Test 3 Flashcards
nylon is most degraded by
ultraviolet light
acid (low ph)
nylon can be produced with what fiber cross-sectional shapes
round
tri-lobal
hollow
nylon fibers are made using what process
melt spinning
nylon has a low elongation compared to most other textile fibers
false
at standard lab conditions nylon absorbs how much moisture content
4%
nylon is an excellent choice for carpet because
- its resilient
- when wet, it has a very low glass transition temperature
- it resists wear
nylon has high tenacity compared to what other fibers
rayon and acrylic
the melting temperature of nylon 6,6 is approximately (depending upon molecular weight)
250 c
nylon 6,6 has how many carbon atoms in the backbone of the monomer unit
12
nylon is used in what applications requiring great toughness (combining strength and elongation)
rope and tent
Fibers classified as polyester contain what chemical groups
C=O, An aromatic ring
the melting temp of polyester is approximately
250 C
polyester is most degraded by
hot concentrated alkali (high pH)
polyester has high tenacity compared to what other fibers
rayon and acrylic
polyester can be produced with what fiber cross sectional shape
round
tri-lobal
hollow
polyester fibers are made using what process
melt-spinning
at standard lab conditions polyester absorbs how much mositure content
.4%
polyester is often blended with fibers made from other polymers
true
polyester is used in what applications requiring high strength
rope
tent
marine anchor rope
polyester is an excellent choice for what end uses because of its hydrophobicity
geotextiles
fish nets
boat sails
olefin is an excellent choice for what end uses because of its resistance to uv light
carpet
geotextiles
upholstery
at standard lab conditions olefin absorbs how much moisture content
.1%
olefin fibers are made using what process
melt spinning and gel spinning
the mass density of olefin fibers contributes to what characterisitcs
it floats on water
high strength-weight ratio
high tenacity
Olefin is most degraded by
organic solvents
UV light
olefin can be produced with what fiber cross sectional shapes
round
tri-lobal
hollow
fibers classified as polyethylene contain what chemical groups
C-H
fibers classified as polypropylene contain what chemical groups
CH3 and C-H
Olefin is used in what applications requiring high strength
bail twine
rope
bags
the melting temp of polypropylene is approx
165 C
rayon has low tenacity compared to what other fibers
olefin
nylon
acrylic
rayon fibers are made using what process
wet spinning
during the production of rayon, large amount of what are produced
polluting effluent
how do you ger cellulose during production of rayon
by removing from wood pulp or another source
will the molecular weight during rayon production by reduced or gained
reduced
how will cellulose be extruded during the rayon production
cellulose must be dissolved in a solvent
rayon is most degraded by
acid (low pH)
microorganism
hot concentrated alkali (high PH)
rayon absorbs nearly twice as much moisture as cotton because
it has twice as much amorphous mass
rayon is often blended with fibers made from other polymers
true
fibers classified as rayon contain what chemical groups
C-O, CH2OH
the melting temp of rayon is approx
with decompose before it melts
at standard lab conditions rayon absorbs how much moisture content
12%
rayon differs from cotton in what ways
rayon has lower tenacity
rayon loses strength when wet
rayon has less crystallinity
acetate absorbs much less moisture than rayon bc
hydroxyl groups have been replaced by acetyl groups
acetate has low tenacity compared to what other fibers
nylon
acrylic
olefin
rayon
where does cellulose come durign acetate production
wood pulp or other source
what large amounts are produced during acetate production
polluting effluent
how is cellulose extruded during acetate production
dissolved in solvent
what happens to molecular weight in acetate production
reduced
how does acetate differ from tri-acetate
tri-acetate is more like polyester
tri-acetate has all of the hydroxyl groups acetylated
acetate is most degraded by
concentrated acid (low pH)
hot concentrated alkali (high pH)
organic solvents
acetate fibers are made using what process
dry spinning
at standard lab conditions acetate absorbs how much mositure
6.5%
acetate has low tenacity compared to what fibers
nylon
polyester
olefin
acrylic
is chain growth polymericzation used in acrylic production
yes
what happens to acrylonitrile polymer during acrylic production
dissolved in solvent
acrylic is often not blended with fibers made from other polymers and used as 100% acrylic
false
all fibers classified as arylic contain what chemical groups
CH2, CN
at standard lab conditions acrylic absorbs how much mositure content
1.5%
the melting temp of acrylic is approx
decomposes before it melts
acrylic is most degraded by
hot concentrated alkali (high pH)
hot concentrated acid (low pH)
bc it is resistant to microorganism’s and has high thermal resistance, acrylic Is used in what applications
blankets
apparel
acyrlic differs from wool in what ways
wool has lower tenacity
acrylic is hydrophonic and generates static charges
acrylic resists microorganisms and insents
acrylic is often blended with fibers made from other polymers
true
acrylic fibers are made using what processes
wet spinning
dry spinning
rubber has great abrasion resistance comapred to spandex
false
spandex is commonlu used in what products
jeans
elastomers at the molecular level are shaped like
springs
how are polyurethane fibers created
dry spinning
wet spinning
melt spinning
how do you harvest rubber
it is derived by a tree barn
kevlar and nomex have the same chemical structure
false
the following fibers have great fiber resistance
Nome
the following fibers have a high tensile strength
spectra, Kevlar, HDPE
nomex is commonlu used in tennis racquets to increase strength
false
kevalr and nomex have the same chemical formula
true