High-swelling-degree environment-friendly thermoplastic elastomer copolymer and preparation method thereof

The invention relates to the technical field of thermoplastic elastomer materials, in particular to a high-expansion-degree environment-friendly thermoplastic elastomer copolymer and a preparation method thereof.The high-expansion-degree environment-friendly thermoplastic elastomer copolymer is prepared from styrene-butadiene segmented copolymer, extending oil and an antioxidant, in the presence of an organic monolithium initiator, styrene is subjected to a first-stage polymerization reaction in an inert solvent, and a second-stage polymerization reaction is conducted; the preparation method comprises the following steps: carrying out a first-stage polymerization reaction on polystyrene to obtain a polystyrene-containing solution, adding butadiene into the polystyrene-containing solution, continuing a second-stage polymerization reaction to obtain a styrene-butadiene block copolymer-containing solution, adding a required amount of an antioxidant and extending oil into the styrene-butadiene block copolymer-con