Chapter 15 Acetate and
Triacetate Fibers
Yiping Qiu
Donghua University
Introduction
? Fibers in which forming substance is cellulose
acetate where not less than 92% of hydroxyl
groups are acetylated,replacing -OH groups with -
COCH3.
? Acetate,2 of 3 -OH groups in each 6-member ring
are acetylated; ~2.5
? Triacetate,Nearly all -OH groups are replaced
2.91~2.96
? Major use,lining fabrics for suits,coats,draperies
Structures
? Surface,straited
? Cross-section,lobed
? Skin-core structure
? DP,250-300
? Much less H-bond than in rayon
Properties
? Acetate,hydrophilic,thermoplastic
? Triacetate,hydrophobic,higher melting and
softening temperature,high crystallinity
? Wrinkle easily in hot water,dry cleaning
only
? Swells in water,mechanical properties
change in water
? Resist to weak alkali and acids
? Can be bleached
Properties
? Soluble in acetone
? Degrade in UV light
? Burns,melts,forms black beads with
vinegar like odder
Production
? Similar to cellulose rayon for the first a few
steps
? Cellulose mixed with acetic acid and acetic
anhydride,a sulfuric acid catalyst is added
? acetylation takes place
? degradation of the polymer making DP low
? triacetate is made first
? when water added,some acetyl groups are
removed
Grades for test 1
number of students
0
2
4
6
8
10
12
14
16
18
20
0 - 9 10 19 20
29
30 -
39
40 -
49
50 -
59
60 -
69
70 -
79
80 -
89
90 -
100
number
Chapter 16 Nylon Fibers
Yiping Qiu
Donghua University
Introduction
? Nylon,man-made fibers in which fiber forming
substance is any long-chain synthetic polyamide in
which less than 85% of the amide linkages are
attached to 2 aromatic rings
? Invented in 1938 in Du Pont
? Largest market,carpet fiber 80% of market
? 14% industrial and consumer products,tire cord,
fabrics and ropes
? 11% apparel
Introduction
? Types,
– Mostly,Nylon 6 and Nylon 6,6
– Small amount,nylon 3,nylon 4,nylon 5,
nylon 7,nylon 8,nylon 12,nylon 4,6,
nylon 6,10
Structure
? Polymerization,condensation,eliminating a H2O
molecule
? Functional group,amide group
? Molecular configuration,linear zigzag molecules
forming well closely packed pleated sheets
? IMF,H-bond
? Crystallinity,High 65~86%
? Cross-sectional and longitudinal shape,can be any
thing
Properties
? Tenacity,high due to high orientation and
crystallinity
? Elongation,high due to zigzag structure
? Recovery,high due to zigzag
? Energy of rupture,high due to high tenacity and
high elongation,one of the toughest materials
? Flexibility,high due to zigzag
? Abrasion resistance,high
? Water absorption,highest among all synthetic
fibers
Properties
? Smooth round cross-section and uniformity permit
close packing
? Swells when absorbing moisture
? Static,not enough water absorption
? Low specific gravity,1.14g/cc
? Resilience,high,wrinkle free
? Can be laundered but not easy to clean
? Vulnerable to degradation in acids
? low resistance to sunlight
? melts and drips
Chapter 17 Polyester Fibers
Yiping Qiu
Donghua University
Introduction
? Manufactured fibers in which fiber forming
substance is any long-chain polymer
composed of at least 85% by weight of a
substituted aromatic carboxylic acid,
including but not restricted to substituted
terephthalic units
? Generic group members:
– PET (polyethylene terephthalate) ~95%
Introduction
? PCDT,poly(1,4-cyclohexylene
dimethylene),Eastman Kodak
? PEB,poly(ehtylene oxybenzoate),produced
in Japan,70’s and 80’s
Structure
? Smooth,even diameter
– diameter generally 12-25 mm
– white or off-white colors
? Intermolecular forces:
– dipole-dipole between benzene rings
? Linear polymer,DP 115-140
– Crystallinity,35%
– Orientation,very oriented
Properties
PET
? High tenacity due to high orientation
? High failure elongation
? Elastic recovery
