Syntheses and Properties of Novel Copolymers of Polylactide and Aliphatic Polycarbonate Based on Ketal-Protected Dihydroxyacetone

Abstract

The novel random copolymers of L-LA and 2, 2-ethylenedioxy-1, 3-propanediol carbonate (EOPDC) were synthesized in bulk using Sn(Oct)₂ as a catalyst. The poly(EOPDC -co- L-LA)s obtained were characterized by FT IR, ¹H NMR, ¹³C NMR, GPC and DSC. The copolymers were obtained with yield of 87.9–95.6%. The number average molecular weight of the copolymer is 1.85–6.18 × 10⁴ with a polydispersity of 1.41–1.73. The properties of the copolymer including the enzymatic degradation by proteinase K and drug-controlled release property were also investigated. The results show that the degradation rate of the copolymers increases with increasing LA content in the copolymers.

Keywords:

• 2,2-Ethylenedioxy-1,3-propanediol carbonate
• Aliphatic polycarbonate
• Degradation
• L-LA
• Ring-opening polymerization

ACKNOWLEDGMENTS

The authors are grateful for the financial support of the National Key Basic Research and Development Program (G1999064703) and Natural Science Foundation of China (Grant No. 20174029).

Notes

¹Sn(Oct)₂ as catalyst, molar ratio of monomer to catalyst [M]/[I] = 1000, 120°C, 24 h.

²Monomer feed ratio in mmol/mmol.

³Molar composition in the copolymer was determined by ¹H NMR.

⁴Number-average molecular weight and molecular weight distribution determined by GPC.