Tetraglycidyl Diaminodiphenyl Methane Epoxies Research Articles

Fully aminated rigid‐rod aromatic polyamide efficiently reinforces tetraglycidyl diamino diphenyl methane epoxy resin and its carbon fiber composite

AbstractTetraglycidyl diamino diphenyl methane (TGDDM) and its carbon fiber composite are widely studied and used because of their heat resistance and high performance. In order to obtain efficient reinforcing effects in a simple manner, we adopt the idea of molecular composite—uniformly dispersing the rigid‐rod macromolecules in the TGDDM matrix. Herein, we prepared fully aminated‐poly(p‐phenylene terephthalamide) by direct polycondensation and hydrogenation reduction as the reinforcing agent. The fully aminated‐PPTA is distributed uniformly in the cross‐linked epoxy resin (EP) network by chemical bonds, and achieves efficient reinforcement. With the addition of only 0.5 wt% fully aminated‐PPTA, the tensile strength and Young's modulus of EP are improved to 127.7 ± 7.4 MPa (+28%) and 3.36 ± 0.15 GPa (+44%); the flexural strength and modulus are improved to 209.6 ± 9.4 MPa (+42%) and 3.70 ± 0.14 GPa (+37%); the notch impact strength is improved by 32%. Crucially, the heat resistance of EP almost remains unchanged. Furthermore, the flexural properties and interlaminar shear strength of the carbon fiber composite are also comprehensively increased. Compared with other modified fillers, the fully aminated‐PPTA is simple to prepare and blend, and is an efficient reinforcing agent for TGDDM and its carbon fiber composite benefitting from its rigid‐rod main chain and amino side groups.Highlights Molecular composite can achieve excellent strengthen and toughen effects. Fully aminated‐PPTA is embedded uniformly in EP network by chemical bonds. TGDDM is effectively reinforced without deteriorated heat resistance. Fully aminated‐PPTA is also a comprehensive reinforcement for EP/CF composite.

Evaluation of augmented thermal, thermo-mechanical, mechanical properties of nano alumina reinforced TGDDM epoxy nanocomposites

N,N′-Tetraglycidyldiaminodiphenyl methane (TGDDM) was reinforced with various weight fractions (0.5, 1, and 1.5 wt%) of amine functionalized nano alumina (F-Al) were cured with diaminodiphenyl-methane (DDM). FT-IR analysis revealed that formation of functionalized nano alumina (F-Al) structure, was brought about via coupling agent APTES. Furthermore, the morphology of TGDDM epoxy nanocomposites was studied using X-ray Diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), microscopic analysis and an atomic force microscope (AFM). We found a bonding relationship between TGDDM epoxy and F-Al in TGDDM/F-Al nanocomposites It was interesting to note that the values of tensile, flexural and impact strength of 1 wt% F-Al reinforced TGDDM epoxy nanocomposites were found to be 141.5, 192.5 MPa, and 92.4 J/m2, respectively., which resulted in a substantial improvement in the dynamic mechanical analysis (DMA) to 4.3 and 5.5 for 0.5 and 1 wt% F-Al reinforced TGDDM epoxy nanocomposites and the glass transition temperature (Tg) increased from 210°C to 225°C as the F-Al content increased. The initial degradation temperature (IDT) of 0.5, 1, and 1.5 wt% F-Al reinforced TGDDM epoxy nanocomposites were significantly enriched to 328°C, 345°C, and 335°C respectively from 290°C of neat (TGDDM) epoxy matrix. Likewise, the char yield for the neat (TGDDM) epoxy matrix was 13% and that for 0.5, 1, and 1.5 wt% F-Al reinforced TGDDM epoxy nanocomposites were 17%, 25%, and 20% respectively. It is feasible to state unequivocally that considerable F-Al diffusion within the TGDDM epoxy can only occur at low weight percentages. The results clearly showed that F-Al reinforced TGDDM epoxy nanocomposites may be investigated for advanced high performance industrial engineering applications.

Influence on organic inorganic hybrid (mullite) fibre on mechanical, thermo-mechanical and morphological properties of TGDDM epoxy nanocomposites

ABSTRACT The objective of the present work is to synthesise N,N’-tetraglycidyldiaminodiphenylmethane (TGDDM) epoxy resin via 4,4ʹ-diaminodiphenylmethane (DDM) and epichlorohydrin in order to obtain tetra-functional epoxy with improved properties. The molecular structure of TGDDM epoxy resin was confirmed from fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectral data. Theamine functionalised mullite fibre (F-MF) was synthesised through using 3-aminopropyltriethoxysilane as a coupling agent to prepare amino groups on the surface mullite fibreand its structure confirmed with FTIR. The TGDDM epoxy resin was reinforced with variant weight percentages (1–3 wt%) of F-MF nanocomposite was cured with DDM. The morphology of TGDDM and nanocomposites was examined using X-ray powder diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscope (SEM). .We observed improvement in properties of thermal, thermo-mechanical, mechanical, di-electric constant and water absorption behaviour of TGDDM epoxy nanocomposites.

