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Effect of polypropylene on the rheology of co‐continuous PS/SEBS blends
Author(s) -
Raha S.,
Kao N.,
Bhattacharya S.N.
Publication year - 2005
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.20409
Subject(s) - materials science , polypropylene , rheology , composite material , polystyrene , dynamic mechanical analysis , tacticity , dynamic modulus , izod impact strength test , polymer blend , styrene , phase (matter) , polymer chemistry , copolymer , polymer , ultimate tensile strength , chemistry , polymerization , organic chemistry
Polypropylene (PP) was added to a co‐continuous blend of polystyrene (PS) and styrene‐ethylene/butylene‐styrene (SEBS) to investigate the effect of PP on the morphology and rheological behavior of PS/SEBS blends. For this purpose, a reference blend of 50 wt% PS and 50 wt% SEBS was chosen and an isotactic PP was added to it by increments of 10 wt% up to a maximum of 50 wt% of the total weight. Environmental SEM (ESEM) studies on the PS/SEBS/PP blends showed that PP could be added up to 10 wt% without changing the morphology of the co‐continuous PS/SEBS blend, whereas at 20 wt% PP formed a separate discrete phase. The discrete PP phase finally formed a fully developed matrix structure from 40 wt% onwards. Dynamic rheological measurements showed that at low frequencies the storage modulus was largely unaffected by addition of PP in small concentrations (up to 10 wt%), showing a significant effect of the PP/SEBS interface at low deformation rates. Melt strength tests on the PS/SEBS/PP blends showed the existence of a proportional correlation with their corresponding storage moduli, measured at frequencies from 10–100 rad/s. POLYM. ENG. SCI., 45:1432–1444, 2005. © 2005 Society of Plastics Engineers