A series of well-defined graft vinyl ester resins(graft VER)

i．e．butanol(BO)

poly(oxy-propylene) with different molecular weights (200 or 390)

which were simply called as 130-g-VER

200-g-VER and 390-g-VER respectively

consisting of different kinds and lengths of the side chains were synthesized and characterized．The simultaneous interpenetrating networks(SINs) of graft VER and polyurethane．urea (PUU) formed with toluene diisocyanate have been prepared．The effect of graft VER structure on the morphology and mechanical properties of PUU／graft VER SIN was studied through DSC and SEM observation etc．For PUU／BO-g-VER SIN

the BO-g-VER network is mainly interpenetrated and miscible with the hard segments of PUU network．For PUU／200-g-VER SIN

there have some interpenetration and miscibility between the 200-g-VER network and the hard segments as well as soft segments existing in the PUU network Thus

the strong reinforcement effect of these two graft networks on the PUU network was observed

and the mechanical properties of SINs were enhanced appreciably．There exhibited obvious phase separated morphology between the two networks in PUU／390-g-VER SIN

because of existing microphase separated morphology of 390-g-VER network in itself．In this case

theenhancement effect of such a graft VER network on the PUU network is limited