The inclusion complexes (ICs) between polylactic acid (PLA) and β-cyclodextrin (CD) were prepared by coprecipitation method in this work. The orthogonal experiments were designed to investigate the influence of different factors on the formation of inclusion complexes. The results suggested that the optimum scheme of inclusion compounds could be obtained when the feeding ratio of CD to PLA (wt%) was 20:1, stirring speed was 6 kr/min and the stirring time was 30 min. The structures and properties of the inclusion complexes were characterized by 1H NMR, FTIR, DSC, FT-Raman, XRD and TGA. The DSC results demonstrated that the crystallization behavior of the inclusion complexes nearly disappeared. It was found that β-CD-PLA inclusion complex had a better thermal stability compared with the neat PLA. The model of the inclusion complexes was proposed on the basis of XRD, 1H NMR and DSC results.

Keywords: β-cyclodextrin; polylactic acid; co-precipitation method; inclusion complex; properties.