Xanthate Viscose Process

Question 1

steps

Answer 1

1) cellulose + NaOH takes off C2 H+
2) add CS2 (l) to form orange “viscose”
3) add dilute H2SO4 to regenerate cellulose

Question 2

chemical properties of the cellulose xanthate

Answer 2

H-bonding is decreased

if you add heat it begins to flow

H2O soluble

Question 3

how to process

Answer 3

spinneret (hole) - soln extruded through = rayon fibers

slit - soln extruded through = film

1) filter
2) dilute H2SO4 to regenerate

Question 4

physical changes during processing

Answer 4

stretching orients chains so they’re more organized

this increases strength b/c crystalline structure

“cellulose of greater strength”

Question 5

is this process sustainable?

Answer 5

yes, it’s biodegradable

all solvents are recyclable (Tensel/Lyocell) are bleached wood pulps

Question 6

shrinking

Answer 6

when washed in heat “memory”

Question 7

rayon family

Answer 7

viscose (bamboo, plant/tree pulps)

model (beech trees)

Question 8

which OH of cellulose is most acidic?

Answer 8

1º usually more acidic but pka ~ 14

C3 pka ~ 12

C2 pka ~ 10 (Most Acidic)

Question 9

why C2 most acidic?

Answer 9

e- density pulled away from C by 2 neighboring O groups

Question 10

do you only get a reaction at C2?

Answer 10

no you also get some C3