Macromolecular structure and film properties of enzymatically-engineered high molar mass dextrans

作者：Faucard Pauline; Grimaud Florent; Lourdin Denis^*; Maigret Jean Eudes; Moulis Claire; Remaud Simeon Magali; Putaux Jean Luc; Potocki Veronese Gabrielle; Rolland Sabate Agnes^*

来源：Carbohydrate Polymers, 2018, 181: 337-344.

DOI：10.1016/j.carbpol.2017.10.065

• Dextrans
• Sucrose-active enzymes
• Asymmetrical flow field-flow fractionation
• Thermal properties
• Hygromechanical properties

New alpha(1 -> 2) or alpha(1 -> 3) branched dextrans with high molar masses and controlled architecture were synthesized using a dextransucrase and branching sucrases. Their molecular structure, solubility, conformation, film-forming ability, as well as their thermal and mechanical properties were determined. These new dextrans present structures with low densities from 9,500 to 14,000 g m(-3) in H2O/DMSO medium, their molar mass, size and dispersity increase with increasing branching degree (weight-average molar mass up to 10(9) g mol(-1) and radius of gyration around 500 nm). Dextrans exhibit a glass transition between 40.5 and 63.2 degrees C for water content varying from 12.2 to 14.1%. The effect of branching is mainly observed on the ability of dextran to crystallize. They have a good film-forming ability with a storage modulus which varies from 2 to 4 GPa within a relative humidity range of 10-50%.

• 出版日期2018-2-1