The document discusses the measurement and importance of various response functions in composite structures made of polypyrrole (PPy) and polydimethylsiloxane (PDMS). It describes the dielectric response, viscoelastic response, and Young's modulus of these composites. The dielectric constant of PPy-PDMS composites is significantly higher than pure PDMS due to interfacial polarization. The viscoelastic properties and creep depth increase with electrolyte concentration, influenced by dopant ions. Elastic modulus increases with higher PPy nanowire concentration, providing enhanced electrical and mechanical properties while maintaining mechanical compliance.

1. General survey of important
response functions measured
Polarization of composite structure made of Ppy and
PDMS.
Visco-elasticity of structure.
Young modulus.(Mechanical response)
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2. General survey of important response
functions measured (contd.)
Function Why is this function important?
Dielectric Response high dielectric constant may play an important
role in various applications such as dielectric
resonators, patch antennas, dielectric lenses
and dielectric elastomer actuators
Viscoelastic response various micro-structures (posts, grooves,
channels, etc) can be potentially applied to study
the cellular behaviour and its interaction with
extra cellular environment in morphological,
mechanical and electrical approaches
Young modulus Of particular interest because their
electromechanical transduction is similar to the
natural muscle-great potential in the biomimetic
robots
Tunable electrical and mechanical responses of PDMS and polypyrrole nanowire
composites-Ping Du, Xi Lin and Xin Zhang-Journal of Physics D: Applied Physics,2013
CH5190: Inroduction to Macromolecules

3. Example 1: Dielectric response
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function
• Dielectric constants of have similar
frequency-dependent relaxation
behavior, decreasing monotonically as
the frequency f increases.
• High dielectric constant of the PPy at
lower frequency is mainly due to the
interfacial polarization.

4. Example 2: Viscoelastic response
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function
 solvated counter ions,
increased the effective free
volumes in the conducting
polymer phase, and therefore
further enhanced the viscous
behaviour of the PDMS–PPy
composites.
 creep depth increased with the
support electrolyte conc
entration, which suggested that
the dopant ions were dominant
in the viscoelastic response of
conducting polymers.

5. Example 3:Young’s Modulus
 Elastic moduli of the
composites increase
monotonically with the
nanowire concentration.
 Moderate enhancement in the
elastic moduli-beneficial for the
elastomer applications which
require compliant structures.
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6. CH5190: Inroduction to Macromolecules
Summary
• Dielectric constant of 10 vol% PDMS composite achieved
an 85-fold augment as compared with the pristine PDMS.
• Tunable multifunctionality of PPy composites that possess
enhanced electrical and viscoelastic properties within
mechanically compliant structures enables the design of
more advanced sensing and actuating applications.
Tunable electrical and mechanical responses of PDMS and polypyrrole nanowire
composites-Ping Du, Xi Lin and Xin Zhang-Journal of Physics D: Applied Physics,2013

7. A research statement about the
polymeric system of case study
Feasibility of Using Polypyrrole As A
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RAM(Radar
Absorbent Material) For Aircrafts

8. Research Motivation
• Polypyrrole–coated materials and other related
mixtures have been used for RAM.
• More study on conductivity and thermal stability for
this application is needed.
• Feasibility to produce low cost products.
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9. CH5190: Inroduction to Macromolecules
Work plan
• To check shielding effect of conducting fabric against
electromagnetic radiation
• Finding the cause behind conducting nature of
Polypyrrole.
• Thermal stability of Polypyrrole in airborne situation.
• Feasibility for ground level structures made with such
RAM.

10. Expected outcome
• Low budget radar absorbent material preparation for
aircrafts and static radar structures.
CH5190: Inroduction to Macromolecules