Physico-chemical studies of polyamides I : polyamides having long methylene chain units

Abstract

The polyamides having long methytene chain units have been prepared by the condensation of diamines with dicarboxylic acids, both having long chains of even number methylene units. The effects of the length of the methylene chain units on the melting points, the glass transition paints, the densities and X-ray diffractions of these polyamides were investigated. By plotting the melting points and densities against the amide concentration, both the density and the melting point extrapolated to the zero amide concentration are found to be below the value for polymethylene. The calculated density extrapolated to the zero amide concentratian from the X-ray data is also found to be below the value for polymethylene. The glass transition temperatures lie in the range of 45 to 52℃.