ABA triblock and diblock copolymers and methods of preparing the same

A method for preparing a triblock copolymer of the formula

• comprising:
• (a) contacting a cycloalkene with a chain transfer agent of the formula:
• Z—Y═Y—Z
• in the presence of a metal carbene metathesis catalyst to form a telechelic polymer;
• and
• (b) contacting the telechelic polymer with an alkene of the formula
• wherein
• n and m are integers;
• Z is an ATRP initiator;
• —Y═Y— is an alkenyl group;
• and
• R′ is selected from the group consisting of aryl, nitrile and C1-C20 carboxylate, wherein R′ is substituted or unsubstituted;
• and
• wherein the cycloalkene is 1,5-cyclooctadiene, Z is allyl chloride or 2-bromoisobutyrate and the alkene is styrene or methyl methacrylate.

A method for preparing a copolymer of the formula:

• comprising:
• (a) contacting a cycloalkene with a chain transfer agent of the formula:
• Z—Y═Y—Z′
• in the presence of a metal carbene metathesis catalyst to form a telechelic polymer;
• and
• (b) contacting the telechelic polymer with an alkene of the formula
• in the presence of an ATRP organometallic catalyst
• wherein
• n and m are integers;
• Z is an ATRP initiator;
• Z′ is hydrogen or a moiety selected from the group consisting of C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, aryl, C1-C20 carboxylate, C1-C20 alkoxy, C2-C20 alkenyloxy, C2-C20 alkynyloxy, aryloxy, C2-C20 alkoxycarbonyl, C1-C20 alkoxythio, C1-C20 alkylsulfonyl, C1-C20 alkylsulfinyl, wherein Z′ is substituted or unsubstituted;
• and
• R′ selected from the group consisting of aryl, nitrile and C1-C20 carboxylate,
• wherein R′ is substituted or unsubstituted.

A method for preparing a triblock copolymer of the formula:

• comprising:
• (a) contacting 1,5-cyclooctadiene with a chain transfer agent of the formula:
• Z—Y═Y—Z
• in the presence of a metal carbene metathesis catalyst to form a telechelic polymer;
• and
• (c) contacting the telechelic polymer with an alkene of the formula
• in the presence of an ATRP organometallic catalyst
• wherein n and m are integers;
• Z is allyl chloride or 2-bromoisobutyrate and —Y═Y— is an alkenyl group;
• the ATRP organometallic catalyst is CuCl/2,2′-bipyridine or CuBr/2,2′-bipyridine and, R′ is selected from the group consisting of aryl, nitrile and C1-C20 carboxylate, wherein R′ is substituted or unsubstituted.

A method for preparing an SBS triblock copolymer of the formula:

• comprising:
• (a) contacting 1,5-cyclooctadiene with a chain transfer agent of the formula:
• Z—Y═Y—Z
• in the presence of a ruthenium carbene metathesis catalyst to form a telechelic polymer;
• and
• (b) contacting the telechelic polymer with styrene in the presence of CuBr/2,2′-bipyridine.
• wherein n and m are integers;
• Z is chloride and —Y═Y— is an alkenyl group.