title: Solid-state NMR characterization of cross-linking in EPDM/PP blends from 1H-13C polarization transfer dynamics.
abstract: A novel approach for solid-state NMR characterization of cross-linking in polymer blends from the analysis of (1)H-(13)C polarization transfer dynamics is introduced. It extends the model of residual dipolar couplings under permanent cross-linking, typically used to describe (1)H transverse relaxation techniques, by considering a more realistic distribution of the order parameter along a polymer chain in rubbers. Based on a systematic numerical analysis, the extended model was shown to accurately reproduce all the characteristic features of the cross-polarization curves measured on such materials. This is particularly important for investigating blends of great technological potential, like thermoplastic elastomers, where (13)C high-resolution techniques, such as CP-MAS, are indispensable to selectively investigate structural and dynamical properties of the desired component. The validity of the new approach was demonstrated using the example of the CP build-up curves measured on a well resolved EPDM resonance line in a series of EPDM/PP blends.
authors.affiliation: Department of Physics, Martin-Luther University, 06110 Halle, Germany.
authors.forename: Mihaela
authors.initials: M
authors.lastname: Aluas
authors.forename: Claudiu
authors.initials: C
authors.lastname: Filip
mesh_terms: D000465:Algorithms; D002247:Carbon Isotopes; D045424:Complex Mixtures / Q000032:analysis / Q000737:chemistry; D003198:Computer Simulation; D003432:Cross-Linking Reagents / Q000032:analysis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D011126:Polypropylenes / Q000032:analysis / Q000737:chemistry*; D011208:Powders; D011522:Protons; D012408:Rubber / Q000032:analysis* / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D045424:Complex Mixtures; D003432:Cross-Linking Reagents; D011126:Polypropylenes; D011208:Powders; D011522:Protons; D012408:Rubber