Fracture and adhesion behaviors of epoxy resins modified with poly(amine‐quinone)

Abstract

An amine-quinone monomer, i.e. 2,5-bis(4,4 -methylenedianiline)-1,4-benzoquinone (BB), was synthesized by the Michael addition of 4,4 -diaminodiphenyl methane with 1,4-benzoquinone. To evaluate the effect of BB content on the glass transition temperature (T g ) and crosslinking density (ρ) of cured diglycidyl ether of bisphenol A (DGEBA)/BB systems, storage modulus and loss factor measurements were obtained using dynamic mechanical analysis. The mechanical properties of the systems were determined in terms of the fracture toughness, impact strength, and adhesion strength. As a result, the ρ values of the systems were found to decrease systematically as the BB content increased. The fracture toughness and adhesion strength of the systems increased with increasing BB content. These results indicate that the addition of BB into epoxy resins increases the free volume of the epoxy network and absorbs the deformation energy, resulting in an improvement of the mechanical properties of the DGEBA/BB systems.

Solid-Solid Interfaces

“…The total work of adhesion is reduced to (4)(5)(6)(7)(8)(9) In the particular case such as London's forces across the interface, the work of adhesion is determined because the non-dispersive part becomes zero. The only existence of London interactions at the interface between two adherents leads to G / W L 12 (4)(5)(6)(7)(8)(9)(10) where G is the adhesive strength of the assembly. The only existence of London interactions at the interface between two adherents leads to G / W L 12 (4)(5)(6)(7)(8)(9)(10) where G is the adhesive strength of the assembly.…”

“…Gutmann also suggested that the free energy of an acidbase interaction could be approximated by a two-parameter equation of the form (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) where DG 12 AB is the Gibbs free energy of the acid-base adduct formation, DN B the donor number of the base, and AN A the acceptor number of the acid. This means that a plot of the DN for a series of donors vs. -DG of their adduct formation with a given acid brings up a straight line, allowing the determination of a A and b A .…”

“…(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16), to water (w) yields g AB w ¼ 2ð25:5 Â 25:5Þ 1=2 (4-17) (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16), to water (w) yields g AB w ¼ 2ð25:5 Â 25:5Þ 1=2 (4-17)…”

“…Fowkes [50] proposed that the enthalpy of acid-base adduct formation is related to the shift of infrared frequency (Dv) of its absorption band for specific functional groups involved in the acid-base interaction, according to the following equation: (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) where DG 12 AB is the Gibbs free energy of the acid-base adduct formation, Dk 12 AB the correlation constant between the IR wave number shift and enthalpy, and Dv 12 AB the infrared frequency shift. k AB is a characteristic constant of the functional group determined on the basis of infrared and micro-calorimetrical from the results of adduct formation.…”

“…For example, the latter is equal to -0.99 kJ/mol cm in the carbonyl group. (4)(5)(6)(7)(8)(9)(10)(11)(12), is reduced to This methodology has recently been proved not only for polymer-solvent adduction but for polymer-polymer [51] and polymer-metal [52] adduction.…”