THERMAL BEHAVIOR OF CELLULOSE NANOCRYSTAL (CNC) FILMS (PPT)

摘要

PLIC is a new method for CTE determination of transparent, semi-opaque, or semitransparent films where contact forces are important and/or anisotropic and heterogeneous CTE plays a role. PLIC is ideally suited to CTE determination in CNC films as they show well-defined native speckle patterns and tend to heterogeneity and anisotropy. Random CNC films show isotropic CTE of-25 ppm/°K. Oriented films show anisotropy dependent on degree of orientation with an orientation parameter of 0.8 giving-8.5 ppm/°K in the same direction as and-160 ppm/°K orthogonal to director. Extrapolation to S=1 gives-7.8 ppm/°K with director, similar to XRD based CTE, but a high value of-210 ppm/°K, orthogonal to director, indicating intercrystal effects. Modeling suggests that intercrystal "frictional" sliding plays a role in CTE and may explain the high orthogonal value.