US-12617888-B2 - Poly(lactic acid-b-3-hydroxypropionic acid) block copolymer having excellent transparency property and products containing the same

Abstract

Provided is a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer in which transparency is improved by introducing a 3-hydroxypropionic acid-derived monomer into a polylactic acid, and thus its application field can be expanded.

Inventors

• Jung Yun CHOI
• Yeonju LEE
• Solyi PARK
• Chul Woong KIM
• Donggyun KANG

Assignees

• LG CHEM, LTD.

Dates

Publication Date

20260505

Application Date

20220224

Priority Date

20210224

Claims (9)

1. 1 . A poly(lactic acid-b-3-hydroxypropionic acid) block copolymer of the following Chemical Formula 1, wherein UV transparency of the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer is 80% or more: wherein in Chemical Formula 1: m is an integer of 100 to 1000; n is an integer of 500 to 4000; and m/n is 0.05 to 0.20.
2. 2 . The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer of claim 1 , wherein m is 120 to 350.
3. 3 . The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer of claim 1 , wherein n is 1000 to 2500.
4. 4 . The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer of claim 1 , wherein elongation of the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer is 1% to 250%.
5. 5 . The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer of claim 1 , wherein elongation of the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer is 5% to 35%.
6. 6 . The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer of claim 1 , wherein tensile strength of the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer is 30 MPa to 60 MPa.
7. 7 . The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer of claim 1 , wherein tensile modulus of the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer is 1.5 GPa to 2.5 GPa.
8. 8 . The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer of claim 1 , wherein a weight average molecular weight of the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer is 50,000 to 350,000.
9. 9 . An article, comprising the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer of claim 1 .

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a National Stage Application of International Application No. PCT/KR2022/002696 filed on Feb. 24, 2022, which claims priority to and the benefits of Korean Patent Application No. 10-2021-0024929, filed on Feb. 24, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety. TECHNICAL FIELD The present invention relates to a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer having excellent transparency property and articles including the same. BACKGROUND Polylactic acid (PLA) is a plant-derived resin obtained from plants such as corn, etc., and receives much attention as an excellent eco-friendly material because it has biodegradable properties. Unlike existing petroleum-based resins generally used, such as polystyrene resins, polyvinyl chloride resins, polyethylene, etc., polylactic acid has effects of preventing the depletion of petroleum resources and suppressing carbon dioxide emission, etc., and therefore, it can reduce environmental pollution, which is a disadvantage of petroleum-based plastic products. As the environmental pollution problems caused by waste plastics, etc. have emerged as social problems, efforts are being made to expand the range of application of polylactic acid to products where general plastics (petroleum-based resins) have been used, such as food packaging materials and containers, electronic product cases, etc. However, polylactic acid has poor impact resistance and heat resistance, as compared to existing petroleum-based resins, and thus it has a limited range of application. In addition, its tensile strength is weak and transparency is required depending on the application field. Since it is difficult to control the physical properties of polylactic acid, polylactic acid has a limitation as a general-purpose resin. In order to improve the above disadvantages, studies have been conducted on a copolymer by including other repeating units in polylactic acid, and in particular, 3-hydroxypropionic acid received attention as a comonomer. However, polylactic acid expresses different physical properties depending on the degree of introduction of 3-hydroxypropionic acid. When the degree of introduction thereof is not controlled, the intrinsic physical properties of the polylactic acid are deteriorated. Accordingly, the present invention is intended to provide a block copolymer having excellent physical properties such as transparency, etc., while maintaining the intrinsic physical properties of polylactic acid by controlling the degree of introduction of a 3-hydroxypropionic acid-derived monomer. BRIEF DESCRIPTION Technical Problem Provided is a copolymer having excellent physical properties such as transparency, etc., while maintaining the intrinsic properties of polylactic acid, and an article including the same. Technical Solution To achieve the above object, provided is a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer of the following Chemical Formula 1, wherein the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer has UV transparency of 80% or more: wherein in Chemical Formula 1:m is an integer of 100 to 1000; andn is an integer of 500 to 4000. DETAILED DESCRIPTION As used herein, the term ‘poly(lactic acid-b-3-hydroxypropionic acid) block copolymer’, which is a block copolymer obtained by polymerizing a lactide-derived monomer and a 3-hydroxypropionic acid-derived monomer, as shown in Chemical Formula 1, refers to a block copolymer, in which various physical properties of polylactic acid are controlled by introducing the 3-hydroxypropionic acid-derived monomer. When the 3-hydroxypropionic acid-derived monomer is introduced as a comonomer of polylactic acid, various physical properties of polylactic acid can be improved, but the expressed physical properties can differ depending on the degree of introduction. Accordingly, in the present invention, the degree of introduction of the 3-hydroxypropionic acid-derived monomer can be controlled to control physical properties such as transparency, etc., while maintaining the intrinsic physical properties of polylactic acid. Preferably, m is 120 to 350. m means the number of repeats of the 3-hydroxypropionic acid-derived monomer. When the 3-hydroxypropionic acid-derived monomer is introduced in the above range, it is possible to control physical properties such as transparency, etc., while maintaining the intrinsic physical properties of polylactic acid. More preferably, m is 130 or more, 140 or more, 150 or more, 160 or more, 170 or more, 180 or more, 190 or more, or 200 or more; and 340 or less, 330 or less, 320 or less, 310 or less, or 300 or less. Preferably, n is 1000 to 2500. n means the number of repeats of the lactide-derived monomer. More preferably, n is 1100 or more, 1200 or more, 130 or more, 1400 or more, or 1500 or more; and 2400 or less, 2300 or less, 2200 or less, 2100 or less, or 2000 or less. Further, i