mechanism of polymerization-1)chain growth polymerization 2)step growth polymerization

1. MECHANISM OF POLYMERIZATION
Guided By Presented By
Mr.Nasir Ahmed Sumeet Kumar Jha
Dr.Ashish Asatkar M.Sc.(Chemistry)
Mrs.ChitraKiran Patel 3rd Semester
GOVT.GUNDADHUR
P.G.COLLEGE,KONDAGAON(C.G.)

2. Contents
 INTRODUCTION
 MODE OF POLYMERIZATION
 DIFFERENCE BETWEEN CHAIN GROWTH AND STEP
GROWTH POLYMERIZATION
 STEREOCHEMISTRY OF POLYMERIZATION
 ACTIVE INTERMRDIATES
 MECHANISM OF CHAIN GROWTH POLYEMERIZATION
 MECHANISM OF STEP GROWTH POLYMERIZATION
 CONCLUSION

3. INTRODUCTION
• The process by which the monomer molecules are linked to
form a big polymer molecule is called Polymerization.
• Polymerization is a process of a bonding monomer or
“single unit” together through a variety of reaction
mechanisms to form longer chains named polymer.

4. mode OF POLYMERIZATION
There are two modes of Polymerization:-
 Chain Growth Polymerization
 Step Growth Polymerization

5. CHAIN GROWTH POLYMERIZATION
• Chain growth polymerization is the process of
repeated addition of monomers that possess double or
triple bonds to form polymers.
• In which the high molecular weight polymer is formed.
• Also the polymer yield gradually increases with time.
• It is also known as addition polymerization.

6. EXAMPLE OF CHAIN GROWTH
POLYMERIZATION

7. Step Growth Polymerization
• Step-growth polymerization refers to a type
of polymerization mechanism in which bi-functional or
multifunctional monomers react to form first dimers, then
trimers, longer oligomers and eventually long chain
polymers.
• It is also known as condensation polymerization.
• Condensation polymerization is a process that involves
repeated condensation reactions between two different bi-
functional or tri-functional monomeres.
• In condensation polymerization some product such as
H2O,NH3 etc. are released.

8. Step Growth Polymerization

9. EXAMPLE OF STEP GROWTH
POLYMERIZATION

10. DIFFERENCE BETWEEN CHAIN GROWTH
AND STEP GROWTH POLYMERIZATION

11. STEREOCHEMISTRY OF
POLYMERIZATION

12. ACTIVE INTERMRDIATES

13. MECHANISM OF CHAIN GROWTH
POLYEMERIZATION
There are three types of chain growth
polymerization:-
 Free radical polymerization
 Cationic polymerization
 Anionic polymerization

14. MECHANISM OF FREE RaDICAL
POLYMERIZATION

15. FREE RaDICAL POLYMERIZATION

16. Example of FREE RaDICAL
POLYMERIZATION

17. MECHANISM OF Cationic
polymerization

18. MECHANISM OF Cationic
polymerization

19. EXAMPLE OF Cationic
polymerization

20. MECHANISM OF anionic
polymerization

21. MECHANISM OF anionic
polymerization

22. EXAMPLE OF anionic
polymerization

23. MECHANISM OF STEP GROWTH
POLYEMERIZATION

24. MECHANISM OF STEP GROWTH
POLYEMERIZATION

25. MECHANISM OF STEP GROWTH
POLYEMERIZATION
1) M + M° M-M°
M-M° + M M-M°-M
M-M°-M + M M-M°-M-M°
Thus constuct (M-M°)n
2) M + M° M-M°
(M-M°) + (M-M°) M-M°-M-M°
(M-M°) + n(M-M°) (M-M°)n
Thus constuct (M-M°)n
Where M and M° are monomers

27. CONCLUSION
• Two or more monomers are combined to form polymers.
• In chain growth polymerization double or triple bond of
two or more monomers are breaks down to form chain of
polymer.
• Chain growth polymerization can be three types such as –
by free redical or by cation and anion.
• In step growth polymerization bi-functional or tri-
functional monomers are combined to form chain and
some simple molecule (H2O,NH3 etc) release during
polymerization.

28. REFERENCE
TEXT book of “Advanced Physical Chemistry” by
G.N.Gurtu & Amit Gurtu