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Three series of even-odd aliphatic copolyesters, poly(hexamethylene gluarate-co-hexamethylene pimelate) (PHGP), poly(hexamethylene pimelate-co-hexamethylene azelate) (PHPA), and poly(hexamethylene gluarate-co-hexamethylene azelate) (PHGA), were firstly synthesized derived from even diol of 1,6-hexanediol with odd diacids of glutaric acid, pimelic acid or azelaic acid, respectively. Then, their cocrystallization behaviors were systematically investigated by DSC, WAXD, and POM techniques. It is found that both PHGP and PHPA showed isodimorphism with a characteristic eutectic behavior observed from the plot of melting point versus composition, however, PHGA exhibited strict isomorphism in the whole composition range without a eutectic point. WAXD studies also confirmed the unique isodimorphism and isomorphism behaviors for even-odd copolyesters. The only slight change of the methylene number in alkyl unit of comonomers could generate so large difference in crystallization behavior, which exhibits unique physicochemical properties and structure-properties correlations in such even-odd copolyesters. Furthermore, the difference in cocrystallization miscibility effect of comonomers was analyzed by thermodynamics based on the defect Gibbs energy calculated from Wendling-Suter model. For PHGP and PHPA, the comonomer units have better miscibility in the case of the incorporation of shorter unit into the longer unit crystal than the opposite case. By contrast, in the case of PHGA, the HG and HA units are perfectly miscible in a same crystal lattice with only a little difference in crystal cell dimensions due to the identity of chain conformation of HG and HA units during packing into the crystal lattice. Finally, a model of crystal lattice structure of copolyesters was proposed to better understand the difference in cocrystallization miscibility effect of comonomers between isodimorphism and isomorphism.

In the present work, effects of the extract of green tea, one of the most popular beverages in peoples daily life, on the calcium oxalate (CaOx) crystallization were investigated by using field emission scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The experimental results showed that the tea extract (TE) was effective in directing CaOx crystallization from calcium oxalate monohydrate (COM) to calcium oxalate dihydrate (COD). Unusual morphological COD crystals were obtained in the presence of TE, but the morphological development did not consistently follow a TE concentration-dependent fashion. The complete transformation of gradually roughened COD bipyramids with layered {100} faces into larger porous COD bipyramids was achieved in the presence of the highest TE concentration, suggesting the existence of two different TE-mediated COD crystallization processes. These phenomena have not been reported previously, indicative of the unique impact of phenol-rich TE on CaOx crystallization. It is believed that the hydrogen bonds between the TE and CaOx host crystals play a pivotal role in prohibiting COM formation and in the morphological control of COD crystals. The hydrogen bonding interactions between the phenol groups of TE with the oxalate groups of CaOx were further discussed on the basis of FT-IR data.

To improve the hemocompatibility and biocompatibility of polyurethanes (PUs), PU surface was firstly modified by poly(ethylene glycol) PEG through acryloyl chloride and subsequently grafted on carboxymethyl-chitosan (CMCS). Attenuated total reflection Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis confirmed that carboxyl-chitosan was grafted onto PUs surface. The surface properties of unmodified and modified PU films were determined and compared by water contact angle assessment. After PEG and CMCS grafting, the surface energy of the PU film was increased. Furthermore, the hemocompatibility of the modified PU films was systematically evaluated by bovine serum albumin (BSA) adsorption, the dynamic blood clotting test, the platelet adhesion test, and the hemolytic test. It appears that BSA adsorption and platelet adhesion were significantly curtailed for the modified PU films. Therefore, the obtained results showed the modified PU film has better hemocompatibility.

Schematic model of mechanical performance of short fibre reinforced polyamide 6 composites for thermo-oxidative ageing at different ageing temperatures.

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