"Preparation and characterization of poly (L-lactide)-ε-caprolactone / DL-lactide copolymer-poly(L-lactide) thermoplastic elastomers"

Abstract

Using stannous octanoate as catalyst and 1,4-butanediol as initiator, ring-opening polymerization of ε-caprolactone and DL-lactide was carried out to prepare ε-caprolactone and DL-lactide copolymer with hydroxyl groups at both ends (PCDLA-OH prepolymer), and then L-lactide ring-opening polymerization was initiated by PCDLA-OH prepolymer to prepare triblock copolymer with poly L-lactide segments at both ends and ε-caprolactone and DL-lactide copolymer in the middle (PLLA-b-PCDLA-b-PLLA) was prepared, and the structure and properties of the block copolymer were tested. The results showed that the larger the amount of DL-lactide in PCDLA-OH prepolymer, the prepolymer gradually changed from partial crystallization to amorphous polymer, and the glass transition tempe-rature gradually increased. When the mole ratio of DL-lactide to ε-caprolactone was 3/10 and the mass ratio of PCDLA-OH prepolymer to L-lactide was 1/5, the elongation at break and tensile strength of the prepared PLLA-b-PCDLA-b-PLLA were 204% and 4.77 MPa.

Keywords

• ε-caprolactone
• dl-lactide
• l-lactide
• ring-opening polymerization
• thermoplastic elastomer
• block copolymer