‐diaminodiphenylsulfone (DDS). Thermal gravimetric analysis and vertical burning test (UL‐94) were used to evaluate the flame retardancy of TNTP on DGEBA epoxy resin. The results showed that TNTP had a great impact on flame retardancy. All modified thermosets by using TNTP exhibited higher Tg than pure DGEBA/DDS. The loading of TNTP at only 5.0 wt % could result in satisfied flame retardancy (UL‐94, V‐0) together with high char residue (27.3%) at 700°C. The addition of TNTP could dramatically enhance the flame retardancy of DGEBA epoxy resins, which was further confirmed by the analysis of the char residues by scanning electron microscopy and FTIR. Furthermore, no obviously negative effect was found on the Izod impact strength and flexural property of DGEBA epoxy resins when TNTP loading limited in 5.0 wt %. DGEBA/DDS containing 2.5 wt % TNTP could enhance Izod impact strength from 10.47 to 10.94 kJ m−2, and showed no appreciable effect on the flexural property (85.20 MPa) comparing with pure DGEBA/DDS (87.03 MPa). Results indicated that TNTP as a phosphorus–nitrogen synergistic intumescent flame retardant could be used for DGEBA epoxy resin. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41079.

The synthesis of a novel graphene-based inorganic–organic hybrid flame retardant and its application in epoxy resin

In this paper, a novel graphene-based inorganic–organic hybrid flame retardant (GFR) was prepared via sol–gel reaction of FGO and phenyl-bis-(triethoxysilylpropyl) phosphamide (PBTP) and characterized by FT-IR, XPS, XRD, TGA and AFM. The influence of the GFR on the thermal stability and flame retardance of epoxy resin composites were characterized by TGA, LOI as well as micro-cone, which indicated that GFR brought a good effect in enhancing the residual char and flame retardance of epoxy composites. The dynamic mechanical properties and electrical properties of EP composites were also analyzed.

Effects of Lignin Derivatives on Cross-Link Density and Dielectric Properties in the Epoxy-Based Insulating Materials for Printed Circuit Boards

Bio-plastics are made from renewable biomass sources. We focus on lignin and develop epoxy resins containing lignin derivatives. We describe the preparation and application of epoxy resin containing lignin as a matrix. Soda-lignin (SLG) is obtained from black liquor in a soda pulp process. First, we use a lignin manufacturing process in which a methanol extraction method enabled reduction in the molecular and hydroxyl equivalent weights of lignin and removal of SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and cellulose. Second, we investigate the ratio of diglycidyl ether of bisphenol-A (DGEBA) and methanol extraction SLG (me-SLG). From the viewpoint of cross-linking density and dielectric properties, 100/84 phr in the DGEBA/me-SLG casting system is found to be preferable. Finally, we try to fabricate an insulating material made up of DGEBA/me-SLG for an aluminum-based printed circuit board, and it achieves standard values.

Preparation of diamine-POSS/Ag hybrid microspheres and its application in epoxy resin

The synthesis of polyhedral oligomeric silsesquioxane (POSS) via hydrolytic co-condensation of phenyltriethoxysilane (PTES) and γ-aminopropyltrieth-oxysilane (APS) was presented in this paper. The microspheres with mean diameter of 1.83 μm were precipitated from solvent phase through self-assembly when solvent phase was changed. After the reduction of hydrazine hydrate, POSS/Ag hybrid microspheres were obtained based on the chelation of external amino-groups to silver ions. The hybrid microspheres modified epoxy resin was also studied in the work. The structure and particle size distribution of POSS, feature and silver content of the POSS/Ag core/shell microspheres, heat resistance, thermal conductivity and comprehensive mechanical properties of the epoxy resin modified by diamine-POSS/Ag were characterized by NMR, FTIR, SEM, Laser Particle Sizer, TGA and Flat Heat Conduction Coefficient, Universal Testing Machine. It was found that POSS was cage-like structures with two amino-groups, amino group content was 2.12 mmol/g and the silver conten was 47.96 %, respectively. When Ag addition reached 5 %, thermal conductivity of the modified epoxy resin has increased fourfold four times greater than pure, and the heat resistance increased by 35 °C. Moreover, the bending strength and impact strength of the modified resin were 127 MPa and 11.94 KJ/m2, respectively, compared with pure epoxy resin, both of which have improved.

