Abstract: A thin micro-multilayer electrical insulator having a plurality of layers of polymeric materials is high performance and lightweight. The insulator provides a structured material with improved dielectric strength and partial corona discharge resistance that can be used in high voltage and high temperature applications. The durable insulator is well suited for use in insulating high voltage aircraft wiring and power transmission composites in hybrid and all electric airplanes. The insulator can have multiple layers of different polymeric materials such as fluorine-containing polymers and polyimides.
Type:
Grant
Filed:
April 11, 2019
Date of Patent:
January 28, 2020
Assignees:
OHIO AEROSPACE INSTITUTE, U.S. GOVERNMENT AS REPRESENTED BY THE ADMINISTRATOR OF THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
Abstract: Porous cross-linked partially aliphatic polyimide networks are provided. The polyimide networks comprise a polyamic acid oligomer that (i) comprises a repeating unit of a dianhydride and a diamine and terminal functional groups, (ii) has an average degree of polymerization of 10 to 70, (iii) has been cross-linked via a cross-linking agent, comprising three or more cross-linking groups, at a balanced stoichiometry of the cross-linking groups to the terminal functional groups, and (iv) has been chemically imidized to yield the porous cross-linked polyimide network. The polyimide networks are partially aliphatic based on (a) the diamine comprising a first diamine and a second diamine, wherein the first diamine comprises a linear aliphatic backbone chain, and the second diamine does not, and/or (b) the dianhydride comprising a first dianhydride and a second dianhydride, wherein the first dianhydride comprises a linear aliphatic backbone chain, and the second dianhydride does not.
Type:
Grant
Filed:
October 11, 2017
Date of Patent:
October 1, 2019
Assignees:
OHIO AEROSPACE INSTITUTE, U.S. GOVERNMENT AS REPRESENTED BY THE ADMINISTRATOR OF THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
Inventors:
Mary Ann B. Meador, Baochau N. Nguyen, Haiquan Guo
Abstract: Structurally stable and mechanically strong ceramic oxide aerogels are provided. The aerogels are cross-linked via organic polymer chains that are attached to and extend from surface-bound functional groups provided or present over the internal surfaces of a mesoporous ceramic oxide particle network via appropriate chemical reactions. The functional groups can be hydroxyl groups, which are native to ceramic oxides, or they can be non-hydroxyl functional groups that can be decorated over the internal surfaces of the ceramic oxide network. Methods of preparing such mechanically strong ceramic oxide aerogels also are provided.
Type:
Application
Filed:
February 8, 2010
Publication date:
July 15, 2010
Applicants:
Ohio Aerospace Institute, U.S. Government, represented by the Administrator of the National Aeronautics & Space Administration
Inventors:
Nicholas Leventis, Mary Ann B. Meador, James C. Johnston, Eve F. Fabrizio, Ulvi F. Ilhan