Polyurethane uniqueness is given by their segregated structure, with two kinds of domains: soft segments and hard segment domains. It is well-known that this morphology originates from the formation of hydrogen bonds between complementary parts of the polymer structure. Hard domains function as physical crosslinks for flexible, soft blocks. As long as this hydrogen bond physical network is not affected, the molecular dynamics of polyurethanes is barely influenced by any structural modification [1,2]. Dynamic mechanical analysis is largely used to examine the molecular dynamics of polyurethanes. By the adequate selection of experimental condition (frequency, heating rate), the results of a DMA investigation allow to distinguish between kinetic/relaxation phenomena (glass transition/melting, flowing), to separate the glass transition regions of overlapping domains, to identify processes than can take place in the region considered stable for polyurethanes (rubbery region)[3-5]. In the same direction, the presentation aims to put forward how different loading types (tension, shear, bending) could shed more light on the structural changes that occur in a polyurethane during a DMA temperature scanning experiment. The experiments were undertaken on polyurethanes based on aliphatic prepolymers, obtained from poly(tetramethylene ether glycol) (PTMG) and hexamethylene diisocyanate (HDI). The physical crosslinking degree is tuned by including include chain extenders with increasing nucleophylic capacity (1,6-hexanediol, HD; triethylene glycol,TEG; 3,6-dithio-1,8-octanediol, DTO).