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: 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.

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: 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: 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: 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: 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: An autonomic self-indicating material is provided, the material comprising a polymer composition or a composite material embedded with a microcapsule or a vascular structure comprising an aggregation-induced emission (AIE) luminogen. Upon mechanical damage to the material, the luminogen is released and aggregates, leading to fluorescence.

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 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: A microvascular system comprising a polymeric matrix and a planar structure, where the planar structure comprises a plurality of branched microfluidic channels in the matrix. At least a portion of the microfluidic channels are interconnected, and the interconnections between the channels are located in a plane defined by a longitudinal section of the planar structure.