Effects of gamma radiation on nanocomposite films of polycaprolactone with modified MCM-48

Abstract

The aim of this investigation was to assess the effects of gamma radiation on nanocomposite films (NC films) formed by PCL (polycaprolactone) with MCM-48 nanoparticles (PCL/MCM-48) and PCL with MCM-48 NPs modified with (3-aminopropyl)triethoxysilane (APTES) (PCL/MCM-48-NH 2 ). The nanocomposite films were obtained using the solvent casting method. After preparing the films, they were irradiated at 25 kGy in the presence of air and analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), transmission electronic microscopy (TEM), as well as for their mechanical properties. The exposure of NC films to gamma radiation at 25 kGy did not cause major changes in either thermal or mechanical properties such as tensile strength and modulus of elasticity. The results revealed that gamma radiation was a successful choice for the sterilization of these materials.

Gamma radiation effect on the chemical, mechanical and thermal properties of PCL/MCM-48-PVA nanocomposite films

“…It also showed mass loss events between 200 °C and 600 °C, which are described as the elimination of organic content, which corroborates that the surface of MCM-48 was modified with PVA. These results are in agreement with our previous study: where the surface of MCM-48 was modified with APTES, it was observed that modified MCM-48 had a first event close to 100 °C attributed to the elimination of water; and a second event which was assigned to the surface modification with APTES [ 35 ]. Pure PVA had a first mass loss between 60 °C and 200 °C originating from the loss of adsorbed water [ 53 ].…”

“…Table 2 shows that the T 5 , T 10 , T 50 , and T max values for F2 and F5 were similar before and after exposure at 25 kGy. These results are similar to those shown in our previous study for T 5 , T 10 , and T 50 for PCL/MCM-48 films irradiated at 25 kGy [ 35 ]. TGA data demonstrated that the thermal decomposition characteristics of F2 practically did not differ from the thermal decomposition characteristics exhibited by F5.…”

“…The samples exhibited a single mass loss event between 200 and 500 °C, this event was associated with the decomposition of the PCL [ 56 , 57 ]. This thermal behavior was similar to that observed for PCL in our previous study, revealing that the thermal stability of the polymer is preserved after the insertion of MCM-48-M and irradiated at 25 kGy [ 35 ]. The absence of mass loss events characteristic of the thermal decomposition of MCM-48 such as loss of water adsorbed was attributed to the low content of MCM-48 in the PCL matrix, however the presence of MCM-48-M in NC films was confirmed by SEM and TEM images (Sections 3 , 3.5 .6).…”

“…Similarly, Mallakpor and Nouruzi modified ZnONPs with PVA to obtain NC films with PCL, observing that the modified ZnONPs with PVA showed desirable dispersion in the PCL matrix [ 34 ] . Paula et al carried out surface modification of MCM-48 with (3-Aminopropyl)triethoxysilane (APTES) into the PCL matrix to obtain NC films, achieving positive distribution in the PCL matrix [ 35 ] . Lopez-Figueras et al prepared PCL/MCM-41 composites functionalized with N -[3-(trimethoxysilyl)propyl]-ethylenediamine (EPTES) via in situ polymerization that exhibited better thermal properties, ascribed to the interaction between PCL and the MCM-41-EPTES [ 11 ].…”

“…PCL NCs are used in biomaterials and food packaging [ 35 , 37 ], but require the sterilization of materials to eliminate microorganisms through exposure to gamma radiation at 25 kGy - considered the gold standard to eliminate microorganisms [ 38 ] . Exposure of PCL NCs to gamma radiation can compromise their tensile properties and chemical characteristics [ 39 ].…”