摘要:
Polymers, and particularly conventional commodity bulk polymers, are modified to have a surface activity of interest using a surface modifying polymer that includes a moiety that favors migration to the surface of the bulk polymer together with a moiety provides the activity of interest (e.g., biocidal, wettability modifying (hydrophobic or hydrophilic), resistance to radiant energy, providing a functional group for functionalizing the surface, etc.). The surface modifying polymer is combined with the bulk polymer, and, due to the presence of the moiety that favors migration, concentrates primarily on the surface of the bulk polymer such that the moiety that provides the activity of interest is located primarily on the surface of the bulk polymeric article which is produced. Advantageously, only a minimal amount (such as, e.g., about 2 weight %) of polymeric surface modifier is needed. Being able to achieve desired properties (such as biocidal activity, wettability modification, etc.) without needing much polymeric surface modifier is highly advantageous.
摘要:
A self-humidifying polymer electrolyte membrane (PEM) fuel cell assembly has an ion-exchange membrane interposed between hydrogen and oxygen diffusion layers to form a membrane electrode assembly (MEA). The MEA is in turn interposed between a pair of current collector plates having flow field channels for flowing the reactants adjacent the respective diffusion layers to produce corresponding anodic and cathodic electrochemical reactions. Various embodiments of the assembly incorporate one or more of the following features: interdigitated flow field channels, countercurrent reactant flows, opposing channel alignment, and uncatalyzed membrane hydration enhancement zones.
摘要:
This invention is directed to mono- and bis-substituted oxetane monomers having fluorinated alkoxymethylene side chains, hydroxy-terminated prepolymers derived from these mono- and bis-substituted oxetane monomers and tetrahydrofuran (THF), and polymers produced from these prepolymers, as well as the synthesis processes associated with each, and the use of the monomers, prepolymers and ultimate polymers, both directly and as components of numerous compositions.
摘要:
Fluoropolymer materials containing tetrafluoroethylene monomers, such as PTFE, are significantly swollen by supercritical carbon dioxide at high temperatures and pressures. The swollen fluoropolymer is processable by molding, extrusion, and other techniques. In addition, the fluoropolymer may be sintered at significantly lower temperatures compared to a nonswollen fluoropolymer material. The melting temperature of fluorinated polymers containing tetrafluoroethylene and triflouroethylene monomers which are swollen with supercritical carbon dioxide is significantly reduced, thereby permitting manufacturing operations such as extruding and molding to be performed at lower temperatures and with reduced risk of decomposition.
摘要:
This invention is directed to mono- and bis-substituted oxetane monomers having fluorinated alkoxymethylene side chains, hydroxy-terminated prepolymers derived from these mono- and bis-substituted oxetane monomers and tetrahydrofuran (THF), and polymers produced from these prepolymers, as well as the synthesis processes associated with each, and the use of the monomers, prepolymers and ultimate polymers, both directly and as components of numerous compositions.
摘要:
Fluoropolymer materials containing tetrafluoroethylene monomers, such as PTFE, are significantly swollen by supercritical carbon dioxide at high temperatures and pressures. The swollen fluoropolymer is processable by molding, extrusion, and other techniques. In addition, the fluoropolymer may be sintered at significantly lower temperatures compared to a nonswollen fluoropolymer material. The melting temperature of fluorinated polymers containing tetrafluoroethylene and triflouroethylene monomers which are swollen with supercritical carbon dioxide is significantly reduced, thereby permitting manufacturing operations such as extruding and molding to be performed at lower temperatures and with reduced risk of decomposition.
摘要:
Polymers, and particularly conventional commodity bulk polymers, are modified to have a surface activity of interest using a surface modifying polymer that includes a moiety that favors migration to the surface of the bulk polymer together with a moiety provides the activity of interest (e.g., biocidal, wettability modifying (hydrophobic or hydrophilic), resistance to radiant energy, providing a functional group for functionalizing the surface, etc.). The surface modifying polymer is combined with the bulk polymer, and, due to the presence of the moiety that favors migration, concentrates primarily on the surface of the bulk polymer such that the moiety that provides the activity of interest is located primarily on the surface of the bulk polymeric article which is produced. Advantageously, only a minimal amount (such as, e.g., about 2 weight %) of polymeric surface modifier is needed. Being able to achieve desired properties (such as biocidal activity, wettability modification, etc.) without needing much polymeric surface modifier is highly advantageous.
摘要:
Polymers, and particularly conventional commodity bulk polymers, are modified to have a surface activity of interest using a surface modifying polymer that includes a moiety that favors migration to the surface of the bulk polymer together with a moiety provides the activity of interest (e.g., biocidal, wettability modifying (hydrophobic or hydrophilic), resistance to radiant energy, providing a functional group for functionalizing the surface, etc.). The surface modifying polymer is combined with the bulk polymer, and, due to the presence of the moiety that favors migration, concentrates primarily on the surface of the bulk polymer such that the moiety that provides the activity of interest is located primarily on the surface of the bulk polymeric article which is produced.
摘要:
Fluoropolymer materials containing tetrafluoroethylene monomers, such as PTFE, are significantly swollen by supercritical carbon dioxide at high temperatures and pressures. The swollen fluoropolymer is processable by molding, extrusion, and other techniques. In addition, the fluoropolymer may be sintered at significantly lower temperatures compared to a nonswollen fluoropolymer material. The melting temperature of fluorinated polymers containing tetrafluoroethylene and triflouroethylene monomers which are swollen with supercritical carbon dioxide is significantly reduced, thereby permitting manufacturing operations such as extruding and molding to be performed at lower temperatures and with reduced risk of decomposition.
摘要:
Fluoropolymer materials containing tetrafluoroethylene monomers, such as PTFE, are significantly swollen by supercritical carbon dioxide at high temperatures and pressures. The swollen fluoropolymer is processable by molding, extrusion, and other techniques. In addition, the fluoropolymer may be sintered at significantly lower temperatures compared to a nonswollen fluoropolymer material. The melting temperature of fluorinated polymers containing tetrafluoroethylene and triflouroethylene monomers which are swollen with supercritical carbon dioxide is significantly reduced, thereby permitting manufacturing operations such as extruding and molding to be performed at lower temperatures and with reduced risk of decomposition.