0000000000732957
AUTHOR
Friederike Von Gyldenfeldt
Thermal behavior and spherulitic superstructures of SBC triblock copolymers based on polystyrene (S), polybutadiene (B) and a crystallizable poly(ɛ-caprolactone) (C) block
The dynamic crystallization and the melting behavior of polystyrene-block-poly(e-caprolactone) (PS-b-PCL, short notation SC), polybutadiene-block-poly(e-caprolactone) (PB-b-PCL, BC) and polystyrene-block-polybutadiene-block-poly(e-caprolactone) (PS-b-PB-b-PCL, SBC) have been studied using differential scanning calorimetry. The copolymers with high molecular weight exhibit microphase separation into microphases consisting of polystyrene, polybutadiene and poly(e-caprolactone) and partial crystallization of the corresponding PCL block. The crystallization occurs at temperatures below the PS glass transition. Depending on the block copolymer composition, crystallization takes place through a c…
Synthesis of SBC, SC and BC block copolymers based on polystyrene (S), polybutadiene (B) and a crystallizable poly(ɛ-caprolactone) (C) block
The sequential anionic polymerization of polystyrene-block-polybutadiene-block-poly(e-caprolactone) (SBC) triblock copolymers as well as polystyrene-block-poly(e-caprolactone) (SC) and polybutadiene-block-poly(e-caprolactone) (BC) diblock copolymers was achieved in benzene. To initiate the polymerization of the highly reactive e-caprolactone, the nucleophilicity of the carbanion has to be reduced. For this purpose 1,1-diphenylethylene (DPE) was used. To avoid inter- and intramolecular transesterification reactions of the growing caprolactone block, the reaction time of this monomer in the block copolymers was strictly controlled. The reaction between polybutadienyl anions and DPE is too slo…