Studies on the macromolecular structure of polymers through measurements of rheological properties
Polimery 1997, No 5, 321
The literature has been reviewed on the use of rheological measurement data for determining the structure parameters of macromolecules such as the average molecular weight (Mx) and long chain branching (LCB) of macromolecules. Authors' experimental data concerning polydimethyl siloxane (PDMS) and polypropylene have been described. The weight-average molecular weight was determined by the use of the extended Bueche relationship, η0= f(Мx, q). The branched and linear polymers were distinguished in terms of the exponent by which defines the slope of the relatio Δφη0 = f(ω η0). As confirmed for PDMS, b1 =0.76 for linear polymers, whereas for branched polymers, b1 < 0.76. The lower the degree of branching G, the smaller the exponent b1. Earlier, the relationship b1 = f(G) was suggested to be linear.