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Polymer engineering > CHARACTERIZATION, ANALYSIS, AND TESTING > Flashcards

CHARACTERIZATION, ANALYSIS, AND TESTING Flashcards

1
Q

analytical branch of polymer science

A

Polymer characterization

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2
Q

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

A

Polymer characterization

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3
Q

The information obtained from polymer characterization can also be
used for

A

process control and product quality assessment.

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4
Q

Characterization techniques are typically used to determine

A

molecular mass, molecular structure, morphology,
thermal properties, and mechanical properties

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5
Q

____________ molecular weights are observed in polymers with
very long chain

A

extremely large

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6
Q

The distribution of molecular masses can be summarized by the

A

number average molecular weight, weight average molecular weight,
and polydispersity

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7
Q

Some of the most common methods for determining these
parameters are

A

colligative property measurements, static light
scattering techniques, viscometry, and size exclusion
chromatography

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8
Q

There are four molecular weight
averages in common use

A

number-average molecular
weight, Mn
; the weight-average
molecular weight, Mw
; the zaverage molecular weight, Mz
;
and the viscosity-average
molecular weight, Mv

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9
Q

involves a count of the number
of molecules of each species, NiMi
, summed over i, divided by the total
number of molecules

A

The number-average molecular weight, Mn

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10
Q

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

A

monodisperse

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11
Q

commonly used
as a simple measure of the polydispersity of the polymer sample

A

Mw/Mn polydispersity index (PDI)

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12
Q

Determination of
Molecular Weight

A
  1. end group analysis
  2. measurement of colligative properties
  3. light scattering
  4. Ultracentrifugation
  5. dilute solution viscosity
  6. gel permeation chromatography (GPC)
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13
Q

chemical method use for calculating the numberaverage 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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14
Q

end-group analysis is limited to the determination of polymers with a molecular
weight of

A

less than about 20,000

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15
Q

methods of analysis under end-group analysis

A

✓Titrimetric method
✓Nuclear magnetic resonance (NMR)
✓mass spectrometry
✓vibrational spectrometry, like infrared and raman spectroscopy

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16
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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17
Q

colligative properties include

A

boiling point elevation, freezing point depression,
and osmotic pressure.

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18
Q

Boiling point of the solution is __________ than
the pure solvent.

A

higher

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19
Q

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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20
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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21
Q

most important among
all colligative properties for the determination of
molecular weights of synthetic polymers

A

osmotic pressure

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22
Q

technique for the
determination of molecular masses of polymers
by means of osmosis.

A

Membrane osmometry

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23
Q

Membrane osmometry is useful to determine
Mn about

A

20,000-30,000 g/mol and less than
500,000 g/mol

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24
Q

important
technique for the determination of weight-average molecular weight, M

A

Light-Scattering
Method

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25
Q

absolute method of molecular weight
measurement

A

Light-Scattering Method

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26
Q

When polarizable particles are placed in the oscillating electric field of a
beam of light, the ____________ occurs

A

light scattering

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27
Q

The intensity of scattered light relies on the

A

concentration, size and polarizability

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28
Q

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.

A

Static light scattering

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29
Q

The scattering intensity of the laser beam is then measured
at a fixed angle

A

90 degrees

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30
Q

measure of the opposing force of material to
flow

A

viscosity

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31
Q

gives the relationship between viscosity and
average molecular weight:

A

Mark-Houwink equation

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32
Q

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

A

Ubbelohde
viscometer

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33
Q

extremely powerful method for determining the
complete molecular weight distribution and
average molecular weights

A

Gel permeation chromatography (GPC)

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34
Q

used to purify and characterize
low-molecular-weight polymers

A

Ultracentrifuges

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35
Q

The ultracentrifuge is operated at extremely high
speeds up to

A

70000 rpm

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36
Q

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

A

Polymer morpholog

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37
Q

CHEMICAL
ANALYSIS OF
POLYMERS

A
  1. Mass Spectrometry
  2. Gas Chromatography
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38
Q

The
polymer is allowed to react to form low-molecular-weight fragments that are
condensed at liquid-air temperature

A

Mass Spectrometry

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39
Q

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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40
Q

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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41
Q

t is an analytical technique used to separate the
chemical components of a sample mixture and then
detect them to determine their presence or absence.

A

Gas Chromatography

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42
Q

analytical method that combines the features
of gas-chromatography and mass spectrometry to
identify different substances within a test sample

A

Gas chromatography–mass spectrometry (GC–MS)

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43
Q

SPECTROSCOPIC METHODS

A
  1. Infrared Spectroscopy
  2. Nuclear Magnetic Resonance
    (NMR) spectroscopy
  3. Electron Paramagnetic
    Resonance Spectroscopy
  4. Ultraviolet–visible
    spectroscopy
  5. Raman spectroscopy
44
Q

analysis
of infrared light interacting with a
molecule. This can be analyzed in
three ways by measuring absorption,
emission and reflection.

A

Infrared Spectroscopy

45
Q

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)

46
Q

reliable and cost-effective analytical tool
for identification of polymers and assessment
of the quality of plastic materials

A

Fourier transform infrared spectroscopy (FTIR)

47
Q

powerful analytical technique used to study the molecular
structure, dynamics, and composition of organic and inorganic
compounds.

