Nanoparticle reinforcement is a general approach toward the strengthening of elastomer nanocomposite in large-scale applications. Extensive studies and efforts have been contributed to demonstrating the property reinforcement of polymer nanocomposites in relation to matrix-filler and filler-filler interaction. Here, a facile synthetic method is creatively reported to synthesize SiO 2,15/120 - g -polyisoprene (SiO 2 - g -PI) particle brushes using atom transfer radical polymerization (ATRP). The dispersion and microstructures of the nanoparticles in the nanocomposites are investigated by morphological characterizations, whereas the reinforcing mechanism is studied through mechanical measurements as well as computational simulation. Remarkably, compared with the cured bulk elastomers and matrix(M)/SiO 2 blends, M/particle brushes (PB) exhibit significant improvement in mechanical properties, including tensile strength, elongation at break, modules, and rolling resistance. This elastomer nanocomposites afford a novel prospect for the practical application of next-generation automobile tires with enhanced performance.
An efficient method for the preparation of polymer grafted gibbsite nanoplatelets (NPs) was proposed by direct preparation of initiator-tethered gibbsite (gibbsite-Br) NPs followed by surface-initiated atom transfer radical polymerization (SI-ATRP) to obtain gibbsite particle brushes. By adding portion of water-soluble solvent (e.g., alcohol), individual ATRP initiator-tethered gibbsite NPs were fabricated using 2-bromo-2-methylpropionic acid as a tetherable initiator avoiding the aggregation of gibbsite NPs which are ready for polymer grafting process. To verify the efficiency of the tethered initiator, various polymers grafted gibbsite NPs were fabricated by SI-ATRP. The results indicated that initiator anchored gibbsite NPs and various gibbsite-g-polymers (e.g., gibbsite-g-poly2-(dimethylamino) ethyl methacrylate, gibbsite-g-polyacrylonitrile, gibbsite-g-polymethyl methacrylate) were synthesized successfully. The thermal stabilities of gibbsite-g-polymer hybrid materials have been enhanced significantly. Compared with PMMA matrix, the fire-retardant behavior of gibbsite-g-polymethyl methacrylate was strengthened due to the incorporation of gibbsite NPs. This work proposed a versatile and convenient method for producing initiator-immobilized solid NPs and polymer grafts, which thereby enables promised properties of polymer hybrid materials depending on the orientation and interactions of particle brushes.
Aminated n-HAP-g-polyacrylonitrile (n-HAP-g-APAN) particle brushes were developed for highly efficient heavy metal removal based on surface-initiated ATRP (SI-ATRP) and subsequent amination. An efficient one-step method for morphology controlled synthesis of ATRP initiator immobilized n-HAP (n-HAP-Br) was realized by using 2-bromoisobutyric acid as tetherable initiator. Uniform and individually dispersed n-HAP-Br NCs were obtained with controlled morphology and particle size by adding portion of water miscible organic solvents to rational adjusting aqueous dispersion medium. Aminated n-HAP-g-APAN displayed record-high adsorption capacity of heavy meatal ions due to the combined contributions of grafted APAN providing pendent amino diethylenepentamine as chelating groups and n-HAP core towards heavy metal ions (pure n-HAP of q e = 284.4 mg/g vs n-HAP-g-APAN of q e = 944.4 mg/g). The proposed one-step direct bromination of n-HAP strategy provides the preparation of uniform n-HAP NCs ready for polymer grafting and further fabrication of n-HAP-g-polymers via SI-ATRP for various applications depending on the characteristic of grafted polymers.
危险品化学品经营许可证（带存储）