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Liao G.,Wuhan University | Jiang K.,Wuhan University | Jiang S.,Hubei Research Institute of Chemistry | Xia H.,Wuhan University
Journal of Macromolecular Science, Part A: Pure and Applied Chemistry | Year: 2010

A series of multi-block copolymers, poly(L-lactide)-b-poly (-caprolactone) (PLLA-b-PCL) were synthesized. The first step of the synthesis consisted of the transesterification between the PLLA and 1,4-Butanediol, followed by the copolymerization of PLLA-diols and PCL, using isophorone diisocyanate (IPDI) as a coupling agent. The synthesized polymers were characterized by Fourier transform infrared (FTIR) spectra, differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD). PLLA/PCL block copolymers were electrospun into ultrafine fibers. The morphology of the electrospun fibrous scaffolds were investigated by Scanning Electron Microscopy (SEM). Results showed that the morphology and diameter of the fibers were affected by the electrospinning solution concentrationan and different weight ratio of PLLA/PCL. These electrospun PLLA-b-PCL fibrous membranes exhibited good flexibility and deformability. In comparison with the electrospun PLLA membrane, the electrospun fibrous membranes of PLLA-b-PCL demonstrated an enhanced elongation with still high tensile strength and Young's modulus to be beneficial for tissue engineering scaffolds. Copyright © Taylor & Francis Group, LLC. Source


He X.,Wuhan University | Zhong M.,Hubei Research Institute of Chemistry | Zhang T.,Wuhan University | Yang J.,Hubei University for Nationalities | And 5 more authors.
European Journal of Medicinal Chemistry | Year: 2012

In the present study on the development of new anticonvulsants, 16 new1-(8-(benzyloxy)quinolin-2-yl-6-substituted-4,6-diazaspiro[2,4]heptane-5, 7-diones were synthesized and tested for anticonvulsant activity using the maximal electroshock (MES), subcutaneous pentylenetetrazole (scPTZ) screens, which are the most widely employed seizure models for early identification of candidate anticonvulsants. Their neurotoxicity was determined applying the rotorod test. Two compounds 8e and 8j showed promising anticonvulsant activities in both models employed for anticonvulsant evaluation. The most active compound 8e showed the MES-induced seizures with ED 50 value of 8.6 mg/kg and TD 50 value of 365.3 mg/kg after intraperitoneally injection to mice, which provided compound 8e with a protective index (TD 50/ED 50) of 26.8 in the MES test. © 2011 Elsevier Ltd. All rights reserved. Source


Huang Y.,Wuhan University | Zeng M.,Wuhan University | Zeng M.,University of Sichuan | Ren J.,Wuhan University | And 4 more authors.
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2012

A series of novel graphene oxide (GO)/poly(acrylic acid- co-acrylamide) super-absorbent hydrogel nanocomposites were prepared by in situ radical solution polymerization. The effects of GO content on the chemical structure, morphology and miscibility of the hydrogels were studied. The swelling behaviors, swelling kinetics and pH-responsive behaviors of the hydrogels were also evaluated. Owing to the hydrogen bonds and possible covalent bonds between GO and polymer chains, relatively lower content (<0.30. wt%) of GO could be dispersed well in the polymer matrix and enhanced the intermolecular interactions between the components effectively. On the contrary, an excessive amount of GO might form large agglomerates and weakened the interfacial interactions, resulting in the micro-phase separation between the components. Furthermore, the swelling capacities and swelling rates of hydrogels went up with increasing GO loadings to 0.30. wt% and then decreased with further increasing GO loadings. It is worth noting that the hydrogel only containing 0.10. wt% GO exhibited significant improvement of swelling capacity in neutral medium, and could also retain relatively higher swelling capacities to a certain degree at acidic and basic solutions. Therefore, the as-prepared GO-based super-absorbent hydrogels might have potential applications in many areas, such as biomedical engineering, construction engineering and hygienic products. © 2012 Elsevier B.V. Source


Zeng M.,Wuhan University | Zeng M.,University of Sichuan | Wang J.,Wuhan University | Li R.,Wuhan University | And 5 more authors.
Polymer (United Kingdom) | Year: 2013

Two series of benzoxazine (BOZ) based composites were prepared with graphene oxide (GO) and graphite via in situ intercalative polymerization. Based on isothermal and non-isothermal mode Differential Scanning Calorimetry results, BOZ with the addition of GO could not only decrease the cure temperature, but also increase the cure rate of BOZ. On the contrary, BOZ with the addition of graphite would delay the polymerization of BOZ monomer. It was hypothesized that carboxyl groups of GO acted as weak organic acid which accelerated the ring opening procedure. Interestingly, BOZ/GO composite with 1 wt% GO occupied the least time to form polymer networks, attributing to the catalytic effect and good dispersion of GO. Moreover, BOZ with 1 wt% content of GO had relatively higher glass transition temperature and char yield than those of the corresponding BOZ/graphite sample, which was due to relatively stronger intermolecular interactions between GO and BOZ. © 2013 Elsevier Ltd. All rights reserved. Source


Jiang S.,Wuhan University | Jiang S.,Hubei Research Institute of Chemistry | Liao G.,Wuhan University
Polymer - Plastics Technology and Engineering | Year: 2012

A series of multiblock copolymer, Poly(L-lactide)-b-Poly(ethylene glycol) (PLLA-b-PEG) were synthesized and characterized by Fourier transform infrared spectra, differential scanning calorimetry and wide angle X-ray diffraction. PLLA-b-PEG fibrous scaffolds were prepared by electrospinning. The morphology of the fibers was affected by the solution concentration and different weight ratio of PLLA/PEG. In comparison with the electrospun PLLA membrane, the electrospun fibrous membranes of PLLA-b-PEG demonstrated an enhanced water absorption percentage and reductive water contact angle. The electrospun PLLA-b-PEG with weight ratio 90/10 and 75/25 fibrous membranes exhibited good flexibility and deformability to be beneficial for tissue engineering scaffolds. © 2012 Copyright Taylor and Francis Group, LLC. Source

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