Synthesis and characterization of trimethylsilylcellulose in solution

Five samples of cellulose, with different polymerization degrees, were used to obtain corresponding trimethylsilylcellulose derivatives by reaction with trimethylchlorsilan. The trimethylsilylcellulose (TMSC) samples were characterized in solution by osmometry, viscometry and gel permeation chromatography. The Mark-Houwink-Sakurada (M-H-S) equation coefficients were determined in chloroform, 1,1,1-trichloroethane and o-xylene, in all cases the exponent "a" being higher than 1.0, indicating great stiffness of the macromolecules in solution. Also, the temperature dependence of both the limiting viscosity number and M-H-S coefficients for TMSC in o-xylene were studied. The exponent from M-H-S equation is also higher than 1.0 and increases linearly with the temperature. The GPC studies indicate a relatively high polydispersity of the studied samples; the polydispersity index being situated between two and three.