Synthesis and mesomorphism of new aliphatic polycarbonates containing side cholesteryl groups

ABSTRACT

New cholesterol side-functionalised polycarbonate polymers were synthesised by the ring-opening homo- and copolymerisation reaction of the cyclic monomer cholesteryl 5-methyl-2-oxo-1,3-dioxane-5-carboxylate and d,l-lactide using Sn(Oct)₂ as a catalyst. The chemical structures and average molecular weights of the cyclic monomer, homopolymer and block copolymers obtained in this study were characterised using FT-IR, ¹H NMR and gel permeation chromatographic measurement. The mesomorphism and mesophase structure were investigated with polarising optical microscopy, differential scanning calorimetry and X-ray diffraction measurement. As a result, the homopolymer and block copolymers showed an enantiotropic smectic A (SmA) phase. With the concentration of the lactide segment increasing, the glass transition temperature and isotropic temperature of the corresponding block copolymer all decreased. In addition, XRD suggested that the homopolymer and two block copolymers showed the SmA double-layer packing of side chains.

GRAPHICAL ABSTRACT

KEYWORDS:

• Aliphatic
• polycarbonate
• liquid crystal
• cholesterol
• block copolymer

Disclosure statement

No potential conflict of interest was reported by the authors.

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Additional information

Funding

This work was supported by Science and Technology Bureau of Shenyang [grant number F14-231-1-05], and Fundamental Research Funds for the Central Universities [grant numbers N130205001 and N140502001].