Development of novel TGDDM epoxy nanocomposites for aerospace and high performance applications – Study of their thermal and electrical behaviour

The present work focuses on a study of the thermal and electrical behaviour of pure N,N′-tetraglycidyl diaminodiphenylmethane (TGDDM) for use in aerospace, high performance applications. The synthesis of the tetraglycidyl epoxies was done and they were characterized by FT-IR (Fourier transform infrared spectra) and Nuclear magnetic resonance spectra (1H NMR and 13C NMR). Nanoclay and POSS-amine nanoreinforcements denoted as N1 and N2 were incorporated into the synthesized epoxy resins. Curing was done with diaminodiphenylmethane (DDM) and bis(3-aminophenyl)phenylphosphine oxide (BAPPO) curing agents denoted as X and Y, respectively. The thermal behaviour of the tetraglycidyl resins and their corresponding nanocomposites was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The electrical behaviour namely dielectric strength, comparative tracking index (CTI), volume resistivity, surface resistivity and arc resistance of the nanocomposites was also studied and the interesting results obtained are discussed.

Synthesis and characterization of organic-inorganic hybrid clay filled and bismaleimide—siloxane modified epoxy nanocomposites

Organic-inorganic hybrids involving organo-modified montmorillonite (OMMT) clay and tetraglycidyl diamino diphenyl methane epoxy (TGDDM) were prepared via in situ polymerization by the homogeneous dispersion of various percentages (1–5% w/w) of clay in epoxy matrix resin. The resulting homogeneous epoxy—clay hybrids were modified with 10 wt% of hydroxyl terminated polydiemthyl siloxane (HTPDMS) using γ—aminopropyltriethoxysilane (γ-APS) as coupling agent in the presence of tin catalyst. The siliconized epoxy-clay prepolymers were further modified separately with 15 wt% of bismaleimide (BMI) monomers and cured with diaminodiphenylmethane. The reactions involved during the curing process between epoxy resin, siloxane and BMI were confirmed by using FTIR and DSC curing analysis. The differential scanning calorimetry (DSC) show that the significant increase in glass transition temperatures in the clay filled hybrid epoxy systems than that of neat epoxy resin. The data obtained from thermal studies indicates that the appreciable improvement in hybrid systems was due to the incorporation of MMT clay, BMI and siloxane into epoxy systems. Scanning electron microscopy (SEM) of the hybrid systems show that the homogenous morphology. X-ray diffraction analysis of the clay hybrid systems shows that the amorphous diffraction patterns and the peaks are broadened and nearly disappeared after 24 h swelling, suggesting the formation of exfoliated structure.

Investigation of the reaction mechanism of different epoxy resins using a phosphorus‐based hardener

AbstractIn this work, the fundamental kinetic and structure/property information for a novel phosphorus‐based hardener, bis(4‐aminophenoxy) phosphonate is cured with a range of common epoxy resins such as diglycidyl ether of bisphenol A, tri glycidyl p‐amino phenol and tetra glycidyl diamino diphenyl methane (TGDDM) at various cure temperatures. The rate coefficients k1 and k2 for the primary and secondary amine epoxide addition reactions, respectively, were determined and were found to exhibit a positive substitution effect for the TGAP and TGDDM epoxy resins. Etherification or internal cyclization were shown to be important at higher levels of cure conversion, with these reactions being more significant for the TGAP/BAPP system. Some basic structure/property relationships were established between the glass transition temperature (Tg) and epoxide conversion. The master curve obtained for the superimposition of the various cure temperatures for each epoxy demonstrated the independence of the cure mechanism with temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99:3288–3299, 2006

96/00356 FAMSAP: A code to analyze the dynamic response of PWR fuel assemblies in LOCA and seismic conditions and its application to QNPP

The effects of irradiation in a fission reactor at 4 K on the shear and compressive properties at 4 K of ITER candidate insulation systems have been examined. The shear strength was measured by the short-beam shear test technique. Fast neutron fluences from 0.9 to 3 × 1022 n m−2 were obtained at 4 K. Results indicate that the shear strength and flexural modulus were both sensitive to the neutron fluence; the compressive strength and modulus were less sensitive. Systems of flexibilized diglycidyl ether of bisphenol-A epoxy were more sensitive to irradiation than systems based on tetraglycidyl diaminodiphenyl methane epoxy.

Effects of neutron/gamma irradiation at 4 K on shear and compressive properties of insulation

The effects of irradiation in a fission reactor at 4 K on the shear and compressive properties at 4 K of ITER candidate insulation systems have been examined. The shear strength was measured by the short-beam shear test technique. Fast neutron fluences from 0.9 to 3 × 10 22 n m −2 were obtained at 4 K. Results indicate that the shear strength and flexural modulus were both sensitive to the neutron fluence; the compressive strength and modulus were less sensitive. Systems of flexibilized diglycidyl ether of bisphenol-A epoxy were more sensitive to irradiation than systems based on tetraglycidyl diaminodiphenyl methane epoxy.