Characterization, Analysis, And Testing Flashcards
A technique used to determine the molecular properties, structure, and behavior of polymers.
Polymerization Characterization
Involves a count of the number of molecules of each species, NiMi, summed over i, divided by the total number of molecules.
Number-Average Molecular Weight
Commonly used as a simple measure of the polydispersity of the polymer sample.
Polydispersity Index (PDI)
Enumeration.
Determination of Molecular Weight.
- End-group Analysis
- Measurement of Colligative Properties
- Light Scattering
- Ultracentrifugation
- Dilute Solution Viscometry
- Gel Permeation Chromatography (GPC)
A chemical method use for calculating the number-average molecular weight of polymer samples whose molecules contain reactive functional groups at one end or both ends of the molecule.
End-group Analysis
Properties of solutions that depend on the number of molecules present and not on the kind of molecules
Colligative Properties
In applying this method, the boiling point of a solution of known concentration is compared to that of the solvent at the same pressure.
Ebulliometry (Boiling Point Elevation)
Calculation of the freezing-point depression of the solvent and hence the molecular weight of the solute by this method proceeds exactly the same way as for the boiling point elevation .
Cryoscopy (Freezing Point Depression)
A technique for the determination of molecular masses of polymers by means of osmosis. The phenomenon of osmosis describes the attempt of solvent molecules to go through a semipermeable membrane into a solution.
Membrane Osmometry
A technique that measures the intensity of the scattered light to obtain the average molecular weight Mw of a macromolecule like a polymer or a protein in solution.
Static Light Scattering
The measure of the opposing force of material to flow.
Viscometry
The most common type of viscometer that is used for the determination of viscosity of polymer solution.
Ubbeholde Viscometer
A process for the separation of polymer molecules according to their size.
Gel Permeation Chromatography
Used to purify and characterize low molecular weight polymers.
Ultracentrifugation
Proved to be a rapid and precise method of molecular weight determination, often requiring as little as a half hour per sample
Gel Permeation Chromatography
A microscale property that is largely dictated by the amorphous or crystalline portions of the polymer chains and their influence on each other.
Polymer Morphology
The polymer is allowed to react to form low molecular weight fragments that are condensed at liquid-air temperature.
Mass Spectrometry
An ionization technique that uses a laser energy-absorbing matrix to create ions from large molecules with minimal fragmentation.
Matrix-Assisted Laser Desorption/Ionization (MALDI)
A method of separation in which gaseous or vaporized components are distributed between a moving gas phase and fixed liquid phase or solid adsorbent.
Gas Chromatography
Analysis of infrared light interacting with a molecule. This can be analyzed in three ways by measuring absorption, emission and reflection.
Infrared Spectroscopy.
A non-destructive analytical technique that measures the absorption or transmission of infrared radiation by a sample as a function of frequency or wavelength.
Fourier Transform Infrared Spectroscopy (FTIR)
A powerful analytical technique used to study the molecular structure, dynamics, and composition of organic and inorganic compounds.
Nuclear Magnetic Resonance Spectroscopy (NMR)
It works by measuring the presence of paramagnetic ions or molecules with unpaired electrons, and by observing the resonant absorption of microwaves within a static magnetic field.
Electron Paramagnetic Resonance Spectroscopy
It is used to study the absorption of ultraviolet and visible light by polymer molecules.
Ultraviolet-Visible Spectroscopy (UV-Vis)
An analytical technique used to study molecular vibrations in materials by measuring the scattering of light when it interacts with a sample.
Raman Spectroscopy
A non-destructive technique that provides detailed information about the crystallographic structure, chemical composition, and physical properties of a material.
X-ray Diffraction Analysis
A category of microscopes that uses visible light to magnify and image small samples.
Light Microscope
A technique used to observe the orientation of molecules in a sample under a microscope.
Polarized-light Microscopy
A type of microscopy that uses interference patterns produced by the incoherent light scattered by specimens to create an image.
Phase-contrast Microscopy
A microscope that uses a beam of electrons as a source of illumination.
Electron Microscopy
A type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons.
Scanning Electron Microscope (SEM)
A type of electron microscope that transmits electrons through a thin sample, resulting in an image of the sample’s interior structure at the atomic level.
Transmission Electron Microscopy (TEM)
A thermoanalytical technique in which the difference in the amount of heat required to increase the temperature of a sample and reference is measured as a function of temperature.