Optimization of sol–gel coatings on the surface of ammonium polyphosphate and its application in epoxy resin

Surface-modified ammonium polyphosphate was prepared by a sol–gel method using tetraethoxysilane and methyltriethoxysilane as precursors. The reaction conditions were optimized in order to decrease the water solubility of the ammonium polyphosphate. Then, modified ammonium polyphosphate and ammonium polyphosphate were used as flame retardants for an epoxy resin to constitute an intumescent flame-retardant system. The combustion behavior and the water resistance of epoxy resin and epoxy resin–containing ammonium polyphosphate or modified ammonium polyphosphate were investigated by limiting oxygen index and UL-94 test. The results show that the water resistance of epoxy resin and modified ammonium polyphosphate composites was greatly improved. The water contact angle of the modified ammonium polyphosphate reached 138°, for which the results show that there are a lot of hydrophobic groups on the surface of ammonium polyphosphate. And then the properties of the modified ammonium polyphosphate and the chemical bonding of the surface elements in the modified ammonium polyphosphate were analyzed using a Fourier transform infrared spectrophotometer, scanning electron microscopy analysis, and X-ray photoelectron spectroscopy. The results show that both tetraethoxysilane and methyltriethoxysilane hydrolyze and condense to form a dense layer structure on the surface of ammonium polyphosphate and can react with the hydroxyl groups on the surface of ammonium polyphosphate and form a new Si–O–P bond.

Synthesis of three novel phosphorus-containing flame retardants and their application in epoxy resins

One symmetric diamine ( 4) and two symmetric phenols ( 5) and ( 6) were synthesized as phosphorus-containing flame retardants. The synthesis comprised a two-step procedure: the condensation of p-phenylenediamine with benzaldehyde, 4-hydroxybenzaldehyde and 2-hydroxybenzaldehyde respectively, followed by the addition of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the imine linkage. The structures of ( 4)–( 6) were characterized by FTIR, NMR and mass spectra. ( 4)–( 6) served as co-curing agents of diaminodiphenylmethane for epoxy resins, and epoxy thermosets exhibited excellent flame retardancy, moderate changes in glass transition temperature ( T g) and thermal stability. When the phosphorus content reached 1.0 wt.%, the epoxy resin system met the UL-94 V-0 classification and the limiting oxygen index (LOI) reached more than 35.6, probably because of the nitrogen–phosphorus synergistic effect.

Shear behavior of masonry panels strengthened by high strength steel cords

The present experimental study was aimed to investigate the effectiveness of an alternative shear reinforcement technique, based on the use of high strength steel cords embedded in a cementitious matrix (SRG: Steel Reinforced Grout). Although FRPs are successfully used as shear reinforcement in masonry retrofitting, such a strengthening method represents a new opportunity to restoring ambit, with considerable development in unreinforced masonry (URM) strengthening. Particularly, the non application of epoxy resins may contribute to solve important problems in terms of high temperature and long term behavior, compatibility and reversibility of reinforcement. A series of eight URM panels and 23 strengthened panels manufactured using two different types of mortar have been subjected to diagonal compression tests. Different reinforcement configurations were evaluated. Experimental results pointed out a significant increase in shear strength and stiffness, with interesting implications for the practical utilization of the technique studied. Finally, experimental results are also used to calibrate existing analytical formulations for ultimate shear strength prediction.

