Cellulose polymer

1. CORPORATE TRAINING AND PLANNING
Cellulose Plastics

2. CORPORATE TRAINING AND PLANNING
Cellulose Plastics
Introduction
 Cellulose is a natural polymer produced from wood via
wood pulp.
 Woven grade cotton contains about 90% cellulose while
an average wood has about 50% and the balance is
composed of lignin and polysaccharides.
 Cellulose resins include four organic esters, cellulose
acetate (CA), cellulose acetate butyrate (CAB),
cellulose acetate propionate (CAP) and cellulose acetate
triacetate (CAT).

3. CORPORATE TRAINING AND PLANNING
 In 1927, Eastman Kodak Co. commercialized
cellulose acetate into photographic film base.
 Molding grade of CA was introduced in 1935.
 In 1938, Eastman introduced CAB.
 CAP was introduced in 1960.

4. CORPORATE TRAINING AND PLANNING
Polymerization
 The cellulose esters are prepared by reacting
chemical cellulose with organic acids and anhydrides
using sulfuric acid as a catalyst.
 In the standard synthesis of CA, the reaction
proceeds with acetic acid and acetic anhydride to the
triester stage. CA is prepared by hydrolyzing the
triester to remove some of its acetyl groups. Plastic
grade CA contains 38 to 40% acetyl.

5. CORPORATE TRAINING AND PLANNING
 The propionate and butyrate esters are made by
substituting propionic acid and propionic anhydride
or butyric acid and butyric anhydride for some of the
acetic acid and acetic anhydride.
 Plastic granules of CAP contain 39 to 47% propionyl
and 2 to 9% acetyl. CAB contains 26 to 39% butyryl
and 12 to 15% acetyl.

6. CORPORATE TRAINING AND PLANNING
When A is and B is Plastic is
H H Cellulose
—C—CH3 —C—CH3 Cellulose acetate
|| ||
O O
—C—CH3 —C—CH2—CH3 Cellulose acetate propionate
|| ||
O O
—C—CH3 —C—CH2—CH2—CH3 Cellulose acetate butyrate
|| ||
O O
—C—CH2—CH3 —C—CH2—CH3 Cellulose propionate
|| ||
O O
—CH2—CH3 —CH2—CH3 Ethyl cellulose
—NO2 —NO2 Cellulose Nitrate

7. CORPORATE TRAINING AND PLANNING
Cellulose Esters
Cellulose Acetate
Introduction
 Manufacturing of cellulose acetate was done in 1865 using a
process in which cotton was heated with acetic anhydride in
sealed tube at 130-1400C but the process was difficult to
control.
 With further research various new techniques of
manufacturing of cellulose acetate are developed.

8. CORPORATE TRAINING AND PLANNING
 One of the methods available today is homogenous
acetylation.
 In this process cellulose is pretreated with glacial
acetic acid to open up the cellulosic matter.
 After pretreating, acetylation is done by mixing
pretreated cellulose with acetylating agent like
acetic anhydride, a catalyst like concentrated
sulphuric acid and acetic acid as diluent.

9. CORPORATE TRAINING AND PLANNING
Properties
- High water absorption
- Poor electrical insulation characteristics
- Limited aging resistance
- Limited heat resistance
- Dissolved by wide variety of reagents

10. CORPORATE TRAINING AND PLANNING
Properties of Cellulose acetate
Name Value Unit
Specific gravity 1.28 --
Tensile Strength 40 MPa
Tensile modulus 2174 MPa
Flexural modulus 1794 MPa
Elongation at break 38 %
Impact Strength (Izod ) 160 J/m
Hardness R62 ---
HDT (under 1.82 MPa load.) 61 °C
Melting point 240-260 °C
Glass transition temperature 157 °C
Dielectric Strength 13.4 KV/mm

11. CORPORATE TRAINING AND PLANNING
Applications
Tool handles
Spectacles
CA Different applications

12. CORPORATE TRAINING AND PLANNING
Bleached Wood Pulp
+ 40-50% H2SO4
Pretreated for 12 hours
Drying with Acetic acid
Etherification of treated cellulose with mixture of Butyric acid
and acetic anhydride + H2SO4 ( Catalyst)
Cellulose acetate butyrate
Cellulose Acetate Butyrate (CAB)

13. CORPORATE TRAINING AND PLANNING
Properties
- Good toughness
- Excellent appearance
- Giving good coating with hard glossy surface
- Lower water absorption
- Better flow properties
- Lower density

14. CORPORATE TRAINING AND PLANNING
Properties of Cellulose Acetate
Butyrate
Name Value Unit
Specific gravity 1.19 --
Tensile Strength 34.5 MPa
Tensile modulus 1725 MPa
Flexural modulus 1449 MPa
Elongation at break 50 %
Impact Strength (Izod ) 187 J/m
Hardness R75 ---
HDT (under 1.82 MPa load.) 65 °C
Dielectric Strength 13.4 KV/mm

15. CORPORATE TRAINING AND PLANNING
Applications
- Toys, tools handles, tabular keys, telephone
housing, pipes for conveying water, outdoor display
signs, vacuum formed products and protective
coating for metals.

16. CORPORATE TRAINING AND PLANNING
Cellulose Acetate Propionate
- Cellulose Acetate Propionate having shorter side
chain and it is harder stiffer, and posses higher
tensile strength than Cellulose Acetate Butyrate.
- Easy to vacuum form and also tend to be used for
applications like tool handles, safety lockers,
steering wheels, etc.

17. CORPORATE TRAINING AND PLANNING
Properties
- Cellulose Acetate Propionate have shorter side
chain and it is harder, stiffer and possess higher tensile
strength than Cellulose Acetate Butyrate. Like
cellulose acetate butyrate, this is easy to vacuum form
and also tends to be used for applications like tool
handles, safety lockers, steering wheels, etc.

18. CORPORATE TRAINING AND PLANNING
Cellulose Nitrate
- Cellulose Nitrate is manufactured by the
reaction between cellulose, nitric acid and
sulphuric acid.
- It is possible to vary degree of etherification
according to the root hydroxyl group which is
replaced by nitrate group.
- Fully nitrated cellulose, cellulose tri-nitriate
is an explosive.
- Cellulose nitrate is precipiticised with
camphor in order to make it easy processable.

19. CORPORATE TRAINING AND PLANNING
Properties of Cellulose Nitrate
 Good rigidity
 Water white transparency
 Poor chemical resistance
 Reasonable toughness
 Capable of forming highly attractive multi-coloured
sheeting
 Highly inflammable.

20. CORPORATE TRAINING AND PLANNING
Applications
 The one time important application was in
photographic film.
 Today the principal outlet are knife handles,table
tennis ball and spectacle frames.