Research in urethane-acrylate UV-curables has shown that these materials have mechanical properties inferior to those of thermoplastic polyurethanes with very similar composition owing to the high cross-link density in UV-curables; in particular, their ultimate extension is low (less than 100%). Past attempts a t increasing the ultimate extension involved compromising the advantages of the UV-c...

in order to prepare polyurethane elastomers with acceptable physical properties and good biocompatibility, novel polyurethane networks were synthesized via curing reaction of epoxy-terminated polyurethane prepolymers (eups) with hexamethylene diamine. eups were prepared from reaction of glycidol with nco-terminated polyurethanes (itps). itps were also synthesized from reaction of one equivalent...

The large strain nonlinear stress-strain behavior of thermoplastic polyurethanes (TPUs) exhibits strong hysteresis, rate dependence and softening. Thermoplastic polyurethanes are copolymers composed of hard and soft segments. The hard and soft segments phase separate to form a microstructure of hard and soft domains typically on a length scale of a few tens of nanometers. Studies have revealed ...

In this work, 5,6,7,8-Tetrabromo-2,3-dihydro-2,3-bis(2-hydroxyethyl)phthalazine-1,4-dione is synthesized by the reaction of 5,6,7,8-tetrabromo-2,3-dihydrophthalazine-1,4-dione with 2-bromoethanol in the presence of triethylamine. The obtained monomer was polymerized with different diisocyanates, including hexamethylenediisocyanate (HMDI), tolylene-2,4-diisocyanate (TDI), isophoronediisocyanate ...

Polyurethanes have been broadly used as biomaterials in tissue repair and regeneration due to their preeminent biocompatibility mechanical properties. However, traditional polyurethanes are not able efficiently cope with the complexity of dynamic microenvironments during process disease therapy. Physiologically responsive responding or reacting biological signals pathological abnormalities can ...

The design of “smart” coatings and structural materials continue to offer immense promise in many emerging technologies ranging from self-healing coatings to stimuli-responsive drug delivery vehicles. Significant advances demand integration across length scales, ranging from non-covalent interactions and self-assembly at the nanometer dimension to the engineering and fabrication of functional d...

As petroleum feedstocks start to dwindle, it is becoming more important to find acceptable replacements for materials made from these feedstocks. Polyurethanes have classically been synthesized from petroleum-based feedstocks, and depending on its properties, polyurethanes can be used in everything from foams, to construction plastics. In recent years there has been an increasing amount of rese...

In many areas of application of conventional non-degradable cross-linked polyurethanes (PUR), there is a need for their degradation under the influence of specific environmental factors. It is practiced by incorporation of sensitive to degradation compounds (usually of natural origin) into the polyurethane structure, or by mixing them with polyurethanes. Cross-linked polyurethanes (with 10 and ...