Synthesis And Characterization Of Calix[4] Resorcinarene-Poly-L-Lactide,Liquid Crystal Materials

Poly-L-lactic acid (PLLA) had attrated much interests for long time because of their huge optical rotation power and high-speed electro-optic modulate property. PLLAs are also biological active and ideal sustained release polymer. In this work series of Calix[4]resorcinarene-Poly-L-Lactic acid were synthesized and their liquid crystalline, thermal properties, optical activity and so on were studied. Then, Calix[4]resorcinarene-Poly-L-Lactic acid and PLLAx-PEGy-PLLAx block copolymer material as controlled release system for targeted drug controlled release were researched by preparing magnetite microsphere loaded drug.The first, Acid catalyzed condensation of butyraldehyde and resorcinol were performed to give calix [4]resorcinarene, then derivatization of calix [4]resorcinarene were modified to attach reactive hydroxyl for the initiation of the ring-opening polymerization of L-LA. Series of Calix[4]resorcinarene-Poly-L-Lactic acid (4m[C4]-(O2OLAxOH8, x=10,20,30,40,60) were obtained by changing the feed ratios of LLA to HO-groups.Ⅰ. Proton magnetic resonance spectroscopy (1H NMR), Fourier transform infrared spectroscopy (FTIR), Atomic force microscope (AFM) were used to investigate the chemical structure of 4m[C4]-(O2OLAxOH)8. The disappearance of-CH2CH2OH proton peaks in 1H NMR indicates that all -CH2CH2OH initiate the ring-openning polymerization of L-LA. AFM observation showed that 4m[C4]-(O2OLAxOH)8 molecules as separated particles approximate round shaped instead of rod-like one,which proved that the successful synthesization of 4m[C4]-(O2OLAxOH8 with eight identical O-LLA arms.Ⅱ. By Combining 1H NMR with Gel permeation chromatography (GPC) methods we characterized the molecular weight of 4m[C4]-(O2OLAxOH)8 and the results showed that the molecular weights of 4m[C4]-(O2OLAxOH)8 were controllable and narrow polydispersed with index from 1.1 to 1.5.Ⅲ. Thermal behavior of the eight armed OLLA materials determined by DSC and POM revealed that the eight armed core part had strong spatial effect on the OLLA arms attached and their crystallization behavior was greatly reduced until the DP of the segments reach to 60. The sharp peaks observed at small angle area around 1.9°in SAXD experiments for some annealed samples indicates the presence of layer structure, a smectic liquid crystal phase.IV. The circular dichroism (CD) of the original samples 4m[C4]-(O2OLAxOH)8 in acetonitrile solution presents only one peak at 210nm as the typically positive cotton effect of the OLLA segments. The mean residual ellipticity [0] of these peaks, from 6000 to 11000 degree·cm2·decimol-1, are relatively higher comparing to those of OLLA segments,4000 to 5000 degree·cm2·decimol-i, which with common linear molecular conformation.The second. Series of PLLA-PEG-PLLA block copolymers prepared by ring-opening polymerization of L-LA, with polyethylene glycols (PEG) of different molecular weights as the initiator, SnOct2 as co-initiator. B 1H NMR, DSC we determined the molecular weights and thermal properties of PLLA-PEG-PLLA, correspondingly.The third, the preparation of targeted anti-cancer drug controlled release microcapsules and nanoparticlesⅠ. By optimizing the preparation conditions of magnetic iron oxide we obtained nanoparticles of Fe3O4, less than about 10nm and 10～30 nm, spherical or rod-like morphology. Saturation magnetization of magnetic iron oxide is up to 20 emu/mg. TG-DSC were used to measure the content of Fe3O4 and found that the ratio of AOT coated on magnitite is 60% to 70%.Ⅱ. In this part controlled-release anti-cancer drug microencapsules containing magnetic iron oxide-oriented material with diameter of 2～8μm were also prepared by solvent-evaporation method.