Prevailingly isotactic poly(propy1ene) samples were prepared with a homogeneous catalytic system based on a bis(imin0)pyridyl Fe(I1) derivative and methyl~uminoxane. The polymer microstructure is in agreement with Bernoutlian statistics of dyad formation, implicating a "chain-end mechanism of steric control. The latter is operative even at polymerization temperatures as high as +50"C. NMR analysis of polymer end groups indicates that chain growth proceeds via 2,l monomer insertion. The last two findings are unprecedented for isotactic-specific polymerization of propene and are reasonably related to each other.

Isotactic-specific polymerization of propene with an iron-based catalyst: polymer end groups and regiochemistry of propagation

PAPPALARDO D.
1998

Abstract

Prevailingly isotactic poly(propy1ene) samples were prepared with a homogeneous catalytic system based on a bis(imin0)pyridyl Fe(I1) derivative and methyl~uminoxane. The polymer microstructure is in agreement with Bernoutlian statistics of dyad formation, implicating a "chain-end mechanism of steric control. The latter is operative even at polymerization temperatures as high as +50"C. NMR analysis of polymer end groups indicates that chain growth proceeds via 2,l monomer insertion. The last two findings are unprecedented for isotactic-specific polymerization of propene and are reasonably related to each other.
isotactic polypropilene; iron catalysts; polymer end groups; mechanism
File in questo prodotto:
File Dimensione Formato  
IsoPP_Fe_MacrRapCommun_1998.pdf

non disponibili

Licenza: Non specificato
Dimensione 528.58 kB
Formato Adobe PDF
528.58 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12070/5054
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 82
  • ???jsp.display-item.citation.isi??? 80
social impact