Synthesis And Characterization Of Star Copolymers

Polyamidoamine(PAMAM)-based dendrimer is a class of macromolecules with controlled surface functionality and size, highly branched and three-dimensional architecture, which has attracted a lot of scientific attention in the past decade and provided a number of potential application prospects in wide areas. Cyclodextrins coating on the Star polymer can get more complex supramolecular structure. These copolymers possess unique physical and chemical properties, which will extend the application scope of aliphatic polyesters and enrich the design and tailor contents of molecular.Dendrimer-star copolymers were synthesized by ring-opening polymerization, which used hydroxyl-terminated dendrimer polyester as initiator. Finally,α-Cyclodextrin (α-CD) was thread onto the macromer (PAMAM- PCL) which could get star-poly(pseudo)rotaxanes complexα-CDPAMAM-PCL. Structure of PAMAM,PAMAM-OH,PAMAM-PCL andα-CD-PAMAM-PCL were characterized and analysised by patterns of ~1H NMR, FTIR and GPC. The results indicate that the PAMAM-PCL can be successfully coated withα-CD. Because of its excellent biocompatibility, such fine structures of the copolymer component, can have potential applications in biological materials. The performance characterization of copolymers by DSC and TG showed that these copolymers possess unique thermal properties which were different from those of linear PCL; the crystallizability of PCL segments was hindered seriously. Use of PLM and XRD to characterize, PAMAM-PCL and linear PCL have the same crystal structure, indicating that the star structure does not change the crystalline structure of PCL; Whenα-CD coating onto the surface of PAMAM-PCL, PCL crystalline morphology disappeared. By DLS and AFM characterization and data calculation, it can be inferred that there are 5 CLs withoutα-CD coating on the side chain ofα-CD-PAMAM-PCL. .