Dielectric properties of poly(4-methylphenylisocyanate) and poly(4-methoxyphenylisocyanate) in solution

✍ Scribed by L. Lecomte; E. Marchal

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 430 KB
• Volume: 12
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(76)90086-0

✦ Synopsis

In the range 200 Hz-2 MHz, the dielectric behaviour of two polyarylisocyanates depends on the solvent. In certain solvents, such as toluene, there is only one high frequency absorption for poly(4-methylphenylisocyanate) and it is independent of molecular weight. Its character corresponds to chains having a low kinetic flexibility. In other solvents, this polymer, as well as poly(4-methoxyphenylisocyanate), shows two regions of dielectric absorption. The low frequency relaxation is molecular weight dependent: a polarization due to solvent polymer interactions occurs along the main chain. Despite its solvent-dependence, the total dipole moment of these polyarylisoeyanates which behave like coils is much lower than that of polyalkylisoeyanates, which are known to be rod-like.