Abstract: A method of spontaneously patterning a polymer during frontal polymerization includes activating an initiation region of a monomer solution to reaction to initiate a polymerization reaction. A polymerization front is generated and propagates through the monomer solution in a radial or longitudinal direction away from the initiation region. The monomer solution is spontaneously heated downstream of the polymerization front by thermal transport away from the polymerization reaction. Once a localized region of the monomer solution reaches a temperature sufficient for spontaneous initiation of another polymerization reaction, a new polymerization front is generated and propagates through the monomer solution in a circumferential or transverse direction.

Abstract: Methods of preparing oligomers including heating a mixture of an amount of a functionalized cycloalkene, an amount of a chain transfer agent, a phosphite ester, and a catalyst, a degree of polymerization of the oligomers controllable by a molar ratio of the amount of the functionalized cycloalkene to the amount of the chain transfer agent, are provided herein. Methods of preparing polymers including heating the oligomers and a second amount of the functionalized cycloalkene, a phosphite ester, and a catalyst are further provided. Compositions of oligomers and functionalized cycloalkenes are further provided.

Abstract: A frontally polymerized polymeric body includes, according to a first embodiment, a deformable polymer comprising polydicyclopentadiene (pDCPD) and/or poly(5-ethylidene-2-norbornene) (pENB), where the deformable polymer has a fracture strain of at least about 0.5 mm mm?1. According to a second embodiment, the frontally polymerized polymeric body includes a first polymer comprising pDCPD and/or pENB, and a second polymer adjacent to the first polymer also comprising the pDCPD and/or the pENB. The second polymer is more or less deformable than the first polymer. Thus, the frontally polymerized polymeric body exhibits spatially varying mechanical and/or other properties.

Abstract: A method of light-promoted frontal ring-opening metathesis polymerization includes providing a monomer solution including dicyclopentadiene, a ruthenium-based catalyst and a phosphite inhibitor, and exposing the monomer solution to ultraviolet light having a wavelength in a range from 315 nm to 400 nm, thereby initiating an exothermic polymerization reaction and generating a self-propagating polymerization front. The polymerization front moves through the monomer solution and polymerizes the dicyclopentadiene.

Abstract: A method of rapidly forming an elastomer with tunable properties is described herein. The method includes preparing a monomer solution comprising a catalyst and one or more monomers including 1,5-cyclooctadiene (COD). The one or more monomers may further include dicyclopentadiene (DCPD), and each of the COD and the DCPD may be present in the monomer solution at a predetermined volume percentage. A region of the monomer solution is activated to initiate an exothermic polymerization reaction and generate a self-propagating polymerization front, which moves through the monomer solution and polymerizes the one or more monomers. Thus, an elastomer having predetermined properties is rapidly formed.

Abstract: A frontally polymerized polymeric body includes, according to a first embodiment, a deformable polymer comprising polydicyclopentadiene (pDCPD) and/or poly(5-ethylidene-2-norbornene) (pENB), where the deformable polymer has a fracture strain of at least about 0.5 mm mm?1. According to a second embodiment, the frontally polymerized polymeric body includes a first polymer comprising pDCPD and/or pENB, and a second polymer adjacent to the first polymer also comprising the pDCPD and/or the pENB. The second polymer is more or less deformable than the first polymer. Thus, the frontally polymerized polymeric body exhibits spatially varying mechanical and/or other properties.

Abstract: A method of forming a void, channel and/or vascular network in a polymeric matrix comprises providing a pre-vascularized structure that includes a matrix material and a sacrificial material embedded in the matrix material in a predetermined pattern, where the matrix material comprises a monomer and the sacrificial material comprises a polymer. A region of the matrix material is activated to initiate an exothermic polymerization reaction and generate a self-propagating polymerization front. As the polymerization front propagates through the matrix material and polymerizes the monomer, heat from the exothermic reaction simultaneously degrades the sacrificial material into a gas-phase and/or liquid-phase byproduct. Thus, one or more voids or channels having the predetermined pattern are rapidly formed in the matrix material.

Abstract: A method of light-promoted frontal ring-opening metathesis polymerization includes providing a monomer solution including dicyclopentadiene, a ruthenium-based catalyst and a phosphite inhibitor, and exposing the monomer solution to ultraviolet light having a wavelength in a range from 315 nm to 400 nm, thereby initiating an exothermic polymerization reaction and generating a self-propagating polymerization front. The polymerization front moves through the monomer solution and polymerizes the dicyclopentadiene.

Abstract: The corrosion of unprotected steel substrates causes damage that is costly to repair or replace. Current protective coatings predominately rely on environmentally harmful anticorrosive agents and toxic solvents to protect the underlying substrate. The use of lawsone (2-hydroxy-1,4-napthoquinone) together with a environmentally benign epoxy coating provides an environmentally-friendly alternative for common protective coatings. Microencapsulated lawsone embedded coatings allows the anticorrosive agent to remain dormant until released by damage and is then deposited directly onto the steel substrate. Both visual and electrochemical analysis shows that this self-protective scheme leads to 60% corrosion inhibition in a neutral salt water solution.

