Rheology of Polyhydroxyalkanoate Solutions

Abstract

The rheology of solutions of polyhydroxyalkanoates in chloroform and dichloromethane was studied. The dynamic viscosity of solutions depended on type of solvent and PHA. The polymer solutions with increase of temperature behave as Newtonian fluids. Dynamic viscosity was increasing with the concentration of polymer in solution, regardless of the solvent. Solutions of PHAs in descending order of magnitude of dynamic viscosity can be positioned in the following order: P(3HB) – P(3HB-3HV) – P(3GB-3HH) – P(3HB-4HB). The magnitude of the dynamic viscosity of solutions based on chloroform in 3-3,5 times higher than that of solutions based on dichloromethane at identical concentration and temperature. The obtained values of dynamic viscosity have demonstrated the dependence of rheological parameter on the chemical composition of the polymer, and the characteristics of solvent (composition, temperature, and concentration)

Keywords

• polyhydroxyalkanoates
• dynamic viscosity
• chloroform
• dichloromethane