Structure and Mechanical Properties of Ethylene/1-Octene Multiblock Copolymers from Chain Shuttling Technology

• DOI: 10.1021/acs.macromol.8b02470
• Publication Date: 2019-03-18T17:44:39Z
• Authors: Finizia Auriemma; Claudio De Rosa; Miriam Scoti; Rocco Di Girolamo; Anna Malafronte; Massimo Christian...; Laura Boggioni; Simona Losio; Antonella Caterin...; Incoronata Tritto
• Keywords: Octene; 1-Octene; Chain (unit); Thermoplastic elastomer

The mechanical properties and the structural transformations occurring during deformation of some commercial grades ethylene/1-octene multiblock copolymers (OBCs) obtained from chain shuttling technology are analyzed. samples characterized by a statistical architecture, where soft amorphous blocks with high octene concentration (≈18.9 mol %) alternate hard crystalline low (≈0.5 %). length (BL) number blocks/chain (NB) change to according distribution. selected have molecular mass in range 85–130 kg/mol, percentage segments 15–27%, melting temperature ≈120 °C. average masses MH MS ranges 2–3 kg/mol 6–15 respectively, whereas is between 2 17. Even though similar concentration, small difference mass, fractional content blocks, they show remarkable differences properties, depending on BL NB values, encompassing those strong elastomers, case block blocks/chain, blocks/chain. OBC amplified stretching at temperatures. Not previously stretched films compression molding only partial recovery initial dimensions cycles releasing tension, values recovered strain higher than 50% 25 However, resultant specimens release tension good elastomeric wide °C and, strength, also 60 Fiber diffraction analysis reveals that orientation crystals accomplished formation an oriented phase, namely, involving extracted crystals. Upon recrystallization occurs, degree achieved phase lost.