Abstract
The β-form crystal structure of the poly (L-glutamic acid) fibers, spun from concentrated poly (L-sodium glutamate) (PSLG) aqueous solution with H3PO4 coagulant, were studied. Well-oriented clear X-ray diffraction patterns were obtained, and were led to assign the following orthorhombic unit cell;
a=9.26 Å (direction of hydrogen bond)
b=7.73 Å (direction of side chain)
c=6.90 Å (fiber axis)
The result of infra-red spectroscopy indicates that the β-crystal structure constituted an anti-parallel, slightly pleated sheets. The calculated and observed densities were 1.73g/cc and 1.47g/cc, respectively.
Powder-like precipitate of PGA, aggregates of minute crystals was obtained from PSLG dilute aqueous solution. The crystal structure well agreed with the β-form of the PGA fiber.