– High with low stress,97% at 2% strain,
– Low with high stress because dipole-dipole bonding is
not strong enough to hold,leading to intermolecular
slippage
? Low compressional resilience,not good for carpet
fiber
Properties
? Very low moisture regain
? Low level of wicking due to hydrophobic surface
? High electrical resistivity,static charge likely at
low humidity
? Medium specific gravity
? Pilling
? High dimensional stability
? High Tm 450~500 degree F
Properties
? Resistant to acids,potentially degrades in
concentrated alkalies
? No UV degradation
? Flammable with black smoke
? Melt drip
? Best thermal resistant among all general use
synthetics
Properties
PCDT
? Lower tenacity and elongation
? Superior elastic recovery
? Better compressional resilience,good for end uses
such as carpets,rugs,knitwear and fiberfill
? Less pilling due to lower tenacity
Production
?Polymerization
?Form chips
?melt spinning
?drawing
?heat setting to increase crystallinity and
orientation,reduce elongation and shrinkage
Modification
?High tenacity for tire cord (higher DP and
crystallinity)
?Wicking
?Sheath-core,polyester core,low melt polymer
sheath
?Du Pont Coolmax,20% more surface area and
maybe hydrophilic treated for wicking
?Dupont Thermax,hollow fibers,excellent thermal
insulation and 20% weight reduction
Chapter 18 Olefin Fibers
Yiping Qiu
Donghua University
Introduction
? Polypropylene and polyethylene or
copolymer of ethylene and propylene
? End uses:
– 52% used in carpets and rugs
– 4% interior textile products
– 43% industrial and consumer products
– 0.5% apparel
Polymerization
? Addition or chain growth polymerization
from ethylene or propylene
C = C
H
H
H
H H
C = C
H
H
H
CH
3
H
Eth y len e P r o p y le n e
C
_
C
H H H
H H
( )
n
C
_
C
HH H
CH
3
H
( )
n
Structures
? Intermolecular forces:
– Van der Waals
? Crystallinity,50-65%
? Composed of fibrils
Properties
? Tenacity,high
– linear molecules,easy to orient
? Elongation,medium but depends on
orientation
? Elastic recovery,high
? Abrasion resistance,high due to slick
surface or low surface energy
? Flammability,low due to melting
Properties
? Toughness (work of rupture),high
? Initial modulus,depends on orientation,in
general medium
? Moisture absorption,none
? Melting and glass transition temperature
– PE Tm = 130° C,Tg = -120 ° C
– PP Tm = 170° C,Tg = -10 ° C
? Specific density,0.9 - 0.92
Chapter 19 Acrylic Fibers
Yiping Qiu
Donghua University
Introduction
? Invented in conceptually in 1893
? Produced initially in 1944 and full scale in
1950
? End uses:
– 75% in apparel
– 18% household
– 7% Industrial and consumer textiles
Polymerization
? Addition or chain growth
? Homopolymer,polyarylonitrile strong but
compact and highly oriented
– virtually impossible to dye
? Copolymers,other types of monomers are
included for a dyeable fiber and easier to
process,
– e.g,acrylic acid and vinylpyrrolidone
– most acrylic fibers are copolymers
Structure
? Microscopic
– cross-section,
? dog-bone shaped
? kidney-bean shaped
? round
– Longitudinal
? uniform diameter
? rod-like shape
Structure
? Molecular
– DP = 1000
– IMF,dipole-dipole interaction between nitrile
groups -C?N
– Crystallinity is not well-defined
Properties
? Mechanical properties similar to wool but
stronger
? Medium tenacity,better than wool
? Failure strain,medium
? High elastic recovery at low strain level 90 -
95% at 1 % strain
? Moderate abrasion resistance
Properties
? Bulky,tend to crimp
? Wick but do not absorb water
? Low specific density,1.12 - 1.19 g/cm3
? Static electricity built up
Difference between three types of
yarns
? Ring spun yarn
? Rotor spun yarn
? Air-jet spun yarn
? What are the factors determining yarn
mechanical properties?
