Shortly after processing, Polyethylene/Polypropylene (PE/PP) multilayer films demonstrate an increase in tensile modulus and other mechanical properties when the individual layer thickness is below 0.5 μm. Subsequent annealing at 60 °C for 16 h brings the properties of all other samples to similar values. WAXD characterization of the layered films identified a prevalence of mesophase in the thicker PP layers. In samples with increased layer numerosity or subjected to annealing, WAXD detected its conversion to α crystalline phase that correlates with improved mechanical properties. SSNMR and DSC detailed the defective nature of α iPP crystallites. Comonomers, detected by NMR in the commercial polymers used for the films, are the source of "tunable disorder" that dictates the formation of the PP mesophase and the low temperature of conversion to the mechanically stronger defective α phase. Soft intrafilm layer interfaces instead enable nucleation and localized polymer chain rearrangement even without annealing

Mauri, M., Ponting, M., Causin, V., Simonutti, R., Pisciotti, F. (2018). Morphological reorganization and mechanical enhancement in multilayered polyethylene/polypropylene films by layer multiplication or mild annealing. JOURNAL OF POLYMER SCIENCE. PART B, POLYMER PHYSICS, 56(6), 520-531 [10.1002/polb.24561].

Morphological reorganization and mechanical enhancement in multilayered polyethylene/polypropylene films by layer multiplication or mild annealing

Mauri, Michele
Primo
;
Simonutti, Roberto
Penultimo
;
2018

Abstract

Shortly after processing, Polyethylene/Polypropylene (PE/PP) multilayer films demonstrate an increase in tensile modulus and other mechanical properties when the individual layer thickness is below 0.5 μm. Subsequent annealing at 60 °C for 16 h brings the properties of all other samples to similar values. WAXD characterization of the layered films identified a prevalence of mesophase in the thicker PP layers. In samples with increased layer numerosity or subjected to annealing, WAXD detected its conversion to α crystalline phase that correlates with improved mechanical properties. SSNMR and DSC detailed the defective nature of α iPP crystallites. Comonomers, detected by NMR in the commercial polymers used for the films, are the source of "tunable disorder" that dictates the formation of the PP mesophase and the low temperature of conversion to the mechanically stronger defective α phase. Soft intrafilm layer interfaces instead enable nucleation and localized polymer chain rearrangement even without annealing
Articolo in rivista - Articolo scientifico
confinement; mechanical properties; mesophases; multilayer films; nanostructures; NMR spectroscopy; polymer processing; polymers; polypropylene crystallinity; polypropylene mesophases; X-ray Diffraction;
Confinement; Mechanical properties; Mesophases; Multilayer films; Nanostructures; NMR spectroscopy; Polymer processing; Polymers; Polypropylene crystallinity; Polypropylene mesophases; X-ray Diffraction; Condensed Matter Physics; Physical and Theoretical Chemistry; Polymers and Plastics; Materials Chemistry
English
15-dic-2017
2018
56
6
520
531
none
Mauri, M., Ponting, M., Causin, V., Simonutti, R., Pisciotti, F. (2018). Morphological reorganization and mechanical enhancement in multilayered polyethylene/polypropylene films by layer multiplication or mild annealing. JOURNAL OF POLYMER SCIENCE. PART B, POLYMER PHYSICS, 56(6), 520-531 [10.1002/polb.24561].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/178824
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