Nanocomposites comprising biodegradable polymers and inorganic nanoparticles, methods of preparation and uses thereof

A completely dried nanocomposite comprising a polymer and an anhydrous MX2-based fullerene-like nanoparticles or nanotubes;

• wherein said polymer is selected from poly(lactic acid), poly (lactic-co-glycolic acid) or a combination thereof,
• wherein M is Mo, W, Ta or Nb;
• and X is S, Se or Te;
• wherein the weight percentage of the MX2-based fullerene-like nanoparticles or nanotubes from the total weight of said nanocomposite is between 0.25% and 3%,
• wherein the anhydrous MX2-based fullerene-like nanoparticles or nanotubes is defined as the MX2-based fullerene-like nanoparticles or nanotubes having been heated and/or vacuum annealed at a temperature of 60-200° C. for 0.5-3 hours;
• wherein the composite has at least one of the following properties:
• modulus between 1.6-4 GPa;
• toughness (area below the stress-strain curve) between 1.1-40 MPa/%;
• static friction coefficient, μs, between 0.055-0.08;
• kinetic friction coefficient, μs, between 0.02-0.05;
• yield strength:
• between 15-75 MPa;
• and friction force reduced by between 10-99% compared to the polymer alone;
• wherein the completely dried nanocomposite is prepared by:
• dissolving the polymer in a first solvent;
• dissolving the anhydrous MX2-based fullerene-like nanoparticles or nanotubes in a second solvent;
• mixing together both of the solutions;
• solvent casting the mixed solution;
• and
• drying and/or annealing the mixed solution to obtain the nanocomposite for between 48 hours to 7 days;
• between 7-10 days;
• or between 10-14 days;
• and at between 30-40° C.;
• between 40-50° C.;
• between 50-60° C.;
• or between 60-70° C.;
• and
• wherein the dissolved polymer is optionally dried prior to its dissolution step.