Copolymers with formaldehyde and selenoformaldehyde units

SynopsisThe molecular weight distribution of a series of polyisobutylenes was determined using osmotic pressure measurements, gel permeation chromatography, and intrinsic viscosity. All of the polymers except for one, a blend of the highest and lowest molecular weight constituents, had similar moderate molecular weight distributions. The "extended chain length" method of calibrating the gel permeation chromatograph for polyisobutylenes was found to be effective. Steady state and transient shear stresses and normal stresses were measured on 5% decalin solutions of these polymers. The zero shear viscosity increased with the 3.3 power of molecular weight, and the zero shear normal stress coefficient (all -az2)/r2 varied with the 7.5 power. Relative elastic memory as measured by (UII -U Z~) / U I Z or stress relaxation increased with increasing molecular weight (and at constant number-or weight-average molecular weight) with breadth of distribution. Stress overshoot also correlated with this tendency.

show abstract

Copolymers with formaldehyde and selenoformaldehyde units

Cited by 22 publications

References 6 publications

Selenium‐ and tellurium‐containing organic polymers

Selenium‐ and tellurium‐containing organic polymers

Selenium and tellurium heterocycles

Molecular weight distribution and rheological properties of polyisobutylene solutions

Contact Info

Product

Resources

About