CORPORATE TRAINING AND PLANNING Cellulose Plastics

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).

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

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 itsacetyl groups. Plastic grade CA contains 38 to 40% acetyl.

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.

CORPORATE TRAINING AND PLANNING When A is and B is Plastic is H HCellulose —C—CH 3 —C—CH 3 Cellulose acetate || || O O —C—CH 3 —C—CH 2 —CH 3 Cellulose acetate propionate || || O O —C—CH 3 —C—CH 2 —CH 2 —CH 3 Cellulose acetate butyrate || || O O —C—CH 2 —CH 3 —C—CH 2 —CH 3 Cellulose propionate || || O O —CH 2 —CH 3 —CH 2 —CH 3 Ethyl cellulose —NO 2 —NO 2 Cellulose Nitrate

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 C but the process was difficult to control.  With further research various new techniques of manufacturing of cellulose acetate are developed.

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.

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

CORPORATE TRAINING AND PLANNING Properties of Cellulose acetate Name ValueUnit Specific gravity Tensile Strength40MPa Tensile modulus2174MPa Flexural modulus1794MPa Elongation at break38% Impact Strength (Izod )160J/m HardnessR62--- HDT (under 1.82 MPa load.)61°C Melting point °C Glass transition temperature157°C Dielectric Strength13.4KV/mm

CORPORATE TRAINING AND PLANNING Applications Tool handles Spectacles CA Different applications

CORPORATE TRAINING AND PLANNING Bleached Wood Pulp % H 2 SO 4 Pretreated for 12 hours Drying with Acetic acid Etherification of treated cellulose with mixture of Butyric acid and acetic anhydride + H 2 SO 4 ( Catalyst) Cellulose acetate butyrate Cellulose Acetate Butyrate (CAB)

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

CORPORATE TRAINING AND PLANNING Properties of Cellulose Acetate Butyrate Name ValueUnit Specific gravity Tensile Strength34.5MPa Tensile modulus1725MPa Flexural modulus1449MPa Elongation at break50% Impact Strength (Izod )187J/m HardnessR75--- HDT (under 1.82 MPa load.)65°C Dielectric Strength13.4KV/mm

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.

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.

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.

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.

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.

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.