Ethylene-propylene copolymerization initiated with solubilized ziegler-natta macromolecular complexes. II. Characterization of [styrene]-b-[ethylene-co-propylene] copolymers

✍ Scribed by François Cansell; Alain Siove; Georges Belorgey

• Book ID: 105338214
• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 403 KB
• Volume: 28
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/polb.1990.090280505

✦ Synopsis

Abstract

Copolymerization of ethylene (E) with propylene (P) initiated with soluble (polystyrene)~100~‐butadiene~3~‐Li/TiCl~4~ complexes leads to [St]‐b‐[E‐co‐P] diblock copolymers with a random [E‐P] block. GPC and ^13^C‐NMR analyses of copolymers with various compositions and block lengths disclose well‐defined linear structures. From DSC measurements of such materials, three different endothermal transition regions are observed: two glass transition regions corresponding, respectively, to the T~g~ of styrenic and olefinic blocks, and one [E‐P] block melting region in which propylene units play a primary role. Furthermore, an additional endotherm is observed, depending on the thermal history of the sample.