The controlled and pseudo-living ring-opening polymerization of a large ring size lactone, ω-6-hexadecenlactone (6HDL), was achieved for the first time by a dimethyl(salicylaldiminato) aluminum initiator. The obtained poly(ω-6-hexadecenlactone) was functionalized by thiol–ene coupling reaction. By epoxidation of the double bond a poly(6,7-epoxy-ω-hexadecalactone) was formed. The subsequent opening of the epoxide by NaCNBH3 produced a poly(6,7-epoxy-ω-hexadecalactone) with occasional inter and intra ether-type crosslinks. Modifications occurred without any change in the degree of polymerization. The obtained polymeric samples were characterized by NMR, GPC and DSC and X-ray diffraction analysis. The “polyethylene-like” orthorhombic crystal lattice of poly(ω-6-hexadecenlactone) is deformed in the poly(6,7-epoxy-ω-hexadecalactone) and is replaced by a hexagonal packing when the poly(ester) chains are hydroxylated. Furthermore, copolymerization of 6HDL with smaller ε-caprolactone produced random copolymers, with average sequence block lengths of 2, while the sequential addition of 6HDL and ε-caprolactone or rac-lactide allowed the preparation of block-copolymers. The block and random copolymers were also semicrystalline.

Ring-opening polymerization of ω-6-hexadecenlactone by a salicylaldiminato aluminum complex: a route to semicrystalline and functional poly(ester)s

PAPPALARDO D.
2015-01-01

Abstract

The controlled and pseudo-living ring-opening polymerization of a large ring size lactone, ω-6-hexadecenlactone (6HDL), was achieved for the first time by a dimethyl(salicylaldiminato) aluminum initiator. The obtained poly(ω-6-hexadecenlactone) was functionalized by thiol–ene coupling reaction. By epoxidation of the double bond a poly(6,7-epoxy-ω-hexadecalactone) was formed. The subsequent opening of the epoxide by NaCNBH3 produced a poly(6,7-epoxy-ω-hexadecalactone) with occasional inter and intra ether-type crosslinks. Modifications occurred without any change in the degree of polymerization. The obtained polymeric samples were characterized by NMR, GPC and DSC and X-ray diffraction analysis. The “polyethylene-like” orthorhombic crystal lattice of poly(ω-6-hexadecenlactone) is deformed in the poly(6,7-epoxy-ω-hexadecalactone) and is replaced by a hexagonal packing when the poly(ester) chains are hydroxylated. Furthermore, copolymerization of 6HDL with smaller ε-caprolactone produced random copolymers, with average sequence block lengths of 2, while the sequential addition of 6HDL and ε-caprolactone or rac-lactide allowed the preparation of block-copolymers. The block and random copolymers were also semicrystalline.
2015
macrolactone; aluminum; funtional polymer
File in questo prodotto:
File Dimensione Formato  
PolymChem_2015.pdf

non disponibili

Licenza: Non specificato
Dimensione 855.3 kB
Formato Adobe PDF
855.3 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/20.500.12070/6020
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 35
  • ???jsp.display-item.citation.isi??? 35
social impact