Abstract: Provided is a method for preparing an oligomer including: supplying a monomer stream and a solvent stream to a reactor to perform an oligomerization reaction to prepare a reaction product; supplying a discharge stream from the reactor including the reaction product to a separation device and supplying a lower discharge stream from the separation device to a settling tank; adding an organic flocculant to the settling tank to settle and remove a polymer and supplying the lower discharge stream from the separation device from which the polymer is removed to a high boiling point separation column; and removing a high boiling point material from the lower portion in the high boiling point separation column and supplying an upper discharge stream including an oligomer to a solvent separation column.

Abstract: Provided is a method of producing an oligomer, the method including: supplying a monomer stream and a solvent stream to a reactor to perform an oligomerization reaction to produce a reaction product; supplying a discharge stream of the reactor to a separation device, and supplying an upper discharge stream of the separation device including an unreacted monomer to the reactor and supplying a lower discharge stream of the separation device to a settling tank; settling a polymer in the settling tank and removing the polymer, and supplying the lower discharge stream of the separation device from which the polymer is removed to a high-boiling point separation column; removing a high-boiling point material from a lower discharge stream of the high-boiling point separation column and supplying an upper discharge stream of the high-boiling point separation column including an oligomer to a solvent separation column; and separating a solvent and the oligomer in the solvent separation column.

Abstract: A core-shell copolymer, a method of making the same, and a thermoplastic resin composition including the same are disclosed herein. In some embodiments, a core-shell copolymer includes a core and a shell surrounding the core, the core includes a conjugated diene-based monomer-derived repeating unit and a phosphate-based cross-linking agent-derived cross-linking part represented by Formula 1, and the shell includes a first alkyl (meth)acrylate monomer-derived repeating unit, a second alkyl (meth)acrylate monomer-derived repeating unit, and a sulfonate-based ionic monomer-derived repeating unit represented by Formula 2. The core is 68 parts to 92 parts and the shell is 8 parts to 32 parts, based on 100 parts of the core-shell copolymer, the core has a swell index of 2.7 to 10.9, the shell includes 1 wt % to 16 wt % of the sulfonate-based ionic monomer-derived repeating unit, and the shell has a weight average molecular weight of 105,000 g/mol to 645,000 g/mol.

Abstract: Disclosed is a magnetostrictive transducer for generating and receiving elastic waves in a testing plate and an apparatus for structural diagnosis using the magnetostrictive transducers. More particularly, disclosed is a magnetostrictive transducer which may generate and transmit elastic waves using the magnetostrictive effect in any directions without re-attaching ferromagnetic patch on the non-magnetic testing plate and may produce Lamb waves and Shear Horizontal (SH) waves in desired directions, and an apparatus for structural diagnosis using the magnetostrictive transducers. There is provided a magnetostrictive transducer comprising: a patch made of ferromagnetic material; and a magnetic field generator for generating magnetic field applied to the patch, the magnetic field generator being placed on the patch, wherein the magnetic field generator comprises: a main body; two magnets for generating bias magnetic field, the magnets being apart from each other; and a coil for winding around the magnets.