5. FILLERS/EXTENDERS/REINFORCEMENT
To reduce the cost of finished plastics
To improve hardness ,tensile strength ,water resistance,
electrical insulating properties.
Enhance mechanical strength
E.g Asbestos-heat & corrosion resistance
Carbon black-tensile strength in natural rubber
Quartz ,mica -hardness
Saw dust ,paper pulp ,wood flour, graphite, cotton fiber,
pumice
6. LUBRICANTS
To impart the flawless glossy finish
Prevent plastic material from sticking
E.g waxes ,oils, soaps , stearates, oleates
7. CATALYST/ACCELERATORS
Required only for thermosetting resins
Accelerates the polymerization reaction
E.g hydrogen peroxide, benzoyl peroxide, metals
like Cu,Pb, ammonia and its salts.
8. STABILIZERS
Improve the thermal stability during processing
E.g White lead, Lead chromate, lead silicate
22. EXTRUSION MOULDING
The plastic granules are
moved down by the feed
screw and heated up.
The molten plastic is
forced through the
series of dies.
23. The plastic extrusion is
cooled by passing it
through a water bath or
jets of air.
The extrusion continues
until it reaches its
predetermined length.
It is then cut off to
length and the cycle of
operations continues.
36. PREPARATION
(i) Hydrogenation Of Acetylene
H 2 / Pd
CH CH CH 2 CH 2
Acetylene Ethylene
(ii) Dehydration of ethanol
Dehydration
Catalyst
CH 3CH 2OH CH 2 CH 2 H 2O
Ethanol Ethylene
(iii) Dehydrogenation of ethane
Dehydrogen
ation
Catalyst
CH 3 CH 3 CH 2 CH 2 H2
Ethane Ethylene
37. TYPES OF PE
LDPE
BenzoylPeroxide
80 250 C
1500 atm
n[CH 2 CH 2 ] [ CH 2 CH 2 ]n
HDPE
Al ( C2 H 5 ) 3
120 C
6 7 atm
n[CH 2 CH 2 ] [ CH 2 CH 2 ]n
38. Low Density PE High Density PE
Obtained at High P Obtained at low P
Branched Structure Linear structure
Low density 0.91-0.925 High density 0.95-
g / cm 3 0.97 g / cm 3
Low M.P(115ºC)
Low Crystallinity High M.P(135ºC)
High Water & gas High Crystallinity
permeability Low Water & gas
Used for making toys , permeability
mugs , carry bags. For making milk bottles
,industrial containers ,
for domestic water &
gas piping.
39.
40. PROPERTIES OF PE
Rigid, waxy, white, translucent, non-polar material
Chemical resistance to strong acids, alkalis and salt
solution
Good electrical insulator
Resistant to atmospheric conditions
46. POLY VINYL CHLORIDE (PVC)
Prepared by polymerization of VC
Free radical chain polymerization
Heated in water Emulsion with catalyst under
pressure.
47. PREPARATION OF VINYL CHLORIDE
60 80 C
MetalChlorideCatalyst
CH CH HCl CH 2 CHCl
Acetylene Vinyl Chloride
48. PROPERTIES OF PVC
Colorless & odorless powder
Chemically inert & nonflamable
High resistance to light, Atmospheric Oxygen, Acids
& Alkalis.
Soluble in Chlorate
