No abstract

No abstract

Hydrogenation of polybutadienes with from 8 to nearly 100% vinyl content was used to prepare a series of model copolymers of ethylene and butene‐1 with uniform microstructures and narrow molecular weight distributions. They range from readily crystallizable to completely amorphous, depending on the frequency of ethyl side branches (2–50 per 100 skeletal carbons). Melting temperature, secondary transition temperature, density, plateau modulus for the melt, and elastic modulus for the solid were obtained as functions of branch content. The effect of crystallinity on the secondary transition and modulus of the solid is discussed.

A general strategy for fabricating thick, optically flat photopolymer recording media with high dynamic range (M/#) that exhibit low levels of recording-induced Bragg detuning for holographic data storage is presented. In particular, media with M/# values as high as 42 in 1-mm-thick formats are obtained. We believe that these results are the first demonstration of a holographic storage medium with a dynamic range of this magnitude. In addition, we report the holographic recording and recovery of high-capacity (480-kbit) digital data pages in these media, further illustrating their data-storage capabilities.

No abstract