Abstract: Through a transesterification reaction in which a predetermined amount of bis(2-hydroxyethyl)terephthalate relative to glycol is fed in a divided or continuous manner, bis(glycol)terephthalate with a low residual amount of an ethylene glycol derivative is prepared, and polyester engineering products or biodegradable polyester products with high crystallinity can be produced therefrom.

Abstract: A recycled bis(4-hydroxybutyl)terephthalate according to an embodiment has a low residual amount of ethylene glycol derivatives, and thus, can be used as a polymerization raw material for high-crystallinity engineering polyester products or biodegradable polyester. Further the recycled bis(4-hydroxybutyl)terephthalate is easily crushed to produce flakes or powder, and provides excellent quality of, for example, colorand provides excellent quality of, for example, color.

Abstract: Provided is an aliphatic polycarbonate macropolyol including —OAO— and Z(O—)a as repeating units. In the aliphatic polycarbonate macropolyol, the repeating units —OAO— and Z(O—)a are linked to each other via carbonyl (—C(O)—) linkers or are bonded to hydrogen to form terminal —OH groups. The number of moles of the terminal —OH groups is from aZ to aZ+0.2Z (where Z represents the number of moles of the repeating unit Z(O—)a). Further provided is an aliphatic polycarbonate-co-aromatic polyester macropolyol including —OAO— and Z(O—)a as repeating units. In the aliphatic polycarbonate-co-aromatic polyester macropolyol, the repeating units —OAO— and Z(O—)a are linked via carbonyl (—C(O)—) and —C(O)YC(O)— as linkers or are bonded to hydrogen to form terminal —OH groups.

Abstract: The present invention relates to a novel group 4 transition metal compound, a method for preparing the compound, a catalyst composition containing the compound, and a method for preparing a polyolefin, comprising a step for forming a polymerization reaction of olefin monomers in the presence of the catalyst composition. The group 4 transition metal compound of the present invention exhibits an excellent catalytic activity and has excellent thermal stability in a polyolefin synthesis reaction, and thus can be used even in a polyolefin synthesis reaction at a high temperature. In addition, the compound of the present invention can be advantageously used in the synthesis process of grade-controlled polyolefin since the weight average molecular weight of the synthesized polyolefin and the octane content in the polymer can be adjusted by varying the kinds of center metal and ligand.

Abstract: Provided is an aliphatic polycarbonate macropolyol including —OAO— and Z(O—)a as repeating units. In the aliphatic polycarbonate macropolyol, the repeating units —OAO— and Z(O—)a are linked to each other via carbonyl (—C(O)—) linkers or are bonded to hydrogen to form terminal —OH groups. The number of moles of the terminal —OH groups is from aZ to aZ+0.2 Z (where Z represents the number of moles of the repeating unit Z(O—)a). Further provided is an aliphatic polycarbonate-co-aromatic polyester macropolyol including —OAO— and Z(O—)a as repeating units. In the aliphatic polycarbonate-co-aromatic polyester macropolyol, the repeating units —OAO— and Z(O—)a are linked via carbonyl (—C(O)—) and —C(O)YC(O)— as linkers or are bonded to hydrogen to form terminal —OH groups.

Abstract: Provided is an aliphatic polycarbonate macropolyol including —OAO— and Z(O—)a as repeating units. In the aliphatic polycarbonate macropolyol, the repeating units —OAO— and Z(O—)a are linked to each other via carbonyl (—C(O)—) linkers or are bonded to hydrogen to form terminal —OH groups. The number of moles of the terminal —OH groups is from aZ to aZ+0.2Z (where Z represents the number of moles of the repeating unit Z(O—)a). Further provided is an aliphatic polycarbonate-co-aromatic polyester macropolyol including —OAO— and Z(O—)a as repeating units. In the aliphatic polycarbonate-co-aromatic polyester macropolyol, the repeating units —OAO— and Z(O—)a are linked via carbonyl (—C(O)—) and —C(O)YC(O)— as linkers or are bonded to hydrogen to form terminal —OH groups.

Abstract: Provided is an aliphatic polycarbonate-co-aromatic polyester with long-chain branches. The copolymer includes repeating units represented by —OAO— and Z(O—)a, which are linked via carbonyl (—C(O)—) and —C(O)YC(O)— as linkers. Also provided is an aliphatic copolycarbonate including repeating units represented by —OAO— and Z(O—)a, which are linked via carbonyl (—C(O)—) linkers. The aliphatic copolycarbonate has a weight average molecular weight of 30,000 or more.

Abstract: The present invention relates to a novel group 4 transition metal compound, a method for preparing the compound, a catalyst composition containing the compound, and a method for preparing a polyolefin, comprising a step for forming a polymerization reaction of olefin monomers in the presence of the catalyst composition. The group 4 transition metal compound of the present invention exhibits an excellent catalytic activity and has excellent thermal stability in a polyolefin synthesis reaction, and thus can be used even in a polyolefin synthesis reaction at a high temperature. In addition, the compound of the present invention can be advantageously used in the synthesis process of grade-controlled polyolefin since the weight average molecular weight of the synthesized polyolefin and the octane content in the polymer can be adjusted by varying the kinds of center metal and ligand.

Abstract: Provided is an aliphatic polycarbonate-co-aromatic polyester with long-chain branches. The copolymer includes repeating units represented by —OAO— and Z(O—)a, which are linked via carbonyl (—C(O)—) and —C(O)YC(O)— as linkers. Also provided is an aliphatic copolycarbonate including repeating units represented by —OAO— and Z(O—)a, which are linked via carbonyl (—C(O)—) linkers. The aliphatic copolycarbonate has a weight average molecular weight of 30,000 or more.

Abstract: Provided is an aliphatic polycarbonate macropolyol including —OAO— and Z(O—)a as repeating units. In the aliphatic polycarbonate macropolyol, the repeating units —OAO— and Z(O—)a are linked to each other via carbonyl (—C(O)—) linkers or are bonded to hydrogen to form terminal —OH groups. The number of moles of the terminal —OH groups is from aZ to aZ+0.2Z (where Z represents the number of moles of the repeating unit Z(O—)a). Further provided is an aliphatic polycarbonate-co-aromatic polyester macropolyol including —OAO— and Z(O—)a as repeating units. In the aliphatic polycarbonate-co-aromatic polyester macropolyol, the repeating units —OAO— and Z(O—)a are linked via carbonyl (—C(O)—) and —C(O)YC(O)— as linkers or are bonded to hydrogen to form terminal —OH groups.