Synthesis and properties of 9,10-dialkoxyanthracenes as fluorescent probes specific of polyolefins and their application to orientation measurement in polyethylene

9,10‐Dialkoxyanthracenes with an even number of carbon atoms n in the aliphatic chain from n = 2 to n = 18 were prepared by reaction of the corresponding bromoalkanes with the sodium salt of dihydroanthraquinone. Ultra‐violet and fluorescence spectra as well as life‐times of the excited state of these different fluorescent probes were determined. Higher terms with n ≥ 8 proved to be valuable to measure the amorphous phase orientation in polyolefins.