Summary Record of the Workshop on Polymer Materials Research: August 30-31, 1999, Woods Hole, Massachusetts (2000)

The workshop participants were arbitrarily split into four discussion groups to identify the research areas most likely to lead to the development of improved polymers for Air Force applications. Summaries of the discussions follow.

Group 1 identified four general areas of research:

• cure (processing) approaches for rigidized space and aerospace structures

• multifunctional optoelectronic polymers (active and passive)

• “polymers for life”

• “designer” composite concepts

Group participants identified the following research opportunities for cure approaches for rigidized space and aerospace structures:

• anaerobic mechanisms to increase stiffness

• novel addition mechanisms

• ambient cures

• complex three-dimensional or ladder structures

• environmental aids to processing (e.g., space aids)

• new solvents

Group participants identified the following research opportunities related to multifunctional optoelectronic polymers (active and passive):

• synthetic metallic polymers

• synthetic superconducting polymers

• tunable properties on demand

• conductive elastomers

• polymers for optical computing

• magnetic polymers

Group participants identified the following research opportunities related to “polymers for life.”:

• polymers for space-based extreme environments (e.g., radiation, thermal cycling, atomic oxygen, and vacuum)

• methods for life prediction and characterization (e.g., suitable test facilities, predictive modeling capability)

• polymers that resist fuel-generated hazards (e.g., liquid oxygen)

• long-life coatings

• self-healing structures

Group participants identified the following research opportunities related to designer composite concepts:

• hierarchical structure control

• integration of processing and materials synthesis (i.e., “growing” of structure), at both the molecular and nanometer scales

• self-assembly

• biomimetic structures

• in situ design of polymer morphology

• controlled distributions (e.g., molecular weights, functions, time response, fields)

Group 2 identified three primary areas of research:

• polymer microfabrication, self-assembly, and thin films

• smart polymers

• information management and display

For each area the group then identified potential applications, the current state of development, research objectives, barriers to development, and potential non-DOD applications.

On the first topic, microfabrication, self-assembly, and thin films, participants made the following observations:

• Potential applications include nanosatellites, polymer MEMS, self-fabrication of structures or components, polymer-based optics, and affordable micro air vehicles.

• The state of development is promising for applications by 2020.

• Research objectives include capability of producing larger area and larger volume (compared to silicon) components at lower cost.

• The main barrier to development is the theoretical basis for the thermodynamics of small, nonequilibrium systems.

• Non-DOD applications include : commercial satellites, health care, environmental uses, desalination, commercial fuel cells, and barrier materials.

On the subject of smart polymers, participants made the following observations:

• Potential applications include active stealth, self-healing and diagnostic systems, laser protection, and sensors (e.g., for nuclear-biological-chemical agents).

• The state of development ranges from well known (e.g., piezoelectrics) to new (e.g., photomagnetic).

• Research objectives include (1) general improvements in the performance and optimization of systems and (2) the combination of sensing and response in one material.

• The major barrier to development is the limited range of response of smart polymers.

• Non-DOD applications are numerous, ranging from medical devices to industrial processing.

About the third topic, information management and display, participants made the following observations:

• Potential applications include portable displays, real-time holography (3Ddisplay), large band width communication, and DNA encryption.

• The state of development varies for different technologies; display technology has been demonstrated, but the scale and range must be increased; communications technology is still emerging.

• Research objectives include higher speeds, broader bandwidth, more rugged devices, and lower power consumption.

• Barriers to development include limited availability of materials, inadequate control of purity and morphology, and the lack of security and encryption technologies.

• Non-DOD applications are mainly in commercial communications.

Finally, participants suggested that the AFRL promote research and education by:

• providing remote testing facilities

• maintaining a centralized characterization capability

• facilitating communications in the research community

• providing mechanisms for research collaborations

• providing education and training of young scientists

Group 3 began with a brainstorming discussion of the technologies most likely to lead to the development of improved polymers for Air Force applications. The group identified the following technologies:

• ring-opening polymers that do not shrink when cured

• effect of purity on electrooptic polymers

• tailorable multifunctional polymers

• magnetic polymers for low observables

• superconductive polymers

• organic transistors

• polymer MEMS

• polymers for micro uninhabited air vehicles (UAVs)/disposable aircraft/smart bombs

• precision tethers for use in space

• composite field repair for aging aircraft

• flexible polymer photovoltaics

• incapacitating technologies

• interface technology

• elastomers suitable for use at −65°F to +500°F

• characterization techniques for molecular homogeneity

• low-cost nanofabrication

• creative degradation (very long-term durable polymers)

• photorefractive polymers

• organic-inorganic polymers for high-temperature applications

The participants then suggested grouping of these technologies and determined rough priorities. The following technologies were considered to be the most promising:

• tailorable, better-defined polymer structures (with purity in chemical composition, architectural structure, and bulk/surface morphological features)

• controlled shrinkage polymers, including ring-opening polymers that do not shrink during cure

• functional polymers for space-based applications, including controllable large structures that have creative degradation features

• polymers that are resistant to space environments (durability in space)

Group 3 agreed that a significant barrier to the development of all of these technologies was the lack of rapid communication and feedback from the user community.

The group participants identified the following long-term research objectives:

• defining the properties of structures for use in space

• assessing the effects of purity

• supporting basic research on interfaces, durability, rapid cure and maintainability, and cryogenic properties

Many participants felt that an interdisciplinary approach in research would be most productive.

Group 4 participants identified five general areas for research:

• nanostructural organization

• polymers in extreme environments

• increasing electron transport

• magnetic polymers

• polymers for electronic, optical, or optoelectronic applications

The following research opportunities related to nanostructural organization were identified:

• the development of characterization methods for nanostructures

• the development of fabrication methods

• increased understanding of metallized polymers, including the development of fabrication methods, the characterization of interactions, the identification and characterization of degradation mechanisms, and the development of magnetic or electromagnetic applications

• increased understanding and utilization of modulated surface interactions

• identification of applications of nanostructures for sensing surfaces

• the development of methods for using nanostructural organization for creating tailored surfaces (e.g., smart surfaces)

• the use of nanostructural organization in MEMS

• the use of nanostructural organization for dynamic polymer actuation, photoactivation, and transport systems

• the use of nanostructures in biomimetic systems

The following research opportunities on the use of polymers in extreme environments were identified:

• high glass-transition temperature materials

• nonbrittle high-temperature polymers

• processible materials (e.g., hybrid systems)

• polymer systems optimized for use in space environments

Some participants suggested that the Air Force sponsor a workshop related to the development of, and applications for, polymers with increased electron transport. Participants identified the following potential for polymers with increased electron transport:

• photovoltaics

• lasers

• transistors

• materials with enhanced thermal conductivity

• optically reconfigurable radar

• displays

The following research opportunities on magnetic polymers were identified:

• enhanced magnetic performance through nanostructural control

• improved theoretical understanding of magnetic polymers

• identification and characterization of environmental drivers (e.g., aircraft fluids, corrosive environments)

Finally, participants identified the following research opportunities related to polymers for electronic, optical, or optoelectronic applications:

• polymer power systems (e.g., photovoltaics, fuel cells, batteries)

• holographic polymers

• light-emitting polymers

• two-photon circuit writing

• active or passive integrated systems

• broadband, nonlinear absorption

• infrared detection at ambient conditions