Modified polyether polyurethane and its film were prepared from prepolymer of amino-terminal non-isocyanate polyurethane and prepolymer of polyether-based polyurethane via block copolymerization.Synthesis condition of non-isocyanate prepolymer was analyzed;The impact of film-forming temperature and value of NCO and NH2 ratio on mechanical properties of membrane were investigated;Mechanical properties of different polyurethane materials were compared;Degree of phase separation was studied using differential scanning calorimetry(DSC).It showed that carbamate group was introduced into the amino-terminal non-isocyanate prepolymer;The best film-forming temperature was 140 ℃;When NCO/NH2 of prepolymer was 1/0.9,the best performance was obtained,tensile strength of 25.1 MPa,modulus of 100 % elongation of 5 MPa.Compared with regular polyurethane,polyurethane block with amino-terminal non-isocyanate polyurethane prepolymer had higher mechanical properties;DSC curves showed two different glass transition temperatures indicating phase separation.
Nanometer ZnO with different sizes and shapes are prepared by deposition method.These Nanometer ZnO samples are characterized by AFM and XRD.They are made to be coat by indicats that,light absorbability of nanometer ZnO becomes better when the particle-size becomes smaller,and slice nano-ZnO has stronger absorbability than spherical nano-ZnO.
Aniline can be polymerized by either an electrochemical or a chemical oxidation process.This paper describes a unique process of chemical oxidation polymerization of polyaniline using manganese dioxide as the oxidizing agent in the aqueousmedia.The reaction between aniline and manganese dioxide follows the well-known mechanism,by which the metal oxide undergoes reductive in solution when the organic monomeris is oxidized. The effect of the dosage of oxidizing agent, pH of reactive system, temperature of reaction on the yield and conductivity of polyaniline there of are discussed. The obtained polyaniline is characterized by IR spectra. Polyaniline with the conductivity12.5S/cm is obtained using 0.033mol of aniline oxidized by 2g manganese dioxide in the present of 2.7mol/LHCl at the temperature of 25℃ for 4h.
[Objective] To study tha external anti-bacterial activity of bakuchiol and baicalin in acne.[Methods] The colony counting method was applied to determine the inhibitory ratio against staphylococcus epidermidis and propioni-bacterium acnes growth by adding the mixed solution with different concentrations of bakuchiol and bakuchiol-baicalin. [Results] The inhibitory ratios against staphylococcus epidermidis and propionibacterium acnes growth were 100.0% and 61.1% with 2 560 mg/L bakuchiol solution. Two kinds of acne bacteria inhibitory rate were 100.0% under the mixed solutions with the bakuchiol concentration of 2 560 mg/L and baicalin 800 mg/L. In particular, the propionibacterium acnes inhibitory rate was improved for 1.64 times than single bakuchiol.[Conclusion] The increasing of the inhbitory rate in combination of a certain amount of bakuchiol and baicalin indicates that they can perform a synergism function,which can significantly enhance the anti-acne bacterial effects,revealing the necessity and rationality on the inhibition against staphylococcus epidermidis and propionibacterium acnes growth.
The hydrophilic property of PE non-woven thin film was improved by using sulphuration.The effect of time,temperature and the ratio of reactants on the property of hydrophilic of PE were illustrated in detail.The introduction of —(SO_3H) to sulphurated PE was characterized by(FT-IR) spectroscopy and energy dispersive X-ray(EDS).The result shows that not only the hydrophilic property of PE non-woven film is dramatically improved but also the original stretch intensity of PE non-woven film well retained when the sulphuration temperature is 80 ℃ and time is 1.5 h.
Objective: To prepare bakuchiol-baicalin compound microemulsions and investigate its in vitro transdermal diffusion characteristics. Method: With ethyl oleate as oil phase,tween-80 as emulsifier and polyethylene glycol-400( PEG-400) as co-emulsifier,aqueous phase was gradually added into mixture containing drug to produce bakuchiol-baicalin compound microemulsions. Morphology,particle size distribution and stability were characterized. Transdermal characteristics of bakuchiol and baicalin in solution and microemulsions were studied by modified Franze diffusion cell. Result: Clear and transparent microemulsion were prepared,they were showed nearly spherical under transmission electron microscope,particle size was( 17. 30 ± 0. 17) nm with excellent stability. Cumulative permeation amounts of baicalin in solution and microemulsions were( 208. 80 ±5. 26) μg·cm- 2and( 232. 38 ± 15. 07) μg ·cm- 2in 24 h, there were no significant difference of their transdermal characteristics. Cumulative permeation amounts of bakuchiol in solution and microemulsions were( 324. 81 ±56.63) μg·cm- 2and( 721. 30 ± 108. 88) μg·cm- 2in 24 h,compared with steady-state infiltration rate and apparent permeability coefficient in solution,these two parameters 5. 0 times significantly improved.Conclusion: Delivery system of microemulsions can significantly improve percutaneous absorption. This study provides experimental foundations for development of a new preparation of bakuchiol-baicalin compound skin delivery system.
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