Design of Aromatic Thermosetting Copolyester Compositions and Blends for Thin Film Applications
Xu, Kun
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/82719
Description
Title
Design of Aromatic Thermosetting Copolyester Compositions and Blends for Thin Film Applications
Author(s)
Xu, Kun
Issue Date
2002
Doctoral Committee Chair(s)
Economy, James
Department of Study
Materials Science and Engineering
Discipline
Materials Science and Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Engineering, Mechanical
Language
eng
Abstract
This thesis is devoted to the development, synthesis, properties, and applications of aromatic thermosetting copolyester (ATSP) and multicomponent systems of ATSP and polyimide thin films. Originally, ATSP was developed as a high performance structural polymer. One drawback to this system is the inability to prepare uniform thin films from NMP solutions of ATSP oligomers. To be used in thin film applications, the synthesis and curing of ATSP oligomers are optimized, permitting formation of uniform thin films. The optimized ATSP thin films display sharp improvements in their dielectric properties. Two thin film applications have been investigated. One, because foaming can reduce the dielectric constant, the possibility of foaming ATSP using the reaction byproduct during curing is an attractive concept in developing ATSP as a low k dielectric. To this end, the nature of pore formation was investigated and avenues of research for producing foamed ATSP with controlled pore morphology are suggested. Second, the application of ATSP as a sub-micrometer adhesive in solid-state integration of microelectronic devices is explored. In this study we characterize the adhesion mechanism between ATSP and polyimide using DSIMS and demonstrate the effectiveness of this solid state integration technique in a mesoscopic device. In addition, two approaches have been taken to design multi-component systems of ATSP and polyimide thin films with the aim of obtaining optimized properties from the combination of both polymers. In the first approach, thin film blends of ATSP and polyimide have been prepared. Emphasis is placed on the study of the phase separation and surface segregation behavior using a combination of techniques including DSIMS, 3He NRA and AFM. A remarkable yet stable five-layered lamellar structure has been observed in a thin film blend of ATSP and polyimide, representing the first observation of surface directed spinodal decomposition in a thin film blend of high performance polymers. To our knowledge, all other studies on this phenomenon have been limited to model polymers. In the second approach, a hyperbranched copoly(imide-ester) (HBPIE) has been synthesized and characterized. Most interestingly, the HBPIE has a surface area of 83 m2/g, due to their intrinsic and stable microporosity (pore size 12.7 A). Further, HBPIE thin films displays an intermediate dielectric constant (3.6) and high dielectric breakdown strength (330 V/mum). HBPIE thin films could find potential application as reverse osmosis membranes or dielectric thin films in capacitors.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
