| Full text | |
| Author(s): |
Perez, Martha Gonzales
;
Lima, Aline Pinde
;
Moraes, Tiago Bueno
;
Chaves, Erica Gervasoni
;
da Silva Ruiz, Naira Machado
;
dos Santos Teixeira, Sylvia Correa
;
Honorato, Hercilio de Angeli
;
Cabral de Menezes, Sonia Maria
;
DeAzevedo, Eduardo Ribeiro
Total Authors: 9
|
| Document type: | Journal article |
| Source: | Polymer Degradation and Stability; v. 202, p. 10-pg., 2022-06-05. |
| Abstract | |
In this article H-1 Time Domain Nuclear Magnetic Resonance (TD-NMR) techniques were used to evaluate changes in the microstructure and chain mobility of polyamide 11 (PA11) induced by the exposure to a commercial H2S scavenger. Dipolar based NMR pulse sequences such as H-1 mixed Magic Sandwich Echo (mixed-MSE), H-1 Dipolar Filtered Magic Sandwich Echo (DF-MSE) and 1H Double Quantum time domain NMR (DQ-TDNMR), were applied. These methods provided information about changes in the segmental mobility, phase composition and chain crosslinking and entanglement in PA11. Mixed-MSE and DF-MSE results indicated that the contact with the H2S Scavenger does not substantially change the crystallinity of PA11, but induces significant decrease on the chain mobility of its amorphous phase. DQ-TDNMR results obtained in the melt state of PA11 suggest that such decrease occurs due to the formation of crosslinks between PA11 chains induced by the H2S scavenger. In summary, while a simple mixed-MSE experiment may provide clear evidences about the polymer molecular integrity, more sophisticated methods such DF-MSE and DQ-TDNMR can be used to shed light on the nature of the degradation process. Because PA11 is one of the prime polymers used as barrier layer on flexible oil production pipelines, our results may be important for understating the set of conditions and parameters that contribute to its integrity (AU) | |
| FAPESP's process: | 17/24465-3 - NMR methods for plant cell wall characterization: development and applications to second generation biofuel technologies |
| Grantee: | Eduardo Ribeiro de Azevedo |
| Support Opportunities: | Program for Research on Bioenergy (BIOEN) - Regular Program Grants |
| FAPESP's process: | 09/18354-8 - Dynamics and structure of polymer systems as studied by nuclear magnetic resonance |
| Grantee: | Eduardo Ribeiro de Azevedo |
| Support Opportunities: | Regular Research Grants |