INTRODUCTION OBJECTIVES METHOD OF POLYMERIZATION FLOW DIAGRAM MODEL OF SUSPENSION POLYMERIZATION ADVANTAGES DISADVANTAGES ADVANCEMENT IN THE FIELD OFSUSPENSION POLYMERIZATION CONCLUSION

1. SUSPENSION
POLYMERIZATION
By-Er. VED PRAKASH

2. CONTENTS
1) INTRODUCTION
2) OBJECTIVES
3) METHOD OF POLYMERIZATION
4) FLOW DIAGRAM
5) MODEL OF SUSPENSION POLYMERIZATION
6) ADVANTAGES
7) DISADVANTAGES
8) ADVANCEMENT IN THE FIELD OF
SUSPENSION POLYMERIZATION
9) CONCLUSION

3. INTRODUCTION
 Suspension Polymerization is a heterogeneous radical
polymerization process that uses mechanical agitation to mix a
monomer or mixture of monomers in a liquid phase, such as
water, while the monomers polymerize, forming spheres of
polymer.
 This process is used in the production of many commercial
resins, including Poly Vinyl Chloride (PVC), a widely used
plastic styrene resins including Poly Styrene, Expanded Poly
Styrene (EPS), and High Impact Poly Styrene (HIPS), as well
as Poly Styrene Acrylonitrile (SAN) and Poly
Methylmethacrylate (PMMA).

4. OBJECTIVES
 Suspension polymerization is most commonly used as Industrial
Manufacturing method in ordr to get polymer for forming
material such as poly styrene, poly methylmethacrylate, poly
vinyl acetate, poly vinyl chloride.
 A polymer with a high degree polymerization is obtained with
the polymerization and generated polymer isolation is easy.
 Suspension polymerization is commonly used to produce
microne sized (10-1000 micrometer) polymer beads, in which the
final particle size distribution is an important end use property.
 Suspension polymerization is suitable for preparing medium to
high molecular weight products.
 Suspension polymerization is suitable for Free-radical
Polymerizatin and Poly condensation Polymerisation.

5. METHOD OF POLYMERIZATION
 In this method the water insoluble monomer is dispersed as
large droplets of size 0.1 to 1 mm in water.
 Initiators used are monomer soluble such as Dibenzoyl
peroxide.
 Thus polymer is produced in heterogeneous medium.
 The dispersion is maintained by continuous agitation and the
droplets are prevented to coalesce ( unite or merge) by adding
small quantity of stablizers.
 The stablizers used are PVA, Gelatin, Cellulose are used along
with inorganic stablizers such as Kaolin, Magnesium silicate,
Aluminium hydroxide, Calcium/Magnesium phosphate, etc.
 As it concerns with droplets, each droplet is tiny bulk reactor.

6. METHOD OF POLYMERIZATION
 The polymerization takes place inside the droplet and product
formed being insoluble in water.
 The product separated out in the form of spherical pearls or
beads of polymer.
 Hence the technique is also known as Pearl
Polymerization/Granular Polymerization/ Bead
polymerization.
 The polymer formed is isolated only by filteration of the beads
and removal of surface active agents and protective colloids by
water washing.
 Washed and dried product can be used for moulding or used as
adhesive by dissolving in a suitable solvent.

7. FLOW DIAGRAM

8. MODEL OF SUSPENSION
POLYMERIZATION

9. ADVANTAGES
 The process is comparatively cheap as it involves only water
instead of solvents.
 Viscosity increase is negligible.
 Agitation and temperature control is easy.
 Product isolation is easy since the product is insoluble in
water.
 Polymer produced may be used directly used as polymeric
suspension.
 Good heat transfer.
 The purity of obtained polymer is high.
 Suitable for preparing high molecular weight products.

10. DISADVANTAGES
 This method can be adopted only for water insoluble
monomers.
 It is difficult to control polymer size.
 Suspension polymerization is highly agitation sensitive.
 Larger volume of reactor is taken up by water.
 The method can’t be used for tacky polymers such as
elastomers because of the tendency for agglomeration of
polymer particles.
 Need extra process in washing out suspending agent/
contaminants and drying the polymer beads.
 Polymer beads may stick together and may be contaminated
with suspending agent.

11. ADVANCEMENT IN THE FIELD OF
SUSPENSION POLYMERIZATION
 Polymer Nanocomposites synthesized by suspension
polymerization technique revolutionized the field of
composites using advancements such as use of reactive
surfactants, modified initiators, advanced clay surface
modifications.
 Synthesis of macroporous polymer (PS) particles by
suspension polymerization in water in Supercritical Carbon
dioxide (sc-CO2) medium using poly vinyl alcohol (PVA) as
stabilizer, azobisisobutyronitrile (AIBN) as initiator.
 Synthesis of magnetic polymer beads and the magnetic
properties of polymer beads are determined by embedded
magnetic particles. Among these particles, metal oxides are
often preferred over pure metals beacause they are more stable
to oxidation.

12. CONCLUSION
 Suspension polymerization is the most preferred technique in
the polymerization, it gives a complex to other techniques of
polymerization like Emulsion, Bulk, Solution Polymerization.
 Low viscosity, simple polymer isolation and easy thermal
control makes this process of paramount importance.
 While sensitiveness to agitation, post operations and particle
size is less controllable in suspension polymerization.