SYNTHESIS AND CHARACTERIZATION OF TRIMETHYLSILYLCELLULOSE IN SOLUTION

Five samples of cellulose, with different polymerization degrees, were used to obtain corresponding trimethylsilylcellulose derivatives by r eaction with trimethylchlorsilan. The trimethylsilylcellulose (TMSC) s amples 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, indi cating great stiffness of the macromolecules in solution. Also, the te mperature dependence of both the limiting viscosity number and M-H-S c oefficients 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 temp erature. The GPC studies indicate a relatively high polydispersity of the studied samples; the polydispersity index being situated between t wo and three.