Plastic / Polymer Testing and Analysis

Thermogravimetry or TGA:

  • Weight of each component of a copolymer
  • Confirmation of a particular plastic based on the decomposition or oxidation temperature
  • Weight of volatile components or adsorbed liquids such as water, organic solvents, fuel, or oils
  • Weight of fill materials such as carbon black, calcium carbonate, aluminum trihydrate, silica, talc, zinc oxide, titanium dioxide, bentonite, kaolin clay, strontium oxide, mica, glass microspheres, antimicrobial copper or silver particles or thin films, and metal oxide powders used as fire retardants, UV blockers, colorants, thermal insulation, electrical conductivity promoters, and x-ray absorbers
  • Weight of reinforcing materials such as carbon fiber, fiberglass, or silicon carbide
  • Prepares fill material for identification by XPS below by decomposing or burning off the polymer matrix

Thermomechanical Analysis or TMA or Dilatometry:

  • Thermal expansion properties, coefficient of thermal expansion (CTE)
  • Softening temperature and glass transition temperature, Tg
  • Relative degree of polymer crystallinity
  • Shrinkage due to adsorbed liquids such as water, fuel, or oils being volatilized
  • Shrinkage upon cure
  • Swelling characteristics due to adsorption of a liquid
  • Identification of the number of organic layers or materials in a coating such as wax coatings on transfer paper
  • Static creep

Differential Scanning Calorimetry or DSC:

  • Glass transition temperature
  • Degree of cure or cross-linking, optimization of cure time, check on ratio mixture of 2-part adhesives
  • Endothermal or exothermal phase changes or reactions, including melting temperature and measurement of the heat of fusion
  • Polymorphism
  • Measure the heat and temperature of crystallization
  • Heat of vaporization of water or other volatiles
  • Detection of impurities or secondary components by distinct melting temperatures or by thermally stimulated reaction with the primary ingredient
  • Measure the latent heat of melting of a component polymer in a material with multiple polymers in it to determine the percentage of the melting polymer, such as of nylon 6 in a fabric with Spandex
  • Oxidation temperature and energies
  • Detect isomorphic organic components by reactions at or above the melting temperature
  • Specific heat measurement
  • Producing a phase diagram for a physical system

FTIR or Infrared Spectroscopy:

  • Identification of bonding groups
  • Identify polymer or plastic
  • Use specular reflectance angle-dependent results to distinguish surface from near-surface species, as for multiple polymer layers
  • Identify surface organic contaminants
  • Identify pharmaceutical materials, including pill coatings and timed-release agents
  • Identify organic contaminants
  • Adhesive bond failure investigation

X-ray Photoelectron Spectroscopy or XPS or ESCA:

  • Quantitative elemental and functional group chemical analysis of polymers
  • Measurement of surface contamination
  • Quantitative elemental & functional group analysis of surface treatments to affect such properties as coefficient of friction, dissipation of static charge, printability, changes due to sterilization or cleaning processes, bondability, reactivity, and degradation
  • Identification of solid residue components due to fill materials after TGA burn-off of plastic
  • Surface chemistry of fill materials prior to addition to polymer, which may affect wetting and aggolmeration of particles
  • Detection of components that segregate to the plastic surface, such as plasticizers, organic fire retardants, and fill particles with poor surface wetting properties
  • Identify layer or interface of delamination or peeling and whether a contaminant is present there
  • Investigate adhesive bonding failures due to surface segregation of plasticizer, inorganic fill particles such as talc, or migration of sodium from silica particle surfaces; or due to mold release agent or other contaminant; or due to stress in coating caused by internal layer contamination; or due to adhesive or primer degradation
  • Polymer sealing problems
  • Polyethylene fiber surface analysis with coating and after stripping the coating  This is also an example of a report.

Profilometry or White Light Interference Microscopy:

  • Measure surface roughness
  • 3-dimensional surface topography mapping

SEM and Microscopic Failure Analysis:

  • Identify type of failure
  • Examine surface roughness, microcracking, porosity, and pin-holes
  • Identify location of crack initiation in failure
  • Determine morphology of reinforcing materials
  • Identify the layer or interface at which delamination or peeling occurs
  • Document interfacial segregation of fill particles and any agglomeration, which is evidence of a high particle/resin interfacial energy

Analysis of Multilayered Plastic Films:

  • Analysis of outer layers with FTIR and XPS
  • Solvent rub may allow interior layers to be exposed and analyzed with FTIR and XPS
  • Use fine abrasive to expose interior layers for analysis
  • Analyze entire film or thinned film with DSC to gain further identifying information on the interior polymer layers

ASTM Test Methods:

  • ASTM D570 – Standard Test Method for Water Absorption of Plastics
  • ASTM D572 – Standard Test Method for Rubber-Deterioration by Heat and Oxygen
  • ASTM D2584 – Standard Test Method for Ignition Loss of Cured Reinforced Plastics
  • ASTM E228 – Standard Test Method for Linear Thermal Expansion of Solid Materials with a Vitreous Silica Dilatometer
  • ASTM E928 – Standard Test Method for Determination of Purity by DSC
  • ASTM E1269 – Standard Test Method for Determining Specific Heat Capacity by DSC
  • ASTM E1356 – Standard Test Method for Glass Transition Temperatures by DSC
  • ASTM E2160 – Standard Test Method for Heat of Thermally Reactive Materials by Differential Scanning Calorimetry
  • ASTM E793 – Standard Test Method for Enthalpies of Fusion and Crystallization by Differential Scanning Calorimetry
  • ASTM E831 – Standard Test Method for Linear Thermal Expansion of Solid Materials by Thermomechanical Analysis
  • ASTM E1131 – Standard Test Method for Compositional Analysis by Thermogravimetry
  • ASTM E1545 – Standard Test Method for Assignment of the Glass Transition Temperature by Thermomechanical Analysis
  • ASTM E2008 – Standard Test Method for Volatility Rate by Thermogravimetry

See other ASTM Standard Test Methods for Plastics and Rubbers on our Test Methods page under the Plastics and Rubbers Categories.