Abstract: PU/ZnO nanocomposites are provided wherein the addition of less than 1 vol % 33 nm ZnO nanoparticles into a PU matrix effect a decrease in the Young's Modulus and storage modulus of the polymer, while simultaneously effecting an increase glass transition temperature of the polymer. Detailed experiments are described (e.g., FTIR, DMTA, FESEM and AFM) that suggest that the reaction between hydroxyl groups of the ZnO nanoparticles and isocyanate groups of the polyurethane prepolymer disrupts the self-assembly of the phase separation in PU. Phase separation is responsible for the good mechanical properties of PU. Further, detailed experiments suggest that the increase of the glass transition temperature results from the crosslinking effect of the ZnO nanoparticles.

Abstract: A method and system for forming a polymer nanocomposite. A peroxide-degradable polymer, a clay, and a peroxide are mixed to form a polymer-clay-peroxide mixture. The polymer-clay-peroxide mixture is then heated forming a polymer-clay-peroxide melt containing peroxide radicals. The result is a degradation of the peroxide-degradable polymer within the melt to form smaller molecular weight polymer chains using the peroxide radicals and a diffusion of said polymer chains into the clay within the melt so as to exfoliate the clay to form the polymer nanocomposite having exfoliated clay being randomly dispersed throughout the polymer nanocomposite.

Abstract: PU/ZnO nanocomposites are provided wherein the addition of less than 1 vol % 33 nm ZnO nanoparticles into a PU matrix effect a decrease in the Young's Modulus and storage modulus of the polymer, while simultaneously effecting an increase glass transition temperature of the polymer. Detailed experiments are described (e.g., FTIR, DMTA, FESEM and AFM) that suggest that the reaction between hydroxyl groups of the ZnO nanoparticles and isocyanate groups of the polyurethane prepolymer disrupts the self-assembly of the phase separation in PU. Phase separation is responsible for the good mechanical properties of PU. Further, detailed experiments suggest that the increase of the glass transition temperature results from the crosslinking effect of the ZnO nanoparticles.

Abstract: A method and system of forming a polymer nanocomposite. A layered clay and polymer are selected wherein |Sp?Sscf|>|Sc?Sscf| and |Sc?Sscf|?2.0 (cal/cm3)0.5 are satisfied. Sp, Sc, and Sscf is a solubility parameter of the polymer, clay, and a supercritical fluid (SCF), respectively. The polymer and clay are mixed to form a polymer-clay mixture. The polymer-clay mixture is melted to form a polymer-clay melt. The polymer-clay melt is initially contacted with the SCF while the SCF is subject to an initial pressure exceeding the critical pressure of the SCF and to a temperature exceeding the critical temperature of the SCF. The polymer-clay melt is further contacted with the SCF while the SCF is at a lower pressure below the critical pressure of the SCF to exfoliate the clay to form the nanocomposite having the exfoliated clay being substantially dispersed throughout the polymer of the polymer-clay.