A combined method of electrostatic adsorption and green reduction was successfully employed to synthesize graphene-loaded carbon nanofibers (G/CNFs). The graphene nanoflakes enhanced the degree of graphitization of CN...
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Correction for ‘Increased hydrophobic block length of PTDMs promotes protein internalization’ by Coralie M. Backlund, et al., Polym. Chem., 2016, 7, 7514–7521.
Correction for ‘Increased hydrophobic block length of PTDMs promotes protein internalization’ by Coralie M. Backlund, et al., Polym. Chem., 2016, 7, 7514–7521.
Stereoregular poly(vinyl chloride) (PVC) was prepared by solid state polymerization. Its solubility into organic solvents and the thermal properties were studied in comparison with those of ordinary free radically pre...
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Stereoregular poly(vinyl chloride) (PVC) was prepared by solid state polymerization. Its solubility into organic solvents and the thermal properties were studied in comparison with those of ordinary free radically prepared sample. Urea canal PVC was obtained in a form of white powder, which was thermally unstable as evidenced by easy discoloration in the powder state heating up to 80oC to be pale purple. In contract, free radical PVC didn't causediscoloration in the solid state under the same conditions. Easy discoloration of urea canal PVC is probably due to the absence of termination reaction, and the insolubility into organic solvents is due to the stiffness of polymer chain. An elimination reaction was studied by FT-IR and 13C NMR spectra were measured. The elimination reaction was more rapid in free radical PVC (in solution) than in urea canal one (in suspension). The resulting poyene structure -(CH=CH)n- was essentially trans-form not cis-one. 13C NMR spectra showed clearly that a large amount of polyene is formed in the free radical sample and very little in the urea canal one. Quite complexchemical inertness of the urea canal PVC was clarified in this way.
In this study, novel nylon/spandex elastomeric burn pressure garments were developed with a durable antimicrobial performance using silane and quaternary ammonium compounds (QAC's). A series of physical, mechanica...
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In this study, novel nylon/spandex elastomeric burn pressure garments were developed with a durable antimicrobial performance using silane and quaternary ammonium compounds (QAC's). A series of physical, mechanical and thermophysiological properties were tested before and after the application of the antimicrobial finish, including air permeability, stiffness, drapeability, bursting strength and extensibility, thermal resistance (Rct) and thermal insulation (in clo units). Antimicrobial tests were performed after 50 washing cycles using AATCC 100 Test Method, and they showed a 99% reduction in bacterial activity for those fabrics treated with the QAC-Silane antimicrobial agents. Physical, mechanical and thermophysiological properties were tested after antimicrobial treatments. A small significant increase was observed in terms of thermal resistance (Rct) (Tog) and isolation (It) (clo) properties for treated fabrics samples. The air permeability, bursting strength and drapeability showed a small significant decrease after antimicrobial finishing, while the elastomeric fabric showed a small but significant increase for fabric stiffness. These results confirm that when these novel pressure garments are used by burn patients, they will not only decrease the incidence of infection but will also provide comfort during prolonged use.
The microtacticity of free radically prepared poly(acrylonitrile) (PAN) has been assigned to be symndiotactic. But this is not true. Actual tacticity was atactic, as verified by the NMR procedure developed by F. Bovey...
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The microtacticity of free radically prepared poly(acrylonitrile) (PAN) has been assigned to be symndiotactic. But this is not true. Actual tacticity was atactic, as verified by the NMR procedure developed by F. Bovey (J. Polym. Sci., 1960). Wrong assignment was caused by the fabrication of NMR data published in the world-wide journal in 1960's. In one hand, we have found that syndiotactic rich PAN is obtained by solid state polymerization using Zeolites. This is the 1st case, where syndiotactic rich PAN was prepared actually, and its configuration was confirmed by 13C NMR spectra. Earlier scientific papers didn't ensure syndiotactic one. Thus, the control of microtacticity of PAN became possible by using different matrixes: Organic urea (1D-canal) ensured isotactic polymer, whereas inorganic Zeolites (3D-space) did syndiotactic one. Quite specific intermolecular interaction between polar AN and ionic center (Na+) on Zeolites surface was suggested.
Cellulose nanofiber (CNF1) as natural fiber and carbon nanofiber (CNF2) as synthetic fiber were used as reinforcement fillers in polypropylene (PP) polymer to improve the mechanical properties of the composite. The CN...
Cellulose nanofiber (CNF1) as natural fiber and carbon nanofiber (CNF2) as synthetic fiber were used as reinforcement fillers in polypropylene (PP) polymer to improve the mechanical properties of the composite. The CNF1 was produced from Kenaf bast fibers by use of mechanical method and the CNF2 was synthesized by use of chemical vapor deposition (CVD) technique. The produced fillers were dispersed into polypropylene, to manufacture nanocomposites (CNF1/PP and CNF2/PP). Analysis and comparison were made on the effects of the natural fibers with synthetics fibers having the same size and dimension, on the properties of polymer matrix. The characteristics of the CNF1 and CNF2 such as morphology, structure and composition were studied through SEM, TEM and EDX. Tensile test is used to evaluate the mechanical properties of the produced nanocomposites.
In this study, nanohydroxyapatite/polyurethane （nHA/PU） composites with various contents of methoxy- poly（ethylene glycol） modified nHA （0 wt%, 10 wt%, 20 wt% and 30 wt%） were prepared by solution blending proce...
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In this study, nanohydroxyapatite/polyurethane （nHA/PU） composites with various contents of methoxy- poly（ethylene glycol） modified nHA （0 wt%, 10 wt%, 20 wt% and 30 wt%） were prepared by solution blending process. The physicochemical properties of the composite membranes were investigated by Fourier transform infrared spectroscopy （FTIR）, X-ray diffraction （XRD）, Transmission electronic microscopy （TEM）, Differential scanning calorimetry （DSC）, Thermo gravimetric analysis （TGA） and tensile tests. TEM photos of the nanocomposites showed that the nHA was uniformly dispersed in the polymer matrix. The membrane with 10 wt% nHA showed the highest tensile strength which was about 75% higher than that of the pure PU membrane. However, the tensile strength decreased when high content （above 20 wt%） fillers were added, which was still higher than that of pure PU. TGA measurements suggested that the thermal stability of the membranes was improved owing to nHA fillers. XRD and DSC results illustrated that the crystallinity of PU soft segments decreased with the increasing content of nanoparticles in the composites.
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