Distribution of the number of arms of (PSt)f−n-star-(PIs)n hetero-star block copolymers prepared via anionic living polymerization of macromonomers

✍ Scribed by Kazunori Se; Akira Yoshizawa

• Book ID: 104088041
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 699 KB
• Volume: 50
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/j.polymer.2009.09.041

✦ Synopsis

The distributions of the number of arms (DNA) of (polystyrene) 6.2 -star-polyisoprene ((PSt) 6.2 -star-PIs) and (PSt) 7.6 -star-(PIs) 6.3 hetero-star block copolymers and its precursors prepared via anionic living polymerization of macromonomers have been determined by plotting a weight fraction of the number of arms against the number of arms. Three-dimensional molecular weight distributions (3D-M w D) of the two hetero-star block copolymers and its precursors were also determined by plotting a weight fraction at the ith elution volume against the corresponding molecular weight (M i ) and ith elution volume using GPC in conjunction with a low-angle laser light-scattering detector, a refractive index detector, and an ultraviolet detector. A non-linear relationship between the ith elution volume and M i of (PSt) 6.2 -star-PIs was observed and explained from a g star perspective. The present paper describes the analytical method for determination of the DNA using the M w D. The DNAs of the six samples were found to be narrow and similar to the M w Ds of the corresponding samples. The synthetic mechanism of the hetero-star block copolymers was discussed from a DNA perspective.