Abstract
Physical properties of polyenanthamide (nylon 7) and polypelargonamide (nylon 9) which were prepared by the polycondensation of the corresponding ω-amino acids have been investigated.
The melting points (Tm) and glass transition temperature (Tg) of these polyamides were measured by a dilatometric method as 223°C (Tm), 52°C (Tg) for nylon 7 and 210°C (Tm), 46°C (Tg) for nylon 9.
The refractive indices of the isotropic sampless (unstretched filaments) were evaluated as 1.526 (nylon 7) and 1.521 (nylon 9). The maximum degree of birefringences, Δn (max) were 0.058 (nylon 7) and 0.064 (nylon 9).
The films of these polyamides were prepared from the formic acid solution. The crystallinity of film samples were measured by the three different methods (IR, X-ray, and density). The relation between the crystallinities and the specific volumes of these polyamides are expressed by the following equations;
α=7.94-8.33v (nylon 7)
α=8.30-8.47v (nylon 9)
in whichvdenotes the specific volume at 25°C.