Abstract: A partially degradable polymeric fiber includes a thermally degradable polymeric core and a coating surrounding at least a portion of the core. The thermally degradable polymeric core includes a polymeric matrix including a poly(hydroxy-alkanoate), and a metal selected from the group consisting of an alkali earth metal and a transition metal, in the core polymeric matrix. The concentration of the metal in the polymeric matrix is at least 0.1 wt %. The partially degradable polymeric fiber may be used to form a microvascular system containing one or more microfluidic channels.

Abstract: The present disclosure provides a composition of matter comprising purified cyclic poly(phthalaldehyde) (cPPA) and a plasticizer. The composition enables thermal processing and molding in bulk quantities, and is designed to degrade when contacted by an acid or exposed to a high enough temperature. Photodegradable cPPA containing a photooxidant is disclosed. Methods of making and recycling the composition of matter are also provided.

Abstract: The present disclosure provides a novel method of 3D printing using frontal polymerization chemistry. This method enables the printing of tough, high quality thermosets in a short time with the option of adding fiber reinforcement. As such, it facilitates fabrication of mechanically robust 3D-printed devices and structures.

Abstract: The present disclosure provides a novel method of 3D printing using frontal polymerization chemistry. This method enables the printing of tough, high quality thermosets in a short time with the option of adding fiber reinforcement. As such, it facilitates fabrication of mechanically robust 3D-printed devices and structures.

Abstract: A microvascular system includes a solid polymeric matrix and a woven structure in the matrix. The woven structure includes a plurality of fibers, and a plurality of microfluidic channels, where at least a portion of the microfluidic channels are interconnected. The microvascular system may be made by forming a composite that includes a solid polymeric matrix and a plurality of sacrificial fibers in the matrix, heating the composite to a temperature of from 100 to 250° C., maintaining the composite at a temperature of from 100 to 250° C. for a time sufficient to form degradants from the sacrificial fibers, and removing the degradants from the composite. The sacrificial fibers may include a polymeric fiber matrix including a poly(hydroxyalkanoate) and a metal selected from the group consisting of an alkali earth metal and a transition metal, in the fiber matrix, where the concentration of the metal in the fiber matrix is at least 0.1 wt %.

Abstract: A thermally degradable polymeric sheet, comprising: a poly(hydroxyalkanoate); and a metal selected from the group consisting of an alkali earth metal and a transition metal; where the volume fraction of the metal in the sheet is at least 0.1 vol %.

Abstract: A method of forming a void, channel and/or vascular network in a polymeric matrix comprises providing a pre-vascularized structure that includes a matrix material and a sacrificial material embedded in the matrix material in a predetermined pattern, where the matrix material comprises a monomer and the sacrificial material comprises a polymer. A region of the matrix material is activated to initiate an exothermic polymerization reaction and generate a self-propagating polymerization front. As the polymerization front propagates through the matrix material and polymerizes the monomer, heat from the exothermic reaction simultaneously degrades the sacrificial material into a gas-phase and/or liquid-phase byproduct. Thus, one or more voids or channels having the predetermined pattern are rapidly formed in the matrix material.

Abstract: Autonomous detection of damage in a polymer coating is described by utilizing microcapsules in a polymer coating having free and/or residual amines. The microcapsules contain a color indicator, such as 2?,7?-dichlorofluorescein (DCF), bromophenol blue (BPB) or fluorescamine, which is reactive with the free and/or residual amines present in the polymer coating. For coatings without the presence of free and/or residual amines, a color indicator microcapsule can be combined with a second type of microcapsule filled with a base. When sufficient damage is inflicted to the coating, the microcapsules in and/or around an area of the damage will rupture, and the color indicator will react with the free and/or residual amines or the base to autonomically indicate the area in which the coating has been damaged.

Abstract: Autonomic cooling of a substrate is achieved using a porous thermal protective layer to provide evaporative cooling combined with capillary pumping. The porous thermal protective layer is manufactured onto the substrate. A vascular network is integrated between the substrate and the protective layer. Applied heat causes fluid contained in the protective layer to evaporate, removing heat. The fluid lost to evaporation is replaced by capillary pressure, pulling fluid from a fluid-containing reservoir through the vascular network. Cooling occurs as liquid evaporates from the protective layer.

Abstract: Photo-protected microcapsules containing a photopolymer composition are dispersed in an epoxy coating to form an autonomic self-healing material. The capsule shell wall is formulated to protect the photopolymer composition from electromagnetic radiation exposure prior to rupture of the capsule shell, so that the photopolymer composition (e.g., a UV curable epoxy resin) remains active until triggered by damage to the capsule shell. Carbon black pigment is a suitable UV protector for the capsules. Upon sufficient damage to a region of the coating, the capsules will rupture and the photopolymer composition will fill and cure in and/or around the damaged region in the presence of electromagnetic radiation, achieving autonomic healing of the damaged coating.

Abstract: Polydicyclopentadiene (PDCPD) is a polymer of growing importance in industrial applications. Frontal ring-opening metathesis polymerization (FROMP) offers a means to rapidly cure PDCPD with minimal input energy owing to a propagating reaction wave sustained by the exothermic polymerization. The disclosure provides methods for the rapid fabrication of fiber reinforced composites that is less restrictive and more energy efficient than conventional methods.