Polycaprolactone/Polyhedral Oligomeric Silsesquioxane Hybrid Organic/Inorganic Nanocomposites: Mechanical and Nanomechanical Analyses

Thermoset hybrid organic/inorganic nanocomposites were fabricated using multifunctional methacrylated polyhedral oligomeric silsesquioxane (POSS-MA) nanofiller dispersed in a matrice made of polycaprolactone diacrylate (PCLA). Nanocomposites were prepared via photo-crosslinking of uniform mixtures of POSS-MA (0, 2, 10, and 30 %w/w). Mechanical properties of the nanocomposites were investigated comparing with neat samples by diametral tensile strength (DTS) and flexural strength (FS) analyses. It can be concluded that the higher POSS-MA content, the more increase in the modulus (from 17.834 to 192.743 MPa) and strength at break (from 0.8731 to 2.2483 MPa). Failure mode was also significantly impressed by POSS content. At lower nanoparticle contents, strain at break does not change remarkably (0.3789, 0.3406 and 0.3308 mm/mm for 0, 2 and 10% w/w nanoparticle respectively), but a significant shift (0.2119 mm/mm) was observed for 30% w/w POSS-MA containing samples. Nanomechanical analyses were performed in nanoindentation and nanoscratch mode under AFM using a Berkovich tip. The higher content of the reactive nanofiller causes an increase in hardness. Maximum indentation depth (hmax) decreased from 435.68 to 271.98 nm for samples containing 0 to 30% w/w POSS-MA. Mentioned characteristics do not change regularly and there is an optimum percentage for POSS-MA content in the mixture to provide the desirable mechanical properties.

کلیدواژه ها:

Nanocomposite ، Hybrid Organic-Inorganic ، Mechanical Properties ، Nanomechanical Analysis