C. Koning et al., REACTIVE BLENDING OF POLY(STYRENE-CO-MALEIC ANHYDRIDE) WITH POLY(PHENYLENE OXIDE) BY ADDITION OF ALPHA-AMINO-POLYSTYRENE, Polymer, 34(21), 1993, pp. 4410-4416
Alpha-(3-Aminopropyl-1-amino)polystyrene (alpha-amino-PS) was melt-ble
nded with styrene/maleic anhydride copolymers (SMA) containing 28 wt%
maleic anhydride groups. The terminal primary amino group can react wi
th the maleic anhydride monomer units in SMA, forming imides. The resu
lting product turned out to be an efficient emulsifier for SMA blends
with poly(phenylene oxide) (PPO). At constant weight fraction of added
alpha-amino-PS, the size of the dispersed PPO particles decreased wit
h decreasing molar mass, i.e. increasing mole fraction, of the alpha-a
mino-PS. In a second series of experiments, alpha-amino-PS with M(n)BA
R > M(entanglement)BAR, was used to compatibilize SMA/PPO blends which
also contained poly(acrylonitrile-co-butadiene-co-styrene) and some p
oly[styrene-b-(ethylene-co-butylene)-b-styrene] triblock copolymer. Al
though, in this case, it was not possible to detect major changes in t
he phase texture or morphology, it could be shown that the addition of
alpha-amino-PS improved the impact strength significantly. For compar
ison, blends were also prepared with unmodified PS of a similar M(n)BA
R. No corresponding improvement of the mechanical properties was obser
ved in this case.