The crystal structure of polylauryllactam (nylon 12)

Abstract

Abstract The crystal structure of nylon 12 was determined from the X‐ray diffraction patterns of uniaxially oriented specimens. The unit cell is monoclinic (pseudo‐hexagonal) with the following dimensions: a = 4,79 Å, b = 31,9 Å (fiber axis), c = 9,58 Å, β = 120°. There are four monomeric units in the unit cell and the space group is P2 1 / c . The structure presents a distortion of the amide group from the planar chain conformation and it is rather similar to γ‐nylon 6. The hydrogen bond length is about 2,80 Å and the molecular packing is characterized by alternate, “up and down”, highly disordered sheets of parallel chains, linked by hydrogen bonds. The agreement between observed and calculated intensities has been improved by introducing a statistical disorder.