Polymorphic crystal forms and morphology of syndiotactic polystyrene in miscible states

✍ Scribed by E. M. Woo; Fu Sun Wu

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 366 KB
• Volume: 36
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(19981115)36:15<2725::aid-polb6>3.0.co;2-k

✦ Synopsis

X-ray diffraction and optical microscopy characterization were performed to evaluate the phenomenon of alteration of polymorphism of syndiotactic polystyrene (s-PS) in the presence of other blending miscible polymers: poly(2,6-dimethyl-pphenylene oxide) (PPO) or atactic polystyrene (a-PS). Both ␣ and ␤ crystal forms were observed in the neat s-PS sample, but only ␤-form crystal was found in miscible blends of s-PS with a-PS or PPO. The order and neighboring chain segments of neat s-PS are different from those of s-PS/PPO or s-PS/a-PS blends; thus, it is plausible that the greater randomness in the melt state of s-PS/a-PS or s-PS/PPO blends might be unfavorable for formation of ␣-form crystals from melts. The final spherulitic morphology the s-PS/a-PS or s-PS/PPO blends suggests that the amorphous-state miscibility of does not change much the spherulitic structure of s-PS. The radial growth rate is, in general, depressed with the presence of blending miscible polymers in s-PS of equal T g or PPO of higher T g .