Hydrophobically Modified Scleroglucans via Acyl Chlorides with Different Alkyl Chain Lengths

Scleroglucan (Sclg) polysaccharide was reacted, in an aqueous medium, with different acyl chlorides including stearoyl chloride (StCl, C18), decanoyl chloride (DecCl, C10) and hexanoyl chloride (HexCl, C6) to prepare various hydrophobically modified Sclgs (HM-Sclg). Dilute solution viscometry and drop weight method revealed the role of the alkyl chain length of the modifying molecule on the conformation, aqueous solution viscosity and surface tension of Sclg. The results showed that DecCl-Sclg has the highest intrinsic viscosity, while StCl-Sclg possessed the lowest surface tension (the highest hydrophobicity) among the HM-Sclgs. Finally, we suggest that aqueous solution properties of Sclg can be controlled by rational designing of the length of the polysaccharide alkyl side chain.