Details

Autor(en) / Beteiligte

• Marubayashi, Hironori
• Asai, Shigeo
• Hikima, Takaaki
• Takata, Masaki
• Iwata, Tadahisa

Titel

Biobased Copolymers Composed of l-Lactic Acid and Side-Chain-Substituted Lactic Acids: Synthesis, Properties, and Solid-State Structure

Ist Teil von

• Macromolecular chemistry and physics, 2013-11, Vol.214 (22), p.2546-2561

Ort / Verlag

Weinheim: Blackwell Publishing Ltd

Erscheinungsjahr

2013

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• Various biobased copolyesters composed of l‐lactic acid (LLA) and side‐chain‐substituted lactic acids (SLAs) with high molecular weight and LLA‐rich composition are synthesized by direct solution polycondensation. Glycolic acid, 2‐hydroxyisobutyric acid, (S)‐2‐hydroxy‐3‐methylbutanoic acid (LVOH), and (S)‐2‐hydroxy‐4‐methylpentanoic acid (LLOH) are chosen as SLAs. Wide‐angle X‐ray diffraction (WAXD) and small‐angle X‐ray scattering (SAXS) reveal that the substituent size of the SLAs determines whether or not SLA units are included in crystallites of the LLA sequences. Unlike poly(l‐lactic acid), tensile necking is seen in the copolymers with 2 mol% LVOH and with 6 mol% LLOH. Enzymatic degradation is accelerated with increasing SLA content. Especially for 6 mol% LLOH, the SLA introduction improves both the mechanical properties and the enzymatic degradability. Various biobased copolyesters composed of l‐lactic acid and side‐chain‐substituted lactic acids (SLAs) [glycolic acid, 2‐hydroxyisobutyric acid, (S)‐2‐hydroxy‐3‐methylbutanoic acid, and (S)‐2‐hydroxy‐4‐methylpentanoic acid (LLOH)] with high molecular weight are synthesized, and their structure and properties are systematically investigated. Especially for 6 mol% LLOH, both the mechanical properties and the enzymatic degradability are greatly improved.