| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1385857 | Carbohydrate Polymers | 2014 | 8 Pages |
•Three ion-exchanging groups were introduced into xylan in one step.•The properties were compared with double and single substituted xylan.•Films were prepared from the derivatives and tested.•Roughness values of film top sides were bigger than on bottom.
Under alkaline/water conditions carboxymethyl, 2-hydroxypropylsulfonate and trimethylammonium-2-hydroxypropyl groups were introduced into xylan in one step with the goal to prepare film specimens. The materials were characterized by NMR, SEC-MALS, TG/DTG/DTA, AFM and mechanical testing. The properties of triple, double and mono-substituted materials were compared. The numerical molar masses of the specimens were from 12.3 to 17.6 kg/mol with Mw/Mn from 1.27 to 1.34. The elastic modulus values are decreasing in order: xylan (X; 7354 MPa) > carboxymethyl xylan (CX; 6090 MPa) > 2-hydroxypropylsulfonate xylan (SX; 6000 MPa) > carboxymethyl/2-hydroxypropylsulfonate xylan (CSX; 4490 MPa) > quaternized xylan (QX; 3600 MPa) > carboxymethyl/quaternary/2-hydroxypropylsulfonate xylan (CQSX; 3380 MPa) > carboxymethyl/quaternary xylan (CQX; 2805 MPa). The onset temperatures of SX (214 °C), CQSX (212 °C), QSX (211 °C) and CQX (207 °C) were higher than for X (205 °C). The roughness values of the film surfaces (3.634 – 18.667 nm) are higher on top than on the bottom of the specimen.
