A revised solid-state NMR method to assess the crystallinity of cellulose
Artikel i vetenskaplig tidskrift, 2019

The crystallinity of cellulose has a strong impact on various material properties. Over the years, many methods have become available to estimate the crystallinity. The purpose of this work was to revise existing NMR-based methods and to introduce a complementary NMR method related to the 13C T1 relaxation time. The 13C T1 differs by an order of magnitude for amorphous and crystalline polymers among them cellulose. We have utilized the signal boost of 1H–13C cross polarization and the difference in 13C T1 as a filter to calculate the degree of crystallinity. The evaluation of the method is based on the difference in peak integrals, which is fed into a simple equation. The method was applied to five cellulosic samples of different nature and compared the obtained degree of crystallinity with the degree estimated from deconvoluted X-ray scattering patterns. Furthermore, an attempt has been made to give a basic understanding on the origin of CP enhancement in order to validate various proposed NMR methods. With the recent progress of NMR equipment, the presented method can be automatized and applied to a series of samples using a sample changer.

13 C NMR

MAS

Cross-polarization

13 C T 1

Crystallinity

Cellulose

Författare

T. Sparrman

Umeå universitet

Leo Svenningsson

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Lars Nordstierna Group

Karin Sjövold

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Fysikalisk kemi

Wallenberg Wood Science Center (WWSC)

Lars Nordstierna

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Lars Nordstierna Group

Gunnar Westman

Chalmers, Kemi och kemiteknik, Kemi och biokemi

Diana Bernin

Göteborgs universitet

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk apparatteknik

Cellulose

0969-0239 (ISSN)

Vol. 26 17 8993-9003

Ämneskategorier

Polymerteknologi

Textil-, gummi- och polymermaterial

Sannolikhetsteori och statistik

DOI

10.1007/s10570-019-02718-0

Mer information

Senast uppdaterat

2019-11-12