Review for test 2
? Structures of all the fibers covered so far
? Properties of all the fibers covered so far
? Why do the fibers perform differently
? Specific problems for different fibers
? Typical end uses for each fiber
? Yarn structure and property relationship
Triacetate Fibers
Yiping Qiu
Donghua University
Introduction
? Fibers in which forming substance is cellulose
acetate where not less than 92% of hydroxyl
groups are acetylated,replacing -OH groups with -
COCH3.
? Acetate,2 of 3 -OH groups in each 6-member ring
are acetylated; ~2.5
? Triacetate,Nearly all -OH groups are replaced
2.91~2.96
? Major use,lining fabrics for suits,coats,draperies
Structures
? Surface,straited
? Cross-section,lobed
? Skin-core structure
? DP,250-300
? Much less H-bond than in rayon
Properties
? Acetate,hydrophilic,thermoplastic
? Triacetate,hydrophobic,higher melting and
softening temperature,high crystallinity
? Wrinkle easily in hot water,dry cleaning
only
? Swells in water,mechanical properties
change in water
? Resist to weak alkali and acids
? Can be bleached
Properties
? Soluble in acetone
? Degrade in UV light
? Burns,melts,forms black beads with
vinegar like odder
Production
? Similar to cellulose rayon for the first a few
steps
? Cellulose mixed with acetic acid and acetic
anhydride,a sulfuric acid catalyst is added
? acetylation takes place
? degradation of the polymer making DP low
? triacetate is made first
? when water added,some acetyl groups are
removed
Grades for test 1
number of students
0
2
4
6
8
10
12
14
16
18
20
0 - 9 10 19 20
29
30 -
39
40 -
49
50 -
59
60 -
69
70 -
79
80 -
89
90 -
100
number
Chapter 16 Nylon Fibers
Yiping Qiu
Donghua University
Introduction
? Nylon,man-made fibers in which fiber forming
substance is any long-chain synthetic polyamide in
which less than 85% of the amide linkages are
attached to 2 aromatic rings
? Invented in 1938 in Du Pont
? Largest market,carpet fiber 80% of market
? 14% industrial and consumer products,tire cord,
fabrics and ropes
? 11% apparel
Introduction
? Types,
– Mostly,Nylon 6 and Nylon 6,6
– Small amount,nylon 3,nylon 4,nylon 5,
nylon 7,nylon 8,nylon 12,nylon 4,6,
nylon 6,10
Structure
? Polymerization,condensation,eliminating a H2O
molecule
? Functional group,amide group
? Molecular configuration,linear zigzag molecules
forming well closely packed pleated sheets
? IMF,H-bond
? Crystallinity,High 65~86%
? Cross-sectional and longitudinal shape,can be any
thing
Properties
? Tenacity,high due to high orientation and
crystallinity
? Elongation,high due to zigzag structure
? Recovery,high due to zigzag
? Energy of rupture,high due to high tenacity and
high elongation,one of the toughest materials
? Flexibility,high due to zigzag
? Abrasion resistance,high
? Water absorption,highest among all synthetic
fibers
Properties
? Smooth round cross-section and uniformity permit
close packing
? Swells when absorbing moisture
? Static,not enough water absorption
? Low specific gravity,1.14g/cc
? Resilience,high,wrinkle free
? Can be laundered but not easy to clean
? Vulnerable to degradation in acids
? low resistance to sunlight
? melts and drips
Chapter 17 Polyester Fibers
Yiping Qiu
Donghua University
Introduction
? Manufactured fibers in which fiber forming
substance is any long-chain polymer
composed of at least 85% by weight of a
substituted aromatic carboxylic acid,
including but not restricted to substituted
terephthalic units
? Generic group members:
– PET (polyethylene terephthalate) ~95%
Introduction
? PCDT,poly(1,4-cyclohexylene
dimethylene),Eastman Kodak
? PEB,poly(ehtylene oxybenzoate),produced
in Japan,70’s and 80’s
Structure
? Smooth,even diameter
– diameter generally 12-25 mm
– white or off-white colors
? Intermolecular forces:
– dipole-dipole between benzene rings
? Linear polymer,DP 115-140
– Crystallinity,35%
– Orientation,very oriented
Properties
PET
? High tenacity due to high orientation
? High failure elongation
? Elastic recovery
