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Polymer engineering > CHARACTERIZATION, ANALYSIS, AND TESTING > Flashcards

CHARACTERIZATION, ANALYSIS, AND TESTING Flashcards

1
Q

Is a technique used to determine the
molecular properties, structure, and behavior of polymers.

A

Polymer characterization

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2
Q

If all species in a polymer sample have the same molecular weight (that
is, the polymer is _____)

A

monodisperse

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3
Q

The ratio Mw/Mn, called the _____, is commonly used as a simple measure of the polydispersity of the polymer sample.

A

polydispersity index (PDI)

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4
Q

Is 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.

A

end-group analysis

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5
Q

Properties of solutions that depend on the number of molecules present
and not on the kind of molecules are called ____.

A

colligative properties

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6
Q

In applying this method, the boiling point of a solution of known concentration is compared to that of the solvent at the same pressure.

A

Ebulliometry (Boiling Point Elevation)

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7
Q

Boiling point of the solution is ____ than the pure solvent. This phenomenon is used to determine the molecular weight of polymers.

A

higher

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8
Q

It works by analyzing the melting behavior of a substance as it is frozen. By measuring the time it takes for a specific substance to melt at a certain
temperature, its molecular weight can be calculated.

A

Cryoscopy (Freezing Point Depression)

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9
Q

Is 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.

A

Membrane osmometry

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10
Q

This method depends on the light, when the light is passing through polymer solution, it is measured by lose energy because of absorption, conversion to heat and scattering.

A

Light scattering method

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11
Q

Is 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. In a static light scattering measurement, a coherent laser beam is used to analyze a sample.

A

Static light scattering

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12
Q

Is defined as the measure of the opposing force of material to flow.

A

Viscosity

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13
Q

_____ equation gives the relationship between viscosity and average molecular weight:

A

Mark-Houwink

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14
Q

It is the most common type of
viscometer that is used for the
determination of viscosity of polymer
solution.

A

Ubbelohde viscometer

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15
Q

Is an extremely powerful method for determining the complete molecular weight distribution and average molecular weights. It is essentially a process for the separation of polymer molecules according to their size.

A

Gel permeation chromatography

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16
Q

GPC is also known as

A

Gel filtration
Gel exclusion chromatography
Size-exclusion chromatography (SEC), Molecular sieve chromatography

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17
Q

Are used to purify and characterize
low-molecular-weight polymers. Both Mw and Mz may be determined by subjecting dilute solutions of polymers in appropriate solvents to ultracentrifugal forces at high speeds.

A

Ultracentrifugation

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18
Q

The two techniques that are encountered most commonly are ____ and ____.

A

intrinsic viscosity; GPC

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19
Q

Is a microscale property that is largely dictated by the amorphous or crystalline portions of the polymer chains and their influence on each other.

A

Polymer morphology

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20
Q

The polymer is allowed to react to form low-molecular-weight fragments that are condensed at liquid-air temperature. They are then volatilized, ionized and separated according to mass and charge by the action of electric and magnetic fields

A

Mass spectrometry

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21
Q

In mass spectrometry, _____ is an ionization technique that uses a laser energy-absorbing matrix to create ions from large molecules with minimal fragmentation.

A

matrix-assisted laser desorption/ionization (MALDI)

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22
Q

Is a method of separation in which gaseous or vaporized components are distributed between a moving gas phase and fixed liquid phase or solid adsorbent.

A

Gas Chromatography

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23
Q

It is an analytical technique used to separate the chemical components of a sample mixture and then detect them to determine their presence or absence. It is also used to figure out how much is present in the sample

A

Gas Chromatography

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24
Q

It can provide detailed information about the molecular structure and composition of polymers, including their monomer sites, stereochemistry, and branching patterns.

A

Gas chromatography – mass spectrometry

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25
Q

It measures the vibrations of atoms, and based on this it is possible to determine the functional groups.

A

Infrared Spectroscopy

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26
Q

Is a non-destructive analytical technique that measures the absorption or transmission of infrared radiation by a sample as a function of
frequency or wavelength.

A

Fourier transform infrared spectroscopy (FTIR)

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27
Q

Is a powerful analytical technique used to study the molecular structure, dynamics, and composition of organic and inorganic compounds. It exploits the magnetic properties of certain atomic nuclei within a magnetic field to provide detailed information about the chemical environment of atoms in a molecule.

A

Nuclear Magnetic Resonance (NMR) spectroscopy

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28
Q

The major use of ____ spectroscopy lies in the detection of free radicals. It works by measuring the presence of molecules with unpaired electrons, and by observing the resonant absorption of microwaves within a static magnetic field.

A

Electron Paramagnetic Resonance Spectroscopy (EPR)

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29
Q

Is a valuable technique for analyzing
polymers, providing insights into their electronic structure, composition, and molecular interactions. When applied to polymers, it is used to study the absorption of ultraviolet and visible light by polymer molecules.

A

Ultraviolet–visible spectroscopy

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30
Q

Is an analytical technique used to study molecular vibrations in materials by measuring the scattering of light when it interacts with a sample. It provides information about molecular structure, chemical composition, and bonding within a sample based on the vibrational modes of its constituent molecules.

A

Raman Spectroscopy

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31
Q

Is a nondestructive technique that provides detailed information about the
crystallographic structure, chemical composition, and physical properties of a material.

