Содержание
- 2. 7.1 Introduction Presence of counterions (= gegenions) Influence of counterions Solvation effect more complex than free
- 3. 7.1 Introduction
- 4. TABLE 7.1. Commercially Important Polymers Prepared by Ionic Polymerization Polymer or Copolymer Cationica Polyisobutylene and polybuteneb
- 5. 7.2.1 Cationic initiators 7.2.2 Mechanism, kinetics, and reactivity in cationic polymerization 7.2.3 Stereochemistry of cationic polymerization
- 6. 7.2.1 Cationic Initiators The propagating species : carbocation Coinitiator
- 7. (7.5) (7.6) (7.7) (7.8) Other initiators 7.2.1 Cationic Initiators
- 8. Other initiators 7.2.1 Cationic Initiators
- 9. 7.2.2 Mechanism, Kinetics, and Reactivity in Cationic Polymerization Carbocationic Initiation. addition of the electrophilic species –
- 10. 7.2.2 Mechanism, Kinetics, and Reactivity in Cationic Polymerization Carbocationic Initiation.
- 11. B. Propagation Step 7.2.2 Mechanism, Kinetics, and Reactivity in Cationic Polymerization
- 12. C. Influences polymerization rate
- 13. D. Chain transfer reaction
- 14. D. Chain transfer reaction
- 15. E. Termination reaction
- 16. F. Proton trap
- 17. G. Telechelic Polymer
- 18. H. Pseudocationic Polymerization
- 19. I. To prepare living polymers under cationic conditions.
- 20. I. To prepare living polymers under cationic conditions.
- 21. J. Kinetics
- 23. Substituting for in , one obtains In the absence of any chain transfer, (the kinetic chain
- 24. K. Difference between free radical and cationic processes.
- 25. L. Nonconjugation diene – Cationic cyclopolymerization 7.2.2 Mechanism, Kinetics, and Reactivity in Cationic Polymerization
- 26. Cationic Polymerization lead to stereoregular structures. ex) vinyl ether α - methylstyrene Vinyl ether observation resulting
- 27. EX) t-butyl vinyl ether forms isotactic polymer in nonpolar solvents. forms mainly syndiotactic polymer in polar
- 28. In polar solvents both ions 1) be strongly solvated 2) the chain end – exist as
- 29. (7.29) (7.30) Models proposed for vinyl ether polymerization
- 31. 7.2.4 Cationic Copolymerization A. Copolymerization equation - the situation is complication by counterion effects. B. Reactivity
- 32. TABLE 7.3. Representative Cationic Reactivity Rations (r)a Monomer 1 Monomer 2 Coinitiatorb Solventb Temperature (oC) r1
- 33. 7.2.5 Isomerization in Cationic Polymerization (7.34) (7.35)
- 34. 7.3 Anionic Polymerization 7.3.1 Anionic initiators 7.3.2 Mechanism, kinetics, and reactivity in anionic polymerization 7.3.3 Stereochemistry
- 35. (7.36) Propagating chain - carbanion Examples – nitro, cyano, carboxyl, vinyl, and phenyl. Monomers having substituent
- 36. The strength of the base necessary to initiate polymerization depends in large measure on monomer structure
- 37. Two basic types that react by addition of a negative ion that undergo electron transfer. ①
- 38. 7.3.1 Anionic Initiators
- 39. 7.3.2 Mechanism, kinetics, and reactivity in anionic polymerization A. Mechanism을 변화시킬 수 있는 요인 a. solvent
- 40. b. Type of cation (counterion) c. Temperature B. The rate of initiation - initiator 와 monomer의
- 41. D. Kinetic 7.3.2 Mechanism, kinetics, and reactivity in anionic polymerization Because the second step is slow
- 42. Substituting in Rp we obtain The average kinetic chain length, is expressed as Assuming a steady
- 43. E. Other types of transfer reactions 7.3.2 Mechanism, kinetics, and reactivity in anionic polymerization
- 44. 7.3.2 Mechanism, kinetics, and reactivity in anionic polymerization
- 45. 7.3.2 Mechanism, kinetics, and reactivity in anionic polymerization G. Important factor in propagation rate. a. Association
- 46. 7.3.2 Mechanism, kinetics, and reactivity in anionic polymerization G. Important factor in propagation rate.
- 47. 7.3.3 Stereochemistry of anionic polymerization A. Stereochemical of nondiene vinyl monomer With soluble anionic initiators (homogeneous
- 48. 7.3.3 Stereochemistry of anionic polymerization A. Stereochemical of nondiene vinyl monomer
- 49. 7.3.3 Stereochemistry of anionic polymerization A. Stereochemical of nondiene vinyl monomer Effect of solvent
- 50. B. Stereochemical of Dienes 7.3.3 Stereochemistry of anionic polymerization catalyst, solvent의 영향 isoprene 1,3-butadiene Li-based initiator/nonpolar
- 51. formation of cis-polyisoprene – lithium’s ability forming a six-membered ring transition state – “lock” the isoprene
- 52. 7.3.4 Anionic Copolymerization ④ contrasts between homogeneous and heterogeneous polymerization systems.
- 54. 7.3.4 Anionic Copolymerization formation of block copolymers by the living polymer method.
- 55. ABA triblock polymers – Greatest commercial success ex) styrene-butadiene-styrene star-block (radial) – much lower melt viscosities,
- 56. 7.4 Group Transfer Polymerization (GTP) (In the 1980s a new method for polymerizing acrylic-type monomers) GTP의
- 58. 7.4 Group Transfer Polymerization (GTP) 두 개의 작용기를 갖는 개시제 사용 사슬의 양끝에서 성장
- 59. 7.4 Group Transfer Polymerization (GTP)
- 60. 7.4 Group Transfer Polymerization (GTP)
- 62. Скачать презентацию