METHOD OF DETERMINING MOLECULAR-MASS DISTRIBUTION OF POLYMER MOLECULES Russian patent published in 1998 - IPC

FIELD: polymer materials. SUBSTANCE: sample is simultaneously affected by punch and temperature raised with constant rate within the range from polymer vitrification temperature to temperature at which polymer transfers into high-elasticity state. Displacement of punch is determined for the entire series of temperature values and elasticity modulus values E corresponding to those temperatures. In addition, E=f(T) function is plotted and segment in the curve is found corresponding to high-elasticity plateau. Elasticity modulus value E₀ for this segment is extrapolated by straight line, and values of elasticity modulus for other segments are decreased by E₀, after which derivative of temperature dependence with respect to quadratic root of all values obtained upon extrapolation procedure is calculated, which is chosen as a parameter to judge about molecular-mass distribution of polymer molecules. EFFECT: improved estimation procedure. 1 dwg, 1 tbl