Novel epoxy formulations for high energy radiation curable composites

It has been widely recognised that high energy radiation can be effectively applied to the cure of epoxy resins in applications as composite matrices or structural adhesives with improvements in product quality and/or reduction in production costs. In the presence of suitable initiators, polymerisation of epoxies occurs via cationic mechanism, thus restricting the choice of the resin system components to species which do not contain electron donor groups. The present investigation is aimed to identify suitable co-monomers to be formulated with an epoxy resin, resulting in different cure reaction kinetics and application properties of the cured resin. In particular, four different anhydride types, three dicarboxylic and one tetracarboxylic, have been formulated at the same weight ratio with a diglydilether of bisphenol F and a photo-initiator. Resin samples, irradiated at different integrated doses, have been characterised with solubility tests, dynamic-mechanical thermal analysis and three point flexural tests, showing a response which is strongly affected by the specific chemical structure of the anhydride co-monomer. Post-irradiation thermal treatments carried out on samples irradiated at the lower dose suggest different reaction patterns, with different controlling factors depending on the activation mechanism (temperature or γ-rays).

Modelling the Cure of a Commercial Epoxy Resin for Applications in Resin Transfer Moulding

Modelling the Cure of a Commercial Epoxy Resin for Applications in Resin Transfer Moulding

The Use of Epoxy Resins in Field Projects for Stone Stabilization

ABSTRACTThe direct application of epoxy resins to deteriorating stone often encounters problems of penetration and color formation. Conservation scientists have worked around these problems by using organic solvents as carriers and have successfully consolidated stone with epoxy resins in a large number of projects. Work in Poland, Czechoslovakia, Italy and the United States is described. In Europe the methodology has evolved to treat objects of moderate size and isolated parts of buildings while in the United States procedures have been developed for stabilizing large portions of major buildings.

The Application of Epoxy Resins for the Consolidation of Porous Stone

The Application of Epoxy Resins for the Consolidation of Porous Stone

Application of Epoxy Resins in Electrical Apparatus

This summarizes the important physical and electrical characteristics of these diverse and highly useful insulating materials. Factors of chemical structure which influence the resulting resin properties are discussed. The great variety of properties which can be achieved through variations in this one class of resins is emphasized. A range of applications of these resins is mentioned and illustrated.

Erratum for “Application of Epoxy Resins in Tunnel Lining Concrete Repair”

Erratum for “Application of Epoxy Resins in Tunnel Lining Concrete Repair”

Application of Epoxy Resins in Tunnel Lining Concrete Repair

Concrete lining in a large diameter tunnel spillway damaged by cavitation erosion caused by variable high flows up to 20,000 cfs was repaired by use of bonded concrete, and epoxy bonded epoxy mortar. Epoxy bonded epoxy mortar was used to make the repairs except in the damaged areas of large volume. The repair area to receive epoxy mortar was prepared by bushhammering, chipping, or sandblasting. The surfaces of the concrete were made completely dry. Seeping hairline cracks were rendered dry by chemical grouting. Air and concrete temperature was maintained at about 60° F by a heating system. A clear epoxy bond coat was applied to a small area of prepared concrete surface. Epoxy mortar was applied to the bond coat while the bond coat was in a fluid to tacky condition. Curing and post curing of the epoxy mortar by use of propane infrared heaters and heat lamps were required. Painting of the cured mortar with an epoxy phenolic paint was specified.

エポキシ樹脂の絶縁塗料への応用

エポキシ樹脂の絶縁塗料への応用

Studies on New Powder Specimen Techniques by the Application of Epoxy Resin

Studies on New Powder Specimen Techniques by the Application of Epoxy Resin

CORROSION RESEARCH ROUND‐UP

GERMANY Recent applications of epoxy resins in surface protection. Reference is made to the importance of epoxy resins in surface protection, and to the matter of solvent‐free resin hardener systems in the light of the latest practical experience; including photographs and practical applications, with special reference to Araldite.— (H. Zumstein, Werks. u. Korr., 1959, 10 (10), 605–608.)