A

X-Ray diffraction analysis

32
Q

Is a category of microscopes that uses visible light to magnify and image small samples.

A

Light microscope

33
Q

Is valuable for examining the texture of solid opaque polymers

A

Light Microscopy

34
Q

Is a technique used to observe the orientation of molecules in a sample under a microscope. It is often used with polymers to study their structure, as the orientation of the polymer chains can reveal information about their molecular organization.

A

Polarized light microscopy

35
Q

Is a type of microscopy that uses interference patterns produced by the incoherent light scattered by specimens to create an image.

A

Phase-contrast microscopy

36
Q

Is a microscope that uses a beam of electrons as a source of illumination. They use electron optics that are analogous to the glass lenses of an optical light microscope to control the electron beam.

A

electron microscope

37
Q

Is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that contain information about the surface topography and composition of the sample.

A

Scanning Electron Microscope (SEM)

38
Q

Is 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. It can reveal stunning detail at the atomic scale.

A

Transmission Electron Microscopy (TEM)

39
Q

Is 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

A

Differential scanning calorimetry

40
Q

A sensitive balance is used to follow the weight change of the sample as a function of temperature.

A

Thermogravimetric Analysis

41
Q

Measures the mechanical response of a polymer system as the temperature is changed.

A

Thermomechanical Analysis

42
Q

This is usually done by measuring continuously the force developed as the sample is elongated at constant rate of
extension.

A

Stress-Strain

43
Q

Is the maximum stress that a material can withstand while being stretched or pulled before breaking.

A

Tensile strength

44
Q

Is a material property and is the stress corresponding to the yield point at which the material begins to deform plastically.

A

Yield strength

45
Q

Is a mechanical property of solid materials that measures the tensile or compressive stiffness when the force is applied lengthwise.

A

Young’s modulus

46
Q

Is a measure of the stress or force that is applied in a direction parallel to the surface of a material. It is typically defined as the force per unit area perpendicular to the plane of shearing force.

A

Shear stress

47
Q

Refers to the bending or storage of stress or strain in a material. It is a mechanical phenomenon that occurs when force is applied to a flexible material.

A

Flexure

48
Q

Is the force that is responsible for the deformation of the material such that the volume of the material reduces.

A

Compressive stress

49
Q

Is the twisting of an object due to an applied torque.

A

Torsion

50
Q

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. This phenomenon is called ____.

A

Fatigue

51
Q

Are performed to measure the reduction in stiffness and strength of materials under repeated loading and to determine the total number of load cycles to failure.

A

Fatigue test

52
Q

Measure the ability of a material to resist deformation in response to a sudden load.

A

Impact tests

53
Q

Occurs if the material behaves elastically up to the point of failure.

A

Brittle rupture

54
Q

Occurs when the specimen is permanently distorted near the
point of failure.

A

Ductile rupture

55
Q

The ______, or temperature at the onset of brittleness, is usually determined by subjecting a specimen to impact in a standardized but empirical way.

A

brittle point

56
Q

_____ of plastics is commonly measured by tests in which a pendulum with a massive striking edge is allowed to hit the specimen.

A

Impact strength

57
Q

When plastics are used as films, particularly in packaging applications, their _____ is an important property.

A

resistance to tearing

58
Q

Is a composite property combining concepts of resistance to penetration, scratching, marring, and so on

A

Hardness

59
Q

Usually takes the form of a scratch test, in which the material is subjected to many scratches, usually from contact with an abrasive wheel or a stream of falling abrasive material.

A

Abrasion resistance

60
Q

Is defined as the temperature at which the resin flows under a given load on heating.

A

softening temperature

61
Q

Is usually tested as the burning rate of a specified sample.

A

flammability

62
Q

A major determinant of the appearance of a transparent. The ratio of the intensities of light passing through and light incident on the specimen.

A

transmittance

63
Q

Characterized the appearance of an opaque material. The ratio of the intensities of the reflected and the incident light.

A

reflectance

64
Q

A _____ substance is one that transmit part and reflects part of the light incident on it.

A

translucent

65
Q

Is 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.

A

Color

66
Q

Is the geometrically selective reflectance of a surface responsible
for its shiny or lustrous appearance.

A

Gloss

67
Q

Percentage of transmitted light that in passing through the specimen deviates from the incident beam by forward

A

Haze

68
Q

Is defined as the state permitting perception of objects through or
beyond the specimen. Refers to their degree of clarity or opacity, or how much they allow light to pass through them.

A

Transparency

69
Q

Refers to the ability of a polymer material to resist the flow of electrical current.

A

Resistivity

70
Q

Is a measure of a material’s ability to store electric charge.

A

dielectric constant

71
Q

Is a measure of its ability to sustain high-voltage differences without current breakdown.

A

dielectric strength

72
Q

Is 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.

A

Arc resistance

73
Q

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.

A

cracking

74
Q

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.

A

crazing

75
Q

Directly measured as the rate of transfer of vapor through unit thickness of the polymer in film form, per unit area and pressure difference across the film.

A

Permeability

76
Q

Refers to the ability of a polymer material to allow certain gases or vapors to pass through it.

A

Vapor permeability

77
Q

Refers to the process of degradation of polymers, or large molecules, due to exposure to external factors such as sunlight, temperature, and chemicals.

A

Weathering

Polymer engineering (6 decks)

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