Several aliphatic waterborne polyurethanes were prepared from isophorone diisocyanate (IPDI)

dimethylolpropanic acid (DMPA)

poly (ethylene adipate) (PEA) and polypropylene glycol (PPG)．Dynamic mechanical analysis(DMA) was adopted to study the relationships between morphology and properties of aliphatic waterborne polyurethanes．The results indicated that the interaction between soft and hard segments depended heavily on the structure of soft segments．The carbonyl of polyester-type diols can form hydrogen bonds with hard segments

which lead to a semi-compatible structure

whereas the hydrogen bonding in the polyether-based polyurethanes is formed mainly between the hard segments

which results in higher level microphase separation．The ionic groups incorporated in the hard segments improve the phase separation．As a result

the increase of DMPA amount is related with a lower glass transition temperature (Tgs) and a higher i>Tgh．At the meantime

the level of microphase separation increases with the increasing of soft segments length．