Qiaochun Gao

Structure and Performance of Poly(vinyl alcohol)/Poly(γ-benzyl L-glutamate) Blend Membranes

Poly(vinyl alcohol) (PVA)/poly(γ-benzyl L-glutamate) (PBLG) blend membranes with different PBLG wt contents were prepared by pervaporation. Structure and surface morphologies of PVA/PBLG blend membranes were investigated by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of PVA/PBLG blend membrane were studied by differential scanning calorimeter (DSC), tensile strength tests, and other physical methods. It was revealed that the introduction of PBLG homopolymer into PVA could exert an outstanding effect on the properties of PVA membrane.

Properties Study of Poly(L-lactic acid)/Polyurethane-Blend Film

Poly(L-lactic acid) (PLLA)/polyurethane (PU)-blend films were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the PLLA/PU-blend films were investigated by scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of PLLA/PU-blend films were studied by differential scanning calorimetry (DSC), tensile tests, and contact angle testing. It was indicated that the addition of PU could exert marked effects on the properties of PLLA films.

Properties of Polypeptide-Based Membrane Improved by Flexible Poly(ethylene glycol)

Poly(γ-benzyl L-glutamate)/poly(ethylene glycol) (PBLG/PEG) polymer blend membranes were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the polymer blend membranes were investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Thermal and mechanical properties of the polymer blend membranes were researched using differential scanning calorimeter (DSC) and tensile tests. It was revealed that the introduction of PEG could exert outstanding effects on the morphology and the properties of the polymer blend membranes.

Modification of poly(vinyl alcohol) membrane via blending with poly(γ-benzyl l-glutamate)-block-poly(ethylene glycol) copolymer

A series of poly(vinyl alcohol) (PVA)/poly(γ-benzyl l-glutamate)-block-poly(ethylene glycol) (PBLG-b-PEG) blend membranes with different PVA/PBLG-b-PEG mole ratios were prepared by pervaporation. Structure and morphologies of PVA/PBLG-b-PEG blend membranes were investigated using Fourier transformation infrared spectroscopy (FTIR), and atomic force microscopy (AFM). Mechanical and chemical properties of PVA/PBLG-b-PEG blend membrane were studied by tensile testing and other physical methods. It was revealed that the introduction of PBLG-b-PEG copolymer has significant effect on the properties of a PVA membrane.

Poly(vinyl alcohol) Membrane Modified by Polyurethane

A series of poly(vinyl alcohol) (PVA)/polyurethane (PU) blend membranes were prepared by casting the polymer blend solution in dimethyl sulfoxide (DMSO). Structure and morphologies of PVA/PU blend membranes were investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of PVA/PU blend membrane were studied by differential scanning calorimetry (DSC), tensile tests, and surface contact angle tests. It was found that the introduction of PU could exert marked effects on the morphology and the properties of PVA membrane.

Factors influencing aggregation behavior of poly( γ -benzyl l -glutamate)- graft -poly(ethylene glycol) copolymer in mixed solvents

Poly(γ-benzyl l-glutamate)-graft-poly(ethylene glycol) (PBLG-graft-PEG) copolymer was synthesized by the ester exchange reaction of PBLG homopolymer with mPEG. Aggregation behavior of the PBLG-graft-PEG copolymer in mixtures of ethanol and chloroform was investigated by transmission electron microscopy (TEM), dynamic light scattering (DLS), and viscometry. Effects of the polymer solution concentration, grafting degree, test temperature, and chloroform content on the morphology, average particle diameter, and critical micelle concentration (CMC) of the micelles formed by the PBLG-graft-PEG copolymer in the mixed solvents were mainly studied. It was revealed that the PBLG-graft-PEG copolymer can self-assemble into polymeric micelles with a core-shell structure in various shapes depending on the preparation conditions.

Properties of poly(γ-benzyl L-glutamate) membrane modified by polyurethane containing carboxyl group

A series of poly(γ-benzyl l-glutamate) (PBLG)/polyurethane (PU) containing carboxyl group blend membranes was prepared by casting the polymer blend solution in dimethylformamide (DMF). The surface morphology of the PBLG/PU blend membranes was investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of PBLG/PU blend membranes were studied by differential scanning calorimetry (DSC), tensile tests and other physical methods. It was revealed that the introduction of PU could exert outstanding effects on the morphology and the properties of PBLG membrane.

Reaction Factors Influencing the Synthesis of Polystyrene-Polyurethane-Polystyrene Triblock Copolymer

Polystyrene-polyurethane-polystyrene (PS-PU-PS) triblock copolymer was synthesized by two-step polymerization. The first step, polyurethane (PU) prepolymers based on 2,4-toluene diisocyanate (TDI), hydrophilic poly(ethylene glycol) (PEG), hydroxyethyl acrylate (HEA), and ethylene glycol (EG), were prepared with ethylene glycol as a chain extender, dibutyltin dilaurate as a catalyst, and toluene as a solvent. The next step, polystyrene-polyurethane-polystyrene (PS-PU-PS) triblock copolymers, were prepared by free radical copolymerization between PU prepolymer and styrene (ST) monomer. Toluene and 2,2′-azobisisobutyronitrile (AIBN) were used as solvent and initiator, respectively. Fourier transform infrared spectroscopy (FT-IR) spectroscopy was used to characterize the structure of the copolymer. Influences of reaction temperature, reaction time, catalyst sorts, isocyanate monomer sorts, solvent sorts, and the concentration of initiator on the synthesis of the triblock copolymer were studied.

Properties of poly(lactic acid-co-glycolic acid) film modified by blending with polyurethane

A number of poly(lactic acid-co-glycolic acid)/polyurethane (PLGA/PU) blend films with various PU mole contents were prepared by casting the polymer blend solution in chloroform. The surface morphologies of the PLGA/PU blend films were studied by scanning electron microscopy (SEM). The thermal, mechanical and chemical properties of the PLGA/PU blend films were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile tests and surface contact angle tests. The results revealed that the introduction of PU could markedly modify the properties of PLGA films.

Modification of Hydrophobic Polypeptide-based Film by Blending with Hydrophilic Poly(acrylic acid)

In this study, a series of poly(γ-benzyl L-glutamate)/poly(acrylic acid) (PBLG/PAA) polymer blend films were prepared by casting the polymer blend solution in dimethylsulfoxide (DMSO). The structure and morphology of the polymer blend film were investigated by Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). Thermal, mechanical, and chemical properties of PBLG/PAA polymer blend films were studied by Differential Scanning Calorimetry (DSC), Thermogravimetric (TG) Analysis, Tensile Tests, and measurements of Surface Contact Angles. The results revealed that the introduction of PAA could exert great effects on the structure and properties of the polypeptide films.