Triacetate and acetate are modified cellulosic fibers. Triacetate contains at least 92% acetate groups and is not hydrophilic, while acetate contains at least 76% acetate groups and is hydrophilic. Both fibers are produced from wood pulp or cotton through acetylation and hydrolysis processes, then spun into fibers. The main difference is triacetate contains 3 acetate groups per benzene ring and acetate contains 2 acetate groups with 1 hydroxyl group remaining.

1. Department of Textile Engineering
Dhaka University of Engineering and Technology(DUET), Gazipur

2. Topic Name:- Acetate fiber and Triacetate fiber
Student Information
Name:- Mahbubay Rabbani Mim
Student ID:- 175035
Semester & Year:-2/2
Subject:- Textile physics and fibrous material

3. Introduction
Acetate and triacetate are manufactured fibers which are belong to
modified cellulosic fibers. In this cellulosic fiber the main component is
cellulose acetate.
The fiber in which 92% acetate group is contained at least is called
Triacetate or primary acetate. On the other hand which contains at
least 76% acetate group is called Di-acetate or secondary acetate.
Acetate fiber → at least 76% acetate group containing.
Triacetate fiber → at least 92% acetate group containing.

4. Structure of cellulose

5. Cellulose Triacetate
In cellulose triacetate at least 92% acetate
group is exist. Here about 92% acetylation is
done and for which all the OH group is
replaced from every Benzene ring by acetate
group.
In triacetate polymer every benzene ring
contains 3 acetate group and for which it is
called Triacetate.
Triacetate is produced at initial stage in
compare to Di-acetate and for this reason it is
also called Primary acetate.

6. Cellulose Triacetate

7. Production of Triacetate
Raw materials for producing:-
i. Wood pulp or cotton linters
ii. Glacial acetic acid
iii. H2SO4 or ZnCl2
Here H2SO4 or ZnCl2 is used as catalyst.

8. Production of Triacetate
Wood pulp
+acetic acid
Dissolve in
CH2Cl2
Dry spun
Cellulose
Triacetate

9. Spinning process

10. Some Trade names with manufacturer
Trade names Manufacturer
1.Acele Du Pont, USA
2.Aceta Bayer, Germany
3.Arnel Celanase Crop Co, USA
4.Atlon Toho Rayon Co, Japan
5.Albuna Snia Viscose, Italy

11. Properties of Triacetate fiber
i. Obtained as tough solid
ii. Not soluble in Acetone that’s why nail polish doesn’t damage the
fiber and fabric.
iii. It is soluble in toxic and expensive solvents like CHCl3 (Chloroform).
iv. It is not hydrophilic at all.
v. Drip drying recommended.
vi. Soften at 200 degree centigrade that’s why cool iron is used.

12. Cellulose Acetate or Di-Acetate
• Cellulose acetate contains at least 76% acetate group. In that polymer
about 34% Hydroxyl group is available. After 76% acetylation of
cellulose, it is obtained.
• It is called Di-Acetate because of containing 2 acetate group.
• It is obtained from cellulose triacetate after partial hydrolysis that’s
why it is called Secondary Acetate.

13. Structure of Acetate

14. Structure of Di-Acetate
• Here after acetylation and hydrolysis
only 1 hydroxyl group is exist and 2
acetate group is contained also in
every benzene ring.

15. Production of Acetate
Wood pulp +
Acetic acid
Convert to
cellulose di
acetate flakes
Dissolve in
aceton at 56
degree
centigrade
Dry spun
Cellulose
acetate

16. Production of Acetate

17. Production of Acetate

18. Manufacturing stages
• Acetylation process
• Hydrolysis
• Preparation of dope solution
• Spinning

19. Hydrolysis process for Di-Acetate
• Di-acetate is formed from tri-acetate and for forming this
• At frirst triacetate is stored for ageing.
• Then Acetic acid and water and sulfuric acid are added and allowed
for 10-12 hours.
• Here during this period partial conversion of acetate groups to
hydroxyl group is done.
• The mixture is then diluted with water and stirred constantly.
• Here careful control should be maintained.
• Then the secondary acetate is separate in form of white flakes.

20. Hydrolysis process for Di-Acetate
• After separation of white flake, the water is removed and reaction
vessel is again filled with fresh water. Here water is changed for
several times for obtaining the formed di-acetate.
• When all the formed acetate is centrifuged then the excess water is
removed and then dry the flakes.

21. Major manufacturer of acetate fiber
• Celanese
• Eastman
• Viscocel
• Mitsubishi Rayon

22. Properties of Acetate fiber
• Crystallinity=40%
• Tenacity= 2.5 g/d
• elongation =16-18%
• It is hydrophilic and M.R=6%-7%
• Heat sensitive and soften at 200 degree centigrade. So cool iron is
used.
• Soluble in acetone and that’s why it is damaged by nail polish.
• Degraded by acids but resistant to alkalis.

23. Difference between Triacetate and Acetate
Triacetate Acetate or Di-acetate
• Contain 3 acetate groups. • Contains 2 acetate groups.
• No OH groups is present. • Only one OH group is present.
• More crystalline. • Less crystalline.
• High melting point. • Low melting point.
• It is not hydrophilic. • It is hydrophilic.
• It is called primary acetate. • It is called secondary acetate.

24.  End uses of Acetate and Triacetate
Triacetate
• Major used in cloth for lining.
Acetate
• Woven.
• Satin, Crepes, Taffetas, velour.
• Bed sheets, pillow cover.
• Weeding dress