Carboxymethylated-, hydroxypropylsulfonated- and quaternized xylan derivative films.

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials

Background:

• Xylan, a natural polysaccharide, possesses a versatile backbone suitable for chemical modification.
• Developing functionalized xylan derivatives is crucial for advanced material applications.
• Understanding the structure-property relationships of modified xylan is essential for tailored material design.

Purpose of the Study:

• To synthesize novel xylan derivatives with carboxymethyl, 2-hydroxypropylsulfonate, and trimethylammonium-2-hydroxypropyl groups.
• To characterize the synthesized materials using advanced analytical techniques.
• To evaluate the impact of different substitutions on the physicochemical and mechanical properties of xylan films.

Main Methods:

• One-step synthesis of substituted xylan under alkaline/water conditions.
• Characterization using Nuclear Magnetic Resonance (NMR), Size Exclusion Chromatography with Multi-Angle Light Scattering (SEC-MALS), Thermogravimetric/Derivative Thermogravimetric/Differential Thermal Analysis (TG/DTG/DTA), Atomic Force Microscopy (AFM).
• Mechanical testing to determine elastic modulus and thermal analysis to assess thermal stability.

Main Results:

• Molar masses ranged from 12.3 to 17.6 kg/mol with low polydispersity (Mw/Mn: 1.27–1.34).
• Elastic modulus decreased with increasing substitution, with pure xylan showing the highest value (7354 MPa) and carboxymethyl/quaternary xylan the lowest (2805 MPa).
• Onset decomposition temperatures for substituted xylans were generally higher than for unmodified xylan, with SX, CQSX, QSX, and CQX showing increased thermal stability.

Conclusions:

• The degree and type of substitution significantly influence the mechanical properties and thermal stability of xylan films.
• The synthesized functionalized xylans offer tunable properties for potential applications in biomaterials and advanced films.
• Surface roughness analysis indicated variations between the top and bottom surfaces of the film specimens.