An epoxy based on the diglycidyl ether of bisphenol A (DGEBA) has been modified with poly(phenylene oxide) (PPO) and cured with piperidine. A two-phase alloy resulted, in which the DGEBA epoxy was the continuous phase. Several PPO loadings were investigated. The tensile yield strengths of these PPO-modified epoxies were found to be independent of PPO content. In contrast, the fracture toughness...

Biological materials possess a variety of artful interfaces whose size and properties are adapted to their hierarchical levels and functional requirements. Bone, nacre, and wood exhibit an impressive fracture resistance based mainly on small crystallite size, interface organic adhesives and hierarchical microstructure. Currently, little is known about mechanical concepts in macroscopic biologic...

Two-dimensional Finite Element Method simulations, which involve consideration of the nonlinearity of a material, have been conducted to gain understanding about the rigid-rigid polymer toughening concept we proposed. The simulation results for the plane stress condition indicate that as long as the inclusion phase possesses i) a 60% difference in the tangent modulus from that of the matrix at ...

Flexible electronic technology has developed rapidly in recent years, showing broad application prospects motion monitoring, wearable devices, and personalized medicine. Consequently, the demand for high sensitivity wide sensing range gradually increased. Conductive hydrogels have flexibility, excellent conductivity, good biocompatibility, making them ideal candidates fabricating flexible senso...

This letter discusses the effect of bonding energy on the delamination resistance of laminate composites using a ductile interleaf. The mechanism and methods for interleaf toughening are reviewed and the improvement in delamination resistance discussed. The bonding energy between the ductile interleaf polymer and the fibers as well as between the ductile interleaf polymer and the brittle matrix...

Inspired by the nacre, we demonstrated the integrated ternary artificial nacre nanocomposites through synergistic toughening of graphene oxide (GO) and nanofibrillar cellulose (NFC). In addition, the covalent bonding was introduced between adjacent GO nanosheets. The synergistic toughening effects from building blocks of one-dimensional NFC and two-dimensional GO, interface interactions of hydr...

Ambientto elevated-temperature fracture and fatigue-crack growth results are presented for five MoMo3Si-Mo5SiB2–containing -Mo matrix (17 to 49 vol pct) alloys, which are compared to results for intermetallic-matrix alloys with similar compositions. By increasing the -Mo volume fraction, ductility, or microstructural coarseness, or by using a continuous -Mo matrix, it was found that improved fr...