摘要:
Performance additives in high performance polymers using polyhedral oligomeric silsesquioxanes (POSS) and polyhedral oligomeric silicates (POS) as nanoscopic reinforcements, porosity control agents, thermal and oxidative stability aids to improve the properties of the polymers.
摘要:
This invention teaches the preparation and compositions of POSS nanostructured chemicals bearing a variety of onium-type surfactants. The surfactants serve as low-cost compatibilizing groups for polyhedral oligomeric silsesquioxane and polyhedral oligomeric silicate nanostructures with man-made polymer and biological systems. Variations of the surfactants also provide reactivity for the nanostructured chemicals with man-made and biological materials. The surfactant bearing nanostructured chemicals are useful as alloying agents is for controlling the structure and bulk physical properties of materials from the nanoscopic length scale. Alternately, the surfactants can be eliminated from the nanostructures to render the formation of nanoscopically dispersed silica particles.
摘要:
A method of using nanostructured chemicals as alloying agents for the reinforcement of flouropolymer microstructures, including polymer coils, domains, chains, and segments, at the molecular level. Because of their tailorable compatibility with fluorinated polymers, nanostructured chemicals can be readily and selectively incorporated into polymers by direct blending processes. Properties most favorably improved are time dependent mechanical and thermal properties such as heat distortion, creep, compression set, shrinkage, modulus, hardness and abrasion resistance. In addition to mechanical properties, other physical properties are favorably improved, including lower thermal conductivity, fire resistance, and improved oxygen permeability. These improved properties may be useful in a number of applications, including space-survivable materials and creep resistant seals and gaskets. Improved surface properties may be useful for applications such as anti-icing or non-wetting surfaces or as low friction surfaces.
摘要:
The nanoscopic dimensions of polyhedral oligomeric silsesquioxanes (POSS) and polyhedral oligomeric silicates (POS) materials ranges from 0.7 nm to 5.0 nm and enables the thermomechanical and physical properties of polymeric materials to be improved by providing nanoscopic reinforcement of polymer chains at a length scale that is not possible by physically smaller aromatic chemical systems or larger fillers and fibers. A simple and cost effective method for incorporating POSS/POS nanoreinforcements onto polymers via the reactive grafting of suitably functionalized POSS/POS entities with polymeric systems amenable to such processes is described. The method teaches that the resulting POSS-grafted-polymers are particularly well suited for alloying agents by nongrafted POSS entitles such as molecular silicas. The successful alloying of POSS-polymers is aided because their interfacial tensions are reduced relative to non-POSS containing systems.
摘要:
Processes have been developed for the manufacture of polyhedral oligomeric silsesquioxanes (POSS), polysilsesquioxanes, polyhedral oligomeric silicates (POS), and siloxane molecules bearing reactive ring-strained cyclic olefins (e.g. norbornenyl, cyclopentenyl, etc. functionalities). The preferred manufacturing processes employ the silation of siloxides (Si—OA, where A=H, alkaline or alkaline earth metals) with silane reagents that contain at least one reactive ring-strained cyclic olefin functionality [e.g., X3-ySi(CH3)y(CH2)2 where y=1-2 and X=OH, Cl, Br, I, alkoxide OR, acetate OOCR, peroxide OOR, amine NR2, isocyanate NCO, and R]. Alternatively, similar products can be prepared through hydrosilation reactions between silanes containing at least one silicon-hydrogen bond (Si—H) with ring-strained cyclic olefin reagents [e.g., 5-vinyl, 2 norbornene CH2═CH, cyclopentadiene]. The two processes can be effectively practiced using polymeric silsesquioxanes [RSiO1.5]∞ where ∞=1-1,000,000 or higher and which contain unreacted silanol or silane groups at chain terminus or branch points, on POSS nanostructures of formulas [(RSiO1.5)n]Σ#, homoleptic, [(RSiO1.5)m(R′SiO1.5)n]Σ#, heteroleptic, and {(RSiO1.5)m(RXSiO1.0)n}Σ#, functionalized heteroleptic nanostructures, on silanes RSiX3, linear, cyclic, oligomeric and polymeric siloxanes (polymeric formula RX2Si—(OSiRX)m—OSiRX2 where m=0-1000, X=OH, Cl, Br, I, alkoxide OR, acetate OOCR, peroxide OOR, amine NR2, isocyanate NCO, and R). Each of the processes result in new chemical species bearing one or more ring strained olefins that can undergo polymerization, grafting, or other desirable chemical reactions to form polymeric products. These polymeric systems are most desirably utilized in polymerizations for the modification of properties of thermoplastic or thermoset resin systems or for the preparation of polymers with utility in electronics, medical devices, sporting goods, and aerospace as coatings and structural components.
摘要:
A method of using nanostructured chemicals as alloying agents for the reinforcement of polymer microstructures, including polymer coils, domains, chains, and segments, at the molecular level. Because of their tailorable compatibility with polymers, nanostructured chemicals can be readily and selectively incorporated into polymers by direct blending processes. The incorporation of a nanostructured chemical into a polymer favorably impacts a multitude of polymer physical properties. Properties most favorably improved are time dependent mechanical and thermal properties such as heat distortion, creep, compression set, shrinkage, modulus, hardness and abrasion resistance. In addition to mechanical properties, other physical properties are favorably improved, including lower thermal conductivity, fire resistance, and improved oxygen permeability.
摘要:
A method of using metallized and nonmetallized nanostructured chemicals as surface and volume modification agents within polymers and on the surfaces of nano and macroscopic particulates and fillers. Because of their 0.5 nm-3.0 nm size, nanostructured chemicals can be utilized to greatly increase surface area, improve compatibility, and promote lubricity between surfaces at a length scale not previously attainable.
摘要:
Method is provided for controlling the stereo chemistry of functionalities or X groups to exo or endo positions on a polyhedral oligomeric silsesquioxane (POSS) compound by adding certain reagents to said X groups to change one or more positions thereof to endo or exo. Also provided are the POSS species formed by the above inventive method. Method is also provided for inserting a ring substituent into a POSS compound. Also provided are the POSS species formed by such inventive method.
摘要:
Method is provided for reacting silsesquioxane resins or polyhedral oligomeric silsesquioxanes (POSS) bearing one or more olefinic groups with strong acids to cleave one or more olefin bonds of the olefinic groups to form POSS species of monomers or polymers having one or more functionalities suitable for reaction with a wide range of polymeric systems, to thus form new POSS derived compounds. Also provided are the new compounds so formed.
摘要:
A method of using metallized and nonmetallized nanostructured chemicals as surface and volume modification agents within polymers and on the surfaces of nano and macroscopic particulates and fillers. Because of their 0.5 nm-3.0 nm size, nanostructured chemicals can be utilized to greatly increase surface area, improve compatibility, and promote lubricity between surfaces at a length scale not previously attainable.