For promoting modifying application of sprayed polyurea (SPUA) in asphalt pavement materials, the effects materials on high-temperature and fatigue performance binders were investigated from different aspects. First, optimal preparation parameters sprayed-polyurea-modified (SPMAs) determined by designing an orthogonal test. Then, properties with contents characterized rheological testing method...

Polymers bearing dynamic covalent bonds may exhibit dynamic properties, such as self-healing, shape memory and environmental adaptation. However, most dynamic covalent chemistries developed so far require either catalyst or change of environmental conditions to facilitate bond reversion and dynamic property change in bulk materials. Here we report the rational design of hindered urea bonds (ure...

Presented here are the results of a systematic study of the viscoelastic properties of polyurea over broad ranges of strain rates and temperatures, including the high-pressure effects on the material response. Based on a set of experiments and a master curve developed by Knauss (W.G. Knauss, Viscoelastic Material Characterization relative to Constitutive and Failure Response of an Elastomer, In...

The discovery of polyurethane [PU] dates back to the year 1937 by Otto Bayer and his coworkers at the laboratories of I.G. Farben in Leverkusen, Germany. The initial works focussed on PU products obtained from aliphatic diisocyanate and diamine forming polyurea, till the interesting properties of PU obtained from an aliphatic diisocyanate and glycol, were realized. Polyisocyanates became commer...

A series of quasi-static and dynamic uniaxial compression experiments over a wide range temperatures were conducted on polyurea elastomer. The stress-strain response exhibits extreme nonlinearity, temperature strain-rate sensitivity. How to comprehensively describe these complex behaviors regulated by the unique micro-structure is still an open question. In this paper, nonlinear viscoelastic co...

Naproxen (Nap), a non-steroidal anti-inflammatory drug, and 5-fluorouracil (5FU), an anticancer were easily incorporated into polyurea xerogel. Polyureas (PUr) synthesized by one pot reaction via sol–gel chemistry. Soft segments based on polyetheramine-PEO hard hexamethylene diisocyanate trimer (HDI). The final materials characterized Fourier transform infrared (FTIR) spectroscopy, small-angle ...

Polymer materials have been used for electronic, optical and bio micro/nano devices. Polymer device fabrication technologies based on replication methods including hot embossing (Becker & Heim, 2000; Park et al., 2003; Shinohara et al., 2007b), injection molding (Becker et al., 1986; Svedberg et al., 2003), ultraviolet (UV) imprinting (Haisma et al., 1996; Kawaguchi et al., 2007; Shinohara et a...

Abstract In order to study the impact resistance of polyurea coating, a 12.7mm ballistic gun was used launch an load target plate, then velocity fragments before and after penetrating plate measured, limit specific absorption energy were calculated. At same time, combining with coating failure morphology, analyses anti-penetration effect protective under unit areal density. The research shows t...