Differential Scanning Calorimetry
The material under study and an inert reference are made to undergo identical thermal cycles while recording any temperature difference between sample and reference.
Differential Thermal Analysis
A sensitive balance is used to follow the weight change of the sample as a function of temperature.
Thermogravimetric Analysis
Measures the mechanical response of a polymer system as the temperature is changed.
Thermochemical Analysis
This is usually done by measuring continuously the force developed as the sample is elongated at constant rate of extension.
Stress-Strain Properties in Tension
The maximum stress that a material can withstand while being stretched or pulled before breaking.
Tensile Strength
A material property and is the stress corresponding to the yield at which the material begins to deform plastically.
Yield Strength
A mechanical property of solid materials that measures the tensile or compressive stiffness when the force is applied lengthwise.
Young Modulus
A measure of the stress or force that is applied in a direction parallel to the surface of a material
Shear Stress
The force per unit area perpendicular to the plane of shearing force.
Shear Stress
Refers to the bending or storage of stress or strain in a material
Flexure
A mechanical phenomenon that occurs when force is applied to a flexible material.
Flexure
The force that is responsible for the deformation of the material such that the volume of the material reduces.
Compressive Stress
Is the stress experienced by a material which leads to a smaller volume.
Compressive Stress
True or False.
High compressive stress leads to failure of the material due to tension.
True
The twisting of an object due to an applied torque.
Torsion
When subjected to cyclic mechanical stresses, most materials fail at a stress considerably lower than that required to cause rupture in a single stress cycle.
Fatigue
Measures the ability of a material to resist deformation in response to a sudden load.
Impact Test
Occurs if the material behaves elastically up to the point of failure.
Brittle Rupture
Occurs when the specimen is permanently distorted near the point of failure.
Ductile Rupture
The temperature at the onset of brittleness, is usually determined by subjecting a specimen to impact in a standardized but empirical way.
Brittle Point
From the travel of the pendulum after breaking the specimen can be calculated the energy required to cause the break.
Impact Strength
True or False.
When plastics are used as films, particularly in packaging applications, their resistance to tearing is an important property.
True
A composite property combining concepts of resistance to penetration, scratching, marring, and so on.
Hardness
Usually takes the form of a scratch test.
Abrasion Resistance
Defined as the temperature at which the resins flow under a given load on heating.
Softening Temperature
A polymer sample becomes molten and leaves a trail when moved across a hot metal surface with moderate pressure.
Polymer Melt or Stick Temperature Test
A polymer specimen fails in tension under its own weight.
Zero-strength Temperature Test
The burning rate of a specified sample.
Flammability
The ratio of the intensities of light passing through and light incident on the specimen.
Transmittance
The ratio of the intensities of the reflected and the incident light.
Reflectance
One that transmit part and reflects part of the light incident on it.
Translucent
The subjective sensation in the brain resulting from the perception of those aspects of the appearance of objects that result from the spectral composition of the light reaching the eye.
Color
The geometrically selective reflectance of a surface responsible for its shiny or lustrous appearance.
Gloss
For transparent materials, it is the percentage of transmitted light that in passing through the specimen deviates from the incident beam by forward.
Haze
The state permitting perception of objects through or beyond the specimen.
Transparency
Refers to their degree of clarity or opacity, or how much they allow light to pass through them.
Transparency of Polymers
Refers to the ability of a polymer material to resist the flow of electrical current.
Resistivity
A measure of a material’s ability to store electric charge.
Dielectric Constant
Measure of its ability to sustain high-voltage differences without current breakdown.
Dielectric Strength
The ability of the plastic material to resist the action of a high voltage electrical arc and resist the formation of a conducting path along its surface under a given time.
Arc Resistance
The absorption of water.
Swelling
The specimen fails by breaking when exposed to mechanical stress in the presence of an organic liquid of an aqueous solution of a soap or other wetting agent.
Environmental Stress Cracking
A specimen fails by the development of a multitude of very small cracks in the presence of an organic liquid or its vapor, with or without the presence of mechanical stress.
Crazing
The product of the solubility of the gas or vapor in the polymer and its diffusion coefficient.
Permeability of a Polymer to Gas or Vapor
Directly measured as the rate of transfer of vapor through unit thickness of the polymer in film form, per unit area and the pressure difference across the film.
Permeability
The ability of a polymer material to allow certain gases or vapors to pass through it.
Vapor Permeability
The process of degradation of polymers or large molecules due to exposure to external factors such as sunlight, temperature, and chemicals.
Weathering
