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Nanocomposites comprising high-density polyethylene (HDPE) and boehmite (BA) nanoparticles were prepared by melt blending and subsequently irradiated with electrons. Electron irradiation of HDPE causes crosslinking and, in the presence of BA, generates ketone functional groups. The functional groups can then form hydrogen bonds with the hydroxyl groups on the surface of the BA. Additionally, if the BA is surface modified by vinyltrimethoxysilane (vBA), it can covalently bond with the HDPE by irradiation-induced radical grafting. The strong covalent bonds generated by electron beam irradiation allow the desirable properties of the nanofiller to be transferred to the rest of the nanocomposite. Since EB irradiation produces a great number of strong covalent bonds between vBA nanoparticles and HDPE, the modulus of elasticity, yield strength, and resistance to thermal shrinkage are enhanced by electron irradiation.

Nylon-6 (PA6) nanofiber webs incorporated with boehmite nanoparticles as an electrostatic charging agent were electrospun and their fiber morphology was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM showed that the median fiber diameter of the PA6 nanofibers was 73 nm and boehmite nanoparticles had little effect on the fiber diameter. The filtration performance of the nanofiber web was measured using 0.3 micron DOP aerosols at a 5.3 cm/s face velocity. Processed and corona charged PA6 nanofiber web showed significant improvement in the submicron aerosol capture efficiency without a change in the air flow resistance compared to the discharged nanofiber web. These results suggest that the electrospinning process imparted electrostatic charge efficiently on the PA6 nanofiber web, and the electrostatic surface potential of a nanofiber web is increased with the incorporation of boehmite nanoparticles. [ABSTRACT FROM AUTHOR]

Nanocomposites comprising high-density polyethylene (HDPE) and boehmite (BA) nanoparticles were prepared by melt blending and subsequently irradiated with electrons. Electron irradiation of HDPE causes crosslinking and, in the presence of BA, generates ketone functional groups. The functional groups can then form hydrogen bonds with the hydroxyl groups on the surface of the BA. Additionally, if the BA is surface modified by vinyltrimethoxysilane (vBA), it can covalently bond with the HDPE by irradiation-induced radical grafting. The strong covalent bonds generated by electron beam irradiation allow the desirable properties of the nanofiller to be transferred to the rest of the nanocomposite. Since EB irradiation produces a great number of strong covalent bonds between vBA nanoparticles and HDPE, the modulus of elasticity, yield strength, and resistance to thermal shrinkage are enhanced by electron irradiation. [ABSTRACT FROM AUTHOR]

• A gradient-enhanced damage model for epoxy nanocomposites was developed. • A nonlocal constitutive description for the nanocomposites was parameterized. • The constitutive model was integrated into a nonlinear finite element analysis. • The numerical framework for predicting damage and fracture processes was validated. To analyze the experimentally observed failure process in nanoparticle/polymer nanocomposites, a variety of factors, including nonlocal characteristics of damage mechanism and nonlinear viscoelasticity, are required to be investigated. This work presents the development and numerical implementation of a finite deformation gradient-enhanced damage model for boehmite nanoparticle (BNP)/epoxy nanocomposites. The parameters identification of the nonlocal constitutive description is realized using a framework based on molecular simulations and experimental tests. In this context, molecular simulations are performed to parameterize the Argon model of viscoelasticity, while damage and nonlocal parameters are determined using experimental data obtained from compact-tension tests. The nonlocal constitutive model integrated into a nonlinear FE analysis is validated by comparing the numerical results of compact-tension tests of BNP/epoxy samples with experimental data. The experimental–numerical validation confirms the predictive capability of the modeling framework. The proposed procedure can be extended to other types of nanoparticle reinforced thermosetting polymers. [ABSTRACT FROM AUTHOR]