Facile synthesis of ethylene–propylene fully alternating copolymer and comparison with random copolymer of similar composition

Abstract

A precisely sequenced ethylene–propylene (EP) fully alternating copolymer was synthesized via trans‐1,4‐polymerization of isoprene catalyzed by Ziegler–Natta catalyst followed by hydrogenation. This EP copolymer was used as model polymer for studying structure–property relationship. An ethylene–propylene random copolymer (ethylene–propylene rubber [EPR]) with similar ethylene content was also prepared for comparison, and the effect of comonomer sequence distribution on properties was investigated. The copolymer chain structures were monitored by 1H and 13C NMR and Fourier translation infrared. Differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, and tensile tests were employed to determine the thermal and mechanical properties. The fully alternating copolymer EP gives a more precise glass transition comparing than EPR. Further understanding on thermal properties and aggregation behavior of ethylene–propylene copolymers is made possible by this comparative study. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45816.

Styrene‐Maleimide/Maleic Anhydride Alternating Copolymers: Recent Advances and Future Perspectives

“…Some of the alternating copolymer forming comonomer systems are electron donor‐acceptor pairs, [ 51 ] zwitterion intermediates, [ 52 ] metallocene or Ziegler–Natta catalyzed cis ‐olefins and ethylene, [ 53 ] complexes formed with Lewis acids, [ 54 ] etc. Among these, the systems of particular interest for this paper are electron donor‐acceptor pairs where electron acceptor monomers are MA, MI, or RMIs and electron donor monomer is S or substituted S. The copolymerization techniques for synthesizing such alternating copolymers and their developments in recent years are discussed below.…”