Preparation and Crystal Structure Analysis of High-Strength Film Derived from Nigeran Ester Derivatives

Nigeran (α-1,3-alt-α-1,4-glucan) is a linear glucan with alternating α-1,3- and α-1,4-glycosidic linkages. It extracted from the cell walls of certain species in genera Aspergillus Penicillium. can be esterified used as film, but its strength only approximately 4–25 MPa. However, present study, high-strength nigeran ester films tensile strengths 100 MPa were successfully prepared by thermally stretching annealing melt-quenched films. Two-dimensional wide-angle X-ray diffraction (2D-WAXD) analysis revealed that highly oriented butyrate (NGBu), valerate (NGVa), hexanoate (NGHx) studied herein had two-fold helix symmetry along molecular axis. Assuming crystal systems to orthorhombic, unit lattice each was calculated NGBu (a=28.6Å, b=9.07Å, c=16.5Å), NGVa (a=31.5Å, c=16.2Å), NGHx (a=36.7Å, c=16.2Å). In parameters, a-axis extended number carbons increased.