A

Nuclear Magnetic Resonance (NMR) spectroscopy

48
Q

The major use of___________ lies in the detection of free radicals

A

Electron Paramagnetic
Resonance Spectroscopy

49
Q

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

A

Electron Paramagnetic
Resonance Spectroscopy

50
Q

valuable technique for analyzing
polymers, providing insights into their electronic structure,
composition, and molecular interactions.

A

UV-Vis spectroscopy

51
Q

powerful qualitative and
quantitative tool with some particular advantages for the
analysis of polymers

A

Raman spectroscopy

52
Q

analytical technique used to
study molecular vibrations in materials by measuring the
scattering of light when it interacts with a sample

A

Raman spectroscopy

53
Q

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

A

X-Ray diffraction analysis (XRD)

54
Q

go-to tool for
identifying the type and crystallinity of polymer materials

A

X-Ray diffraction analysis (XRD)

55
Q

MICROSCOPY

A

1, Light
2. Electron

56
Q

valuable for examining the
texture of solid opaque
polymers

A

Light Microscopy

57
Q

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

58
Q

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

A

Phase-contrast microscopy

59
Q

t is commonly used in materials science and
polymer science to observe changes in the
morphology of polymers during phase
transitions or in response to external stimuli.

A

Phase-contrast microscopy

60
Q

powerful tool in the
study of the morphology of crystalline polymer

A

Electron Microscopy

61
Q

beam of
electrons and their wave-like characteristics to
magnify an object’s image, unlike the optical
microscope that uses visible light to magnify
images

A

electron microscope

62
Q

type of electron microscope that produces
images of a sample by scanning the surface
with a focused beam of electrons

A

scanning electron microscope (SEM)

63
Q

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.

A

transmission electron microscope (TEM)

64
Q

THERMAL ANALYSIS

A
  1. Differential Scanning Calorimetry
  2. Differential Thermal Analysis
  3. Thermogravimetric
    Analysis
  4. Thermomechanical
    Analysis
65
Q

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

66
Q

used widely for examining polymeric materials
to determine their thermal transitions.

A

Differential Scanning Calorimetry

67
Q

mportant
thermal transitions include the

A

glass transition temperature (Tg),
crystallization temperature (Tc),
and melting temperature (Tm)

68
Q

the material under study and an inert reference
are made to undergo identical thermal cycles, (i.e.,
same cooling or heating programme) while recording
any temperature difference between sample and
reference

A

Differential Thermal Analysis

69
Q

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

A

Thermogravimetric
Analysis

70
Q

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

A

Thermomechanical
Analysis

71
Q

MECHANICAL
PROPERTIES

A

a. Stress-Strain
Properties in
Tension
b. Fatigue Tests
c. Impact Tests
d. Tear
Resistance
e. Hardness
f. Abrasion
Resistance

72
Q

sually
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

73
Q

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

A

Hardness

74
Q

When plastics are used as films,
particularly in packaging applications,
their resistance to

A

tearing

75
Q

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

A

Impact tests

76
Q

Four commonly used types of impact tests
include

A

Charpy, Izod, drop-weight, and
dynamic tear tests.

77
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

78
Q

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 tests

79
Q

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

A

Tensile strength

80
Q

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

A

Yield strength

81
Q

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

A

Young’s modulus (or Young modulus)

82
Q

THERMAL
PROPERTIES

A

a. Softening
Temperature
b. Flammability

83
Q

usually tested
as the burning rate of a specified
sample.

A

Flammability

84
Q

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

A

Softening
Temperature

85
Q

OPTICAL
PROPERTIES

A

a. Transmittance and Reflectance
b. Color
c. Gloss
d. Haze
e. Transparency

86
Q

defined as the state permitting perception of objects through or
beyond the specimen

A

Transparency

87
Q

degree of clarity or opacity, or how much
they allow light to pass through them.

A

Transparency

88
Q

that percentage of transmitted
light that in passing through the
specimen deviates from the
incident beam by forwar

A

haze

89
Q

In commercial hazemeters only
light deviating more than __________
from the transmitted beam
direction is considered haze.

A

2.5o

90
Q

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

A

gloss

91
Q

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

92
Q

one that transmit part and reflects part of the
light incident on it.

A

translucent

93
Q

the ratio of the intensities of light passing through and light
incident on the specimen

A

transmittance

94
Q

ELECTRICAL
PROPERTIES

A

a. Resistivity
b. Dielectric
Constant
c. Dielectric
Strength
d. Arc Resistance

95
Q

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

96
Q

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

A

dielectric strength

97
Q

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

A

dielectric constant

98
Q

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

A

resistivity

99
Q

CHEMICAL
PROPERTIES

A

a. Resistance to Solvent
b. Vapor Permeability
c. Weathering

100
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

101
Q

product of the solubility of the gas or vapor
in the polymer and its diffusion coefficient.

A

Vapor Permeability

102
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

103
Q

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

A

Vapor permeability

104
Q

he effects of solvents on polymers may take several forms:

A

Solubility;swelling; environmental stress
cracking,;crazing

105
Q

which 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

environmental stress
cracking

106
Q

in which 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.

A

crazing

Polymer engineering (5 decks)

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