Polyurethanes composed of 2,4-toluene diisocyanate (TDI), poly(butylene adipate) diols (PBA) of different molecular weights, and 4,4’-bis-(6-hydroxyhexoxy)biphenyl (BHHBP) were prepared by a two-step solution polymerization process. The polyurethanes were characterized by elemental analysis, NMR, and SEC. The thermal properties were investigated by DSC, DMA, and optical polarizing microscopy. Dependent on the molecular weight of the PEA, a shift in the glass transition temperature T-g of the polyurethanes has been observed by DSC and DMA. Polyurethanes based on poly(butylene adipate)s of M(n) similar to 2000 exhibited a T-g nearly independent on the hard-segment content up to 50% LC hard segments, indicating the existence of mainly phase separated soft and hard segments. By shortening the PBA chain length up to 1,000 and further to 600, the T-g of the polyester soft-segment phase increases with growing hard-segment content, a consequence of enhanced interaction between the hard and soft segments. This tendency is observed to the greatest extent at polyurethanes with the shortest polyester diol and can be interpreted as a partial miscibility or compatibility of hard and soft segments. Although in polyurethanes with PBA 2000 the mesophase can be proven at a hard-segment content of similar to 40%, its appearance in polyurethanes prepared with PBA 1000 or PBA 600 requires a hard-segment content > 60%.