摘要:
A UV-curable and recyclable thermoset shape memory polymer is provided. The polymer includes a vitrimer-based monomer and a photoinitiator. The vitrimer-based monomer includes a first unit rendering a high chain stiffness upon polymerization of the monomer, and a second photopolymerizable unit for photopolymerization of the monomer under a UV irradiation. The polymer has high strength, high stiffness, high recovery stress, high energy storage, reasonable recycling efficiency, and is printable using SLA with high resolution.
摘要:
A UV-curable and recyclable thermoset shape memory polymer is provided. The polymer includes a vitrimer-based monomer and a photoinitiator. The vitrimer-based monomer includes a first unit rendering a high chain stiffness upon polymerization of the monomer, and a second photopolymerizable unit for photopolymerization of the monomer under a UV irradiation. The polymer has high strength, high stiffness, high recovery stress, high energy storage, reasonable recycling efficiency, and is printable using SLA with high resolution.
摘要:
A composition comprising thermoset polymer, shape memory polymer to facilitate macro scale damage closure, and a means for molecular scale healing is disclosed; the composition has the ability to resolve structural defects by a bio-mimetic close-then heal process. In use, the shape memory polymer serves to bring surfaces of a structural defect into approximation, whereafter use of the means for molecular scale healing allowed for movement of the healing means into the defect and thus obtain molecular scale healing. The means for molecular scale healing can be a thermoplastic such as fibers, particles or spheres which are used by heating to a level at or above the thermoplastic's melting point, then cooling of the composition below the melting temperature of the thermoplastic. Compositions of the invention have the ability to not only close macroscopic defects, but also to do so repeatedly even if another wound/damage occurs in a previously healed/repaired area.
摘要:
A seismic-incurred-rupture-resistant deformation-recordable buckling-restrained brace is disclosed. A core plate is disposed in the concrete filled steel tubular outer sleeve, and an end portion of the core plate is provided with a core plate stiffening rib. A brace deformation recording device includes two toothed racks, a ratchet gear, a first cord spool, and a second cord spool. The two toothed racks are fixed on the core plate stiffening rib, and ratchet pawls in the length direction thereof face opposite directions. The ratchet gear is fixedly connected to the concrete filled steel tubular outer sleeve. The ratchet gear is disposed between the two toothed racks. A tooth on the ratchet gear is engaged with a ratchet pawl. The first cord spool is fixed on the ratchet gear. The second cord spool is fixed on the core plate stiffening rib.
摘要:
FIG. 1 is a first perspective view of a candle warmer lamp showing my new design; FIG. 2 is a second perspective view thereof; FIG. 3 is a front view thereof; FIG. 4 is a back view thereof; FIG. 5 is a left side view thereof; FIG. 6 is a right side view thereof; FIG. 7 is a top view thereof; FIG. 8 is a bottom view thereof; FIG. 9 is a perspective view of another state of the candle warmer lamp thereof; FIG. 10 is a perspective view of another state of the candle warmer lamp thereof; and, FIG. 11 is an enlarged view of the selected portion 11 in FIG. 1. The broken lines shown in the drawings depict portions of the candle warmer lamp that form no part of the claimed design.
摘要:
Disclosed herein, in accordance with some aspects of the present disclosure, are adaptive harmonic diffractive liquid crystal lenses and methods of making and use thereof.
摘要:
The low temperature cracking and high temperature rutting of polymer-modified asphalt concrete pavement can be reduced. The composite includes asphalt and at least one polymer that expands at low temperature, triggered by cooling-induced tensile stress, to reduce thermal cracking. The composite includes at least one polymer that expands at high temperature, so that the composite recovers after compression induced by traffic loading at higher temperatures, thereby reducing rutting. The system reduces thermal stress, and reduces or even eliminates thermal cracking and rutting. Shape memory polymers (SMPs) are used to improve asphalt compositions so that they better resist both thermal cracking and rutting. The SMP(s) can be incorporated into the asphalt, or a portion of fine aggregates can be replaced with SMP particles or SMP fibers, or aggregate replacement and asphalt modification can be combined. An alternative embodiment uses a standalone SMP component within an asphalt pavement, for example the form of a pre-stretched SMP grid, or a pre-stretched SMP stress-absorbing membrane, or an SMP-modified asphalt tack coat, etc., to reduce cracking and to provide reinforcement.
摘要:
A sealant composition and method for its manufacture are disclosed. A two-way shape memory polymer (2W-SMP) sealant expands upon cooling and contracts upon heating, and thus provides improved sealing for pavements and other structures. The base resin for the sealant is polybutadiene with a high cis content.
摘要:
A composition comprising thermoset polymer, shape memory polymer to facilitate macro scale damage closure, and means for molecular scale healing has the ability to repair structural defects by a bio-mimetic, close-then-heal process. The shape memory polymer serves to bring surfaces of a structural defect into proximity, after which the healing means moves into the defect and provides molecular scale healing. The means for molecular scale healing can be a thermoplastic, such as fibers, particles or spheres, which are heated to or above the thermoplastic's melting point, and then the composition is cooled below that melting temperature. The compositions can not only close macroscopic defects, but they can also do so repeatedly even if damage recurs in a previously healed/repaired area.
摘要:
9-dihydro-13-acetylbaccatin III, one of the chemicals obtained from Taxus canadensis is used to produce, inter alia, 10-decetylbaccatin III, a useful intermediate for the preparation of paclitaxel and analogues thereof The 9-dihydro-13-acetylbaccatin III is converted into the 10-deacetylbaccatin III by a simple three step process involving (a) replacement of the C-7 hydroxyl group of tho 9-dihydro compound with a protecting group, (b) the oxidizing of the C-7 protected compound to produce a C-9 ketone, and (c) the deprotecting of the C-9 ketone to produce 10-deacetylbaccatin III.