In this paper, the synthesis of isotactic polypropylenes (i-PP) modified with [BOND]OH groups in sides (iPP-OH), by combination of polyinsertion ansa-metallocene catalysis and ring opening of propene oxide (PO), is described. i-PP sequences interrupted by isolated ethylene/p-methylstyrene units forms the backbone. This enchainment is obtained by controlled copolymerization of propene with ethylene and p-methylstyrene comonomers in the presence of rac-ethylenebis(1-indenyl)zirconiumdichloride/methylalumoxane system. The metallation reaction of the p-methyl group with sec-BuLi generates an anionic center that can be reacted with PO. The iPP-OH is the result of the monoaddition reaction of PO followed by hydrolysis with acidified methanol. By changing experimental conditions in the backbone synthesis, a tuned number of the functionalizable sites as well as polypropylene sequence lengths can be obtained. As a consequence, iPP samples with a different number of [BOND]OH groups for the backbone can be synthesized after the PO monoaddition reaction.

Synthesis of hydrophilic isotactic polypropylenes promoted by metallocene catalysts

CAPORASO, Lucia;OLIVA, Leone
2006

Abstract

In this paper, the synthesis of isotactic polypropylenes (i-PP) modified with [BOND]OH groups in sides (iPP-OH), by combination of polyinsertion ansa-metallocene catalysis and ring opening of propene oxide (PO), is described. i-PP sequences interrupted by isolated ethylene/p-methylstyrene units forms the backbone. This enchainment is obtained by controlled copolymerization of propene with ethylene and p-methylstyrene comonomers in the presence of rac-ethylenebis(1-indenyl)zirconiumdichloride/methylalumoxane system. The metallation reaction of the p-methyl group with sec-BuLi generates an anionic center that can be reacted with PO. The iPP-OH is the result of the monoaddition reaction of PO followed by hydrolysis with acidified methanol. By changing experimental conditions in the backbone synthesis, a tuned number of the functionalizable sites as well as polypropylene sequence lengths can be obtained. As a consequence, iPP samples with a different number of [BOND]OH groups for the backbone can be synthesized after the PO monoaddition reaction.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

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/11386/1513597
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 4
  • ???jsp.display-item.citation.isi??? 4
social impact