Synthesis of poly(lactic acid)–poly(ethylene glycol) copolymers using multi-SO3H-functionalized ionic liquid as the efficient and reusable catalyst

• Published in: Polymer bulletin (Berlin, Germany) Vol. 71; no. 5; pp. 1173 - 1195
• Main Authors: Ren, Hui-xue, Ying, Han-jie, Sun, You-min, Wu, Dao-ji, Ma, Yong-shan, Wei, Xiao-feng
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2014; Springer; Springer Nature B.V
• Subjects: Applied sciences; Catalysis; Catalysts; Catalytic activity; Caustic soda; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry; Chemistry and Materials Science; Complex Fluids and Microfluidics; Contact angle; Copolymerization; Copolymers; Degree of crystallinity; Efficiency; Exact sciences and technology; Ionic liquids; Lewis acid; Mechanical properties; Molecular weight; Organic Chemistry; Organic polymers; Original Paper; Physical Chemistry; Physicochemistry of polymers; Polycondensation; Polyethylene glycol; Polylactic acid; Polymer Sciences; Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts; Reaction kinetics; Soft and Granular Matter; Sulfonic acid; H; PLA–PEG; Multi-SO; Efficient; Recycle; Ionic liquid; Imidazole derivatives; Catalytic reaction; Molecular structure; Iminium compounds; Lactic acid copolymer; Mechanical properties; Condensation polymerization; Crystallinity; Ethylene oxide copolymer; Experimental study; Sulfonate; Ethylene oxide polymer; Wettability; Cyclic ether polymer; Cyclic ether copolymer; Aliphatic polymer; Preparation; Surface properties; Kinetics; Catalyst activity; Activation energy
• ISSN: 0170-0839; 1436-2449
• DOI: 10.1007/s00289-014-1117-2

Poly(lactic acid)–poly(ethylene glycol) copolymers were synthesized under the catalysis of multi-SO 3 H-functionalized ionic liquid. Compared to the ordinary ionic liquids and the traditional Lewis acid catalysts, the ionic liquids with multi-sulfonic acid groups were more catalytically active, and the reaction conversion rate reached up to 97.8 %. The molecular weight of the resulting copolymer was 5.69 × 10 4  g mol −1 and the degree of crystallinity was 42.9 %. The copolymers were also of higher hydrophilicity and better mechanical properties. The reaction kinetics of copolymerization was analyzed. The intrinsically high catalytic activity of multi-SO 3 H groups originated from the lower activation energy and the higher free acidity. The recovering catalytic activity of the multi-SO 3 H ionic liquid catalyst was higher, suggesting that it is a recyclable, environmentally friendly catalyst.