Epoxy Resin-modified, Urea-formaldehyde/Silicon Networks for High Impact Strength and Thermal Stability

Abstract

A variety of toughening agents are used to modify epoxy resins that improve the fracture toughness of the epoxy systems. The basic goal in toughening cross-linked epoxy resins that are normally brittle at room temperature is to improve crack resistance and toughness without significantly decreasing other important inherent properties, such as the flexural modulus and the thermomechanical properties of the original epoxy resins.In the present study, thermally stable epoxy resin modified urea-formaldehyde/silicon blends have been prepared by in situ polymerization technique. The materials were modified with triethylenetetramine (hardener) to obtain highly cross-linked thermosetting resins. The physical properties of the resulting blends were evaluated by measuring the impact strength, which is found to be increased by more than 25% of that of the cured and blank epoxy resin. The impact fracture surfaces are examined using scanning electron microscopy (SEM) to reveal the morphological changes.The hardness was found to be high in the case of modified epoxy resin as compared to blank epoxy. The influence on the thermal properties and the behavior of different curing agents on resins were investigated by thermogravimetrc analysis (TGA) and differential scanning calorimetry (DSC). The results of the modified epoxy resins showed remarkably high thermal stability as well as a higher degree of solvent resistance as compared with blank epoxy resin.

A designer Schiff based motif offered dual dynamic exchangeable bonds, faster curing and closed‐loop circularity in epoxy vitrimers

“…Epoxy resins are widely used for the fabrication of adhesives, coatings and in the creation of composites due to their ease of handling, processability, excellent solvent resistance, dimensional stability, and resistance to corrosion. 31,32 High-performance lightweight composite materials are of great interest due to their outstanding mechanical and thermal properties. Employing epoxy resins as the matrix for composites require material with low thermal expansion coefficient, high heat and moisture stability 31,33 and these parameters can be achieved through modifications in the pendant and backbone groups and the highly cross-linked threedimensional networks in epoxy amine blends exhibit high mechanical properties and is an exceptional adhesive.…”

“…31,32 High-performance lightweight composite materials are of great interest due to their outstanding mechanical and thermal properties. Employing epoxy resins as the matrix for composites require material with low thermal expansion coefficient, high heat and moisture stability 31,33 and these parameters can be achieved through modifications in the pendant and backbone groups and the highly cross-linked threedimensional networks in epoxy amine blends exhibit high mechanical properties and is an exceptional adhesive. 32 However, epoxy curing with amine results in a non-reversible reaction, and the matrix does not produce depolymerization products, thus failing the recycling strategy.…”

“…Epoxy resins are widely used for the fabrication of adhesives, coatings and in the creation of composites due to their ease of handling, processability, excellent solvent resistance, dimensional stability, and resistance to corrosion 31,32 . High‐performance lightweight composite materials are of great interest due to their outstanding mechanical and thermal properties.…”

Effect of urea–formaldehyde nanoparticles on the barrier property and delamination resistance for epoxy coating

“…Yuan et al (2006) prepared poly (urea–formaldehyde) as a shell material of microcapsules and applied to the fabrication of self-healing composites. Athawale and Alhousami (2009) designed a kind of toughening cross-linked epoxy resins, which was modified by UF by in situ polymerization technique.…”

Synthesis and Characterization of Novel Sulphanilamide/Epoxy Resin Modified Polyester for Thermal Stability and Impact Strength

“…Epoxy resins based on diglycidyl ether of bisphenol-A have been used extensively as thermosetting materials in the development of high-performance lightweight fiber reinforced composites. Epoxy resin exhibits many desirable properties, such as high strength and modulus, excellent chemical and solvent resistance, good thermal and electrical properties and outstanding adhesions [1]- [8].…”