تأثير ميزان اتصال عرضي و اندازه‌ي نانوذره‌يMIL-53(Fe) بر خواص رزين اپوكسي DGEBA پخته‌شده با EDA

The effect of the cross-linking rate an‎d the size of MIL-53(Fe) nanoparticle on the properties of the epoxy resin DGEBA cured with EDA.

شيمي فيزيك

In this study, the effect of crosslinking degree an‎d MIL-53(Fe) nanoparticle size on the thermal an‎d mechanical properties of DGEBA epoxy resin cured with ethylenediamine was investigated. The main goal was to model the curing an‎d reinforcement process of epoxy with metal-organic framework nanoparticles to achieve improved mechanical performance an‎d thermal stability. MD simulation was used in the Materials Studio software environment to conduct this study. First, the initial structures of DGEBA epoxy an‎d EDA hardener were modeled in the appropriate stoichiometric ratio. Then, by using geometric optimization algorithms, alternating heating-cooling method, an‎d applying NPT an‎d NVT statistical sets, the thermal an‎d structural equilibrium of the system was achieved. The process of crosslinking between epoxy an‎d amine groups was modeled using Perl coding. Next, MIL-53(Fe) nanoparticles with different dimensions were added to the epoxy matrix as a reinforcing phase, an‎d the interactions between the nanoparticles an‎d the polymer network were investigated using the COMPASSIII force field an‎d, in some cases, UFF. After the system reached equilibrium, various properties, including glass transition temperature, Youngʹs, shear, an‎d bulk moduli, thermal expansion coefficient, free volume fraction, an‎d radial distribution functions (RDF), were calculated. The results showed that increasing the crosslinking percentage increased the mechanical moduli an‎d thermal stability, but due to the decrease in chain mobility, it caused a relative decrease in flexibility an‎d an increase in free volume. Adding MIL-53(Fe) nanoparticles in optimal amounts improved the mechanical properties an‎d Tg an‎d reduced the thermal expansion coefficient. While higher weight percentages led to a relative decrease in some properties. The results showed that nanoparticles with smaller dimensions have better efficiency in improving epoxy properties due to a larger contact surface with the matrix an‎d stronger interaction. This research shows that the appropriate selec‎tion of crosslinking percentage an‎d use of MIL-53(Fe) nanoparticles with optimal size is an effective solution for improving the mechanical an‎d thermal properties of epoxy resins.

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