Leslie Fishbein

1
Rheological Capabilities at TACOM-ARDEC

• Presented by
• Leslie Fishbein
• Armament Systems Process Division
• WECAC

2
Purpose

• Provide an overview of efforts to establish a
  state-of-the-art energetic materials
  characterization laboratory at TACOM-ARDEC

3
Outline

• Mission
• Equipment Capabilities
• Future Work
• Summary

4
The TACOM-ARDEC Mission

• The Rheology Laboratory will enhance
  TACOM-ARDECs role as a leading developer of new
  energetic compositions and processes
• FCS propellants in support of the Multi-role
  Armament and Ammunition System (MRAAS)
• State-of-the-art processing of energetic
  materials at the Building 1403 Twin-Screw
  Mixer/Extruder
• Process modeling and simulation
• Support of items in production (e.g., M30A1,
  JA-2, AA-2, PAP-7993, M14, Ball Powders)
• Opportunities to team with Industry and Academia
• Stevens Institute of Technology (SIT)
• Polymer Processing Institute, New Jersey
  Institute of Technology (NJIT)
• ATK/Radford AAP
• GENCORP Aerojet
• ATK/Thiokol Propulsion

5
The Rheological Laboratory

• Consolidate rheological capabilities under one
  roof
• Remotely operated systems
• User friendly software for data acquisition and
  analysis
• Support TACOM-ARDEC material characterizations
• Energetic materials (Propellants, Explosives,
  Pyrotechnics)
• Precursor Materials (e.g., ETPEs, binders)
• Plastics
• Epoxies
• Composites
• Resins
• Support process modeling and simulation efforts
• Twin-Screw Mixer/Extruder
• Shear Roll Mill
• Cryogenic Polymerization Reactor

6
Capillary Rheometer

• Similar to laboratory-scale extruder that is
  highly instrumented and accurately controlled
• Relate changes in processing conditions
  (pressure, temperature) of extrusion to product
  properties (mechanical, ballistic)
• Characterize the rheological/flow properties of
  energetic materials under different conditions
  (temperature, composition)
• Obtain a constitutive equation for the energetic
  materials for process analysis and simulation
  using RheoPlotter software

• Instron Load Frame Model 5581 and
• Shear Tool Capillary Adapter Assembly

7
Capillary Rheometer

• To determine the rheological properties as a
  function of shear rate, temperature, pressure,
  and molecular weight, which is crucial to the
  design and control of process operation

Apply Different Speeds (S) at controlled
Temperature
Obtain Forces (Resistance to Flow)
Data Analysis
Viscosity F (shear rate, temperature)
Relate To
Flow in Processing Equipment
Die Forming
8
Rheometric Scientific Dynamic Analyzer- RDA III
Rotational Rheometer

• Study the dynamic mechanical properties of the
  energetic materials (G?, G??, tan ?)
• Study the complex viscosity (?) and viscoelastic
  behavior
• Investigate the molecular structure and
  interaction/compatibility between the ingredients
  of the energetic materials
• Study the reaction kinetics of reactive system

9
Rotational Rheometer

• Measures viscosity, elasticity and shear modulus
• Can perform controlled strain, stress and strain
  rate experiments
• Includes range of test fixtures
• Parallel plate
• Torsion fixtures
• Allows for characterization from
• Suspensions, emulsions,
• Polymer melts, elastomers
• Solids

Apply Strain AA0sin?t where A0 small amplitude
Measure Torque, Normal Force
Obtain Normal Force, TorqueTorque T? sin ?t
T?? cos ?t
Data Analysis
Elastic Properties
Viscous Properties
Apply Strain AA0sin?t
Relate To
Structure of the Mixture (MW, concentration,
degree of mixing, compatibility, crosslinking)
10
Torque Rheometer

• The Poly Lab 300p enables production of small
  batches with simultaneous recording of torque and
  time while mixing material
• High torque capability
• Oil heated and cooled chamber and plates
• Rotors for different shear ranges
• Roller blades (viscous properties for
  thermoplastics thermosets)
• Cam blades (thermoplasts elastomers in medium
  shearing range)
• Banbury blades (natural and synthetic rubber)
• Sigma blades (low shear ranges most suitable
  f/energetic materials)
• Teflon bushings to test chemically aggressive
  media
• Special tools to clean the mixer parts
• Pneumatic ram
• Poly View data evaluation i.e.
• Routine evaluation --Rheograms (torque vs. time)
• Multi curve Analysis

11
Torque Rheometer

• The torque rheometer is capable of the measuring
  the following
• Dynamic viscosity depending on shear load
• Melt behavior in the extruder
• The influence of additives
• Temperature and shear load behavior
• TACOM-ARDEC will mainly be using Rheometer
  for its mixing capabilities

Thermo Haake Poly-Lab 300p System
12
Internal Mixer Torque Rheometer
13
Planned Work Loading FY 03

• Army
• Characterization of JA-2 and AA-2 propellant
  produced on a Shear Roll Mill (ManTech)
• Supports modeling activity w/SIT
• Leveraged with implementation of SRM technology
  in support of the manufacture of solventless
  propellants at Radford AAP
• Characterization of ETPEs (ManTech)
• Supports TACOM-ARDEC modeling activity and ETPE
  process optimization
• Begin developing of rheological data base for
  energetic materials consider for TSE processing
  (ManTech)
• Propellants (e.g., M39 / M43 LOVA)
• Explosives (e.g., PAX-2A IM)
• Pyrotechnics (e.g, M206, MJU-7A/B, MJU-53/B)
• 155-mm M485 Illumination Round
• Characterization of replacement material for
  liquid polysulfide

14
Planned Work Loading Initiatives

• Potential (3rd party)
• ATK / Radford AAP (gun propellants)
• Full-time PhD Rheologist -- no laboratory
  capability
• ATK / Thiokol Propulsion (rocket and gun
  propellants)
• GENCORP Aerojet (CRADA tasking)
• BAE Systems / Holston AAP (explosives)
• SIT (in support of process modeling)
• PPI, NJIT (CRADA)
• Expand PPI commercial market place through use of
  Rheology Laboratory at TACOM-ARDEC

15
Summary

• Rheology Lab is in full operational status
• The characterization of Energetics is to be used
  to understand, simulate, design, and optimize the
  manufacturing processes
• CRADA has been signed with PPI/NJIT
• Future work is being discussed with SIT, ATK, and
  Aerojet
• Questions and Inquires to be addressed to
• Lilia Mastov
• TACOM-ARDEC
• [phone]
• lmastov_at_pica.army.mil