– High with low stress,97% at 2% strain,
– Low with high stress because dipole-dipole bonding is
not strong enough to hold,leading to intermolecular
slippage
? Low compressional resilience,not good for carpet
fiber
Properties
? Very low moisture regain
? Low level of wicking due to hydrophobic surface
? High electrical resistivity,static charge likely at
low humidity
? Medium specific gravity
? Pilling
? High dimensional stability
? High Tm 450~500 degree F
Properties
? Resistant to acids,potentially degrades in
concentrated alkalies
? No UV degradation
? Flammable with black smoke
? Melt drip
? Best thermal resistant among all general use
synthetics
Properties
PCDT
? Lower tenacity and elongation
? Superior elastic recovery
? Better compressional resilience,good for end uses
such as carpets,rugs,knitwear and fiberfill
? Less pilling due to lower tenacity
Production
?Polymerization
?Form chips
?melt spinning
?drawing
?heat setting to increase crystallinity and
orientation,reduce elongation and shrinkage
Modification
?High tenacity for tire cord (higher DP and
crystallinity)
?Wicking
?Sheath-core,polyester core,low melt polymer
sheath
?Du Pont Coolmax,20% more surface area and
maybe hydrophilic treated for wicking
?Dupont Thermax,hollow fibers,excellent thermal
insulation and 20% weight reduction
Chapter 18 Olefin Fibers
Yiping Qiu
Donghua University
Introduction
? Polypropylene and polyethylene or
copolymer of ethylene and propylene
? End uses:
– 52% used in carpets and rugs
– 4% interior textile products
– 43% industrial and consumer products
– 0.5% apparel
Polymerization
? Addition or chain growth polymerization
from ethylene or propylene
C = C
H
H
H
H H
C = C
H
H
H
CH
3
H
Eth y len e P r o p y le n e
C
_
C
H H H
H H
( )
n
C
_
C
HH H
CH
3
H
( )
n
Structures
? Intermolecular forces:
– Van der Waals
? Crystallinity,50-65%
? Composed of fibrils
Properties
? Tenacity,high
– linear molecules,easy to orient
? Elongation,medium but depends on
orientation
? Elastic recovery,high
? Abrasion resistance,high due to slick
surface or low surface energy
? Flammability,low due to melting
Properties
? Toughness (work of rupture),high
? Initial modulus,depends on orientation,in
general medium
? Moisture absorption,none
? Melting and glass transition temperature
– PE Tm = 130° C,Tg = -120 ° C
– PP Tm = 170° C,Tg = -10 ° C
? Specific density,0.9 - 0.92
Chapter 19 Acrylic Fibers
Yiping Qiu
Donghua University
Introduction
? Invented in conceptually in 1893
? Produced initially in 1944 and full scale in
1950
? End uses:
– 75% in apparel
– 18% household
– 7% Industrial and consumer textiles
Polymerization
? Addition or chain growth
? Homopolymer,polyarylonitrile strong but
compact and highly oriented
– virtually impossible to dye
? Copolymers,other types of monomers are
included for a dyeable fiber and easier to
process,
– e.g,acrylic acid and vinylpyrrolidone
– most acrylic fibers are copolymers
Structure
? Microscopic
– cross-section,
? dog-bone shaped
? kidney-bean shaped
? round
– Longitudinal
? uniform diameter
? rod-like shape
Structure
? Molecular
– DP = 1000
– IMF,dipole-dipole interaction between nitrile
groups -C?N
– Crystallinity is not well-defined
Properties
? Mechanical properties similar to wool but
stronger
? Medium tenacity,better than wool
? Failure strain,medium
? High elastic recovery at low strain level 90 -
95% at 1 % strain
? Moderate abrasion resistance
Properties
? Bulky,tend to crimp
? Wick but do not absorb water
? Low specific density,1.12 - 1.19 g/cm3
? Static electricity built up
Difference between three types of
yarns
? Ring spun yarn
? Rotor spun yarn
? Air-jet spun yarn
? What are the factors determining yarn
mechanical properties?
Review for test 2
? Structures of all the fibers covered so far
? Properties of all the fibers covered so far
? Why do the fibers perform differently
? Specific problems for different fibers
? Typical end uses for each fiber
? Yarn structure and property relationship
