Solution properties of phosphonitrilic fluoroelastomers

A series of phosphonitrilic fluoroelastomers which have excellent solvent resistance and low temperature flexibility, and which perform well under a broad range of service conditions, have been developed. The solution properties of one of these polymers were studied more extensively in order to develop suitable quality control procedures and to gain a better understanding of the polymer structure. Solvents for these procedures were established, fractionation procedures were developed, and intrinsic viscosity, osmotic pressure, and light‐scattering measurements were conducted. We found this polymer to have a very broad molecular weight distribution. And, although fractionation by molecular weight was effected, the fractions retained a broad molecular weight distribution. Our data do not indicate significant branching for this polymer. As a result of our studies, we have theorized that a supermolecular structure may be present in this polymer.