We compare and contrast the microstructure, viscoelastic properties, and shock response of coarse-grained models of multiblock copolymer and diblock copolymers using molecular dynamics simulations. This study is motivated by the excellent dissipative and shock-mitigating properties of polyurea, speculated to arise from its multiblock chain architecture. Our microstructural analyses reveal that ...

BACKGROUND Polyurea crosslinked silica aerogels are highly porous, lightweight, and mechanically strong materials with great potential for in vivo applications. Recent in vivo and in vitro studies have demonstrated the biocompatibility of this type of aerogel. The highly porous nature of aerogels allows for exceptional thermal, electric, and acoustic insulating capabilities that can be taken ad...

The rheological properties of lithium grease and polyurea at different temperatures consistencies were determined with a rotary rheometer. plateau moduli the greases calculated, mechanism influence consistency temperature on was explained. tribological wear two measured by high-temperature friction tester. mechanisms are probed lubricating grease. results show that modulus GN can be used to ass...

This study aims to solve the icing problem of wind turbine blades in low-temperature environments and improve power generation efficiency turbines. In this study, modified TiO2 particles (500 nm), butyl acetate solvent, polyaspartic acid ester polyurea (PAE polyurea), Crestron N75 curing agent were mixed sprayed on epoxy resin board surface. Static test, dynamic wear resistance adhesion strengt...

Typically, polyurea is a polymer forming microphase-separated structures. Various coarse-grained (CG) simulation models have been developed to study the microphase structure and viscoelastic properties of polyurea. However, since hydrogen atoms were modelled implicitly in existing CG models, anisotropic bonding between urea groups hard domain might not be treated properly. Here, we introduce hy...

In this work, the material properties of a series of fly ash/polyurea composites were studied. Dynamic mechanical analysis was conducted to study the effect of the fly ash volume fraction on the composite’s mechanical properties, i.e., on the material’s frequencyand temperature-dependent storage and loss moduli. It was found that the storage and loss moduli of the composite both increase as the...

Polyurea is a special type of elastomer that features fast setting time as well as good chemical and fire resistance. It has also good mechanical properties such as its high toughness-to-density ratio and high strain rate-sensitivity, so its application is recently extended to structural purpose to form sandwich-type or multi-layered plates. Those structures can be used for retrofitting of mili...

A novel class of polyurethane-polyurea nanoparticles (PUUa NPs) to install multifunctionality on biomaterials is presented. Biofunctionalization of titanium with roxithromycin loaded RGD-decorated PUUa NPs results in an outstanding improvement of osteoblast adhesion and strong suppression of bacterial attachment. This strategy represents a powerful approach to enhance the osseointegration of im...

The Glass Fiber-Reinforced Polyurea (GFRPU) which is the composite by elastic polyurea and milled glass fiber have mechanical characteristics to enhance tensile strength as well ductility. It must be reinforcement materials in repair retrofit applications for strengthening structural capacity has a merit of simple construction spray coating prevent debonding from concrete surfaces unlike existi...