The conformation of polymer chains and the crystal forms of syndiotactic polystyrene (sPS)／isotactic polypropene (iPP) blends

prepared by reactor polymerization were investigated．Results indicated that the crystal forms of sPS and iPP in blends were similar to those in neat polymers．Both sPS and iPP in blends existed in α forms

which were not affected by blending．The results obtained from X-ray and FTIR measurements show that the crystallinity of sPS and iPP was reduced by blending．With increasing the sPS content

especially over 75％

the crystallinity of sPS and dimension of sPS crystals were evidently reduced．