The hyperbranched polyester were synthesized by the "one-step method" and grafted with caprolactone (ε-CL) to obtain long-chain hyperbranched polymers (LCHBPs-Cl). LCHBPs-Cl was then melt blended with PLA to study its effect on the toughness of PLA. Compared to the pure PLA, the most significant toughening effect was observed when the addition amount of LCHBPs-Cl was 2.0phr. The tensile strength was increased by 69.21% from 37MPa to 62.61 MPa, the impact strength was increased from 14.88kJ to 18.50kJ. The scanning electron microscope (SEM) images showed that the impact section of the blends was changed from smooth to rough, the brittle-ductile fracture transition occurred, and a large number of white wire drawing phenomena were produced. Due to the formation of topological entanglement and cohesive entanglement between the long-chain substituents of LCHBPs-Cl and PLA molecular chains, the plastic deformation of PLA was successfully improved.

The hyperbranched polyester were synthesized by the "one-step method" and grafted with caprolactone (ε-CL) to obtain long-chain hyperbranched polymers (LCHBPs-Cl). LCHBPs-Cl was then melt blended with PLA to study its effect on the toughness of PLA. Compared to the pure PLA, the most significant toughening effect was observed when the addition amount of LCHBPs-Cl was 2.0phr. The tensile strength was increased by 69.21% from 37MPa to 62.61 MPa, the impact strength was increased from 14.88kJ to 18.50kJ. The scanning electron microscope (SEM) images showed that the impact section of the blends was changed from smooth to rough, the brittle-ductile fracture transition occurred, and a large number of white wire drawing phenomena were produced. Due to the formation of topological entanglement and cohesive entanglement between the long-chain substituents of LCHBPs-Cl and PLA molecular chains, the plastic deformation of PLA was successfully improved.

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