Haze and light scattering of transparent crystallized cyclo olefin polymer

We investigated the haze and light scattering in a crystallized cyclo olefin polymer film of syndiotactic hydrogenated poly(endo-dicyclopentadiene) (SH-DCP), consisting of small spherulites with radially arranged lamellar stacks. To clarify the relationship between haze and light scattering, haze was classified as external and internal. The cold-crystallized SH-DCP was highly transparent with low levels of external and internal haze (0.8%). The low external haze was due to the absence of significant surface roughness, as confirmed by a 3D optical profilometer and an ultraviolet-visible spectrometer. Internal haze was related to the integrated light scattering intensity, Q , in the Vv (parallel-polarized) mode. Q was classified as int- Q in the initial melt state and cry- Q , which was enhanced by crystallization and obtained by analyzing the time variation of Q during melt crystallization. Analyzing the light scattering intensity profiles obtained from the four-leaf clover pattern in the Hv (cross-polarized) mode, and the cry- Q in the Vv and Hv modes, revealed that the low internal haze was due to the small size of the spherulites, the small refractive index difference within each spherulite, and the low arrangement of the lamellar stacks. Due to the low levels of external and internal haze, the transmitted and reflected views of text using the cold-crystallized film were clear.