Polymer Rheological Parameters Fitting And The Generation Of Master Curves

Rheology helps to understand the polymer's good processing properties, make the proper processing conditions and fabricate the best goods. Rheology is the theoretic foundation to get the desired goods through the rheological parameters.The main work of this paper is as following about the polymer rheological parameters fitting and master curve:(1) Calculate the parameters (B, Tb, τ~* and n) of about one hundred kinds of materials by data fitting. Polymers with similar structure and different molecular weight have the same dependence on temperature. Get the master curve on the basis of time-temperature superposition, and master curves of ABS, SAN, PS, PP, HIPS, HDPE, POM are good from the experiment results(2) Draw the master curve η-MFI - ηIMFI. Get the material's MFI at different temperature and loading from experiment for master curve. The master curve has nothing to do with temperature and grades. Although there is error in calculation from master curve, the curve is ideal for engineering calculation. It overcome the fault that the zero viscosity is difficult to get for (η0 ) master curve.(3) Get dynamic data at different temperature and frequency with ARES which is strain-controlled rotational rheometer. Respectively extract the horizontal and vertical activation energy from loss tangent vs. frequency and loss tangent vs. complex modulus data, calculate the horizontal and vertical shift factors, then there is a good master curve not only for dynamic data but also for steady data.(4) The discrete relaxation time spectrum is calculated from the store modulus and the loss modulus which are got from the dynamic frequency test. In the calculating process the results are get from different relaxation numbers of the Maxwell unit, relaxation time ranges, temperatures and different materials.