Modification of Bisphenol A Dicyanate Ester Resin with Poly Vinyl Pyrrolidone (K30)

2011 ◽  
Vol 217-218 ◽  
pp. 1497-1503
Author(s):  
Jie Liang Wang ◽  
Ai Juan Gu ◽  
Guo Zheng Liang
Keyword(s):  
Bisphenol A ◽  
Gelation Time ◽  
Vinyl Pyrrolidone ◽  
Infrared Spectrometry ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Mass Fractions ◽  
Low Mass ◽  
Poly Vinyl Pyrrolidone ◽  
Pvp K30

Poly vinyl pyrrolidone (PVP(K30)) / Bisphenol A Dicyanate ester (BADCy) blends were fabricated to increase the toughness of BADCy by blending processing in this paper. Curing parameters were determined by gelation time curves and differential scanning calorimetry (DSC) of the systems. Fourier transform infrared spectrometry (FTIR) and DSC data were employed to show the curing behavior and kinetics of the systems. Mechanical properties of the cured resin had been improved rapidly with the increasing of PVP(K30) at low mass fraction, but would decrease when mass fractions of PVP(K30) were higher than 15%. Scanning electron micrograph (SEM) was applied to show the microstructures of the cured matrixes. Based on the thermogravimetric analysis (TGA) curves, water absorption curves, SEM images and dielectric properties of the blends, it can be concluded that the addition of PVP(K30) can improve the toughness of BADCy greatly with little loss of other properties.

scholarly journals PREPARATION AND CHARACTERIZATION OF POLY (VINYL ALCOHOL)–POLY (VINYL PYRROLIDONE) MUCOADHESIVE BUCCAL PATCHES FOR DELIVERY OF LIDOCAINE HCL

2018 ◽  
Vol 10 (1) ◽  
pp. 115 ◽  
Author(s):  
Napaphak Jaipakdee ◽  
Thaned Pongjanyakul ◽  
Ekapol Limpongsa
Keyword(s):  
Vinyl Alcohol ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Casting Technique ◽  
In Vitro Permeation ◽  
Lidocaine Hcl ◽  
Poly Vinyl Pyrrolidone

Objective: The objectives of this study were to prepare and characterize a buccal mucoadhesive patch using poly (vinyl alcohol) (PVA), poly (vinyl pyrrolidone) (PVP) as a mucoadhesive matrix, Eudragit S100 as a backing layer, and lidocaine HCl as a model drug.Methods: Lidocaine HCl buccal patches were prepared using double casting technique. Molecular interactions in the polymer matrices were studied using attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and X-ray diffractometry. Mechanical and mucoadhesive properties were measured using texture analyzer. In vitro permeation of lidocaine HCl from the patch was conducted using Franz diffusion cell.Results: Both of the free and lidocaine HCl patches were smooth and transparent, with good flexibility and strength. ATR-FTIR, DSC and X-ray diffractometry studies confirmed the interaction of PVA and PVP. Mechanical properties of matrices containing 60% PVP were significantly lower than those containing 20% PVP (*P<0.05). Mucoadhesive properties had a tendency to decrease with the concentration of PVP in the patch. The patch containing 60% PVP had significantly lower muco-adhesiveness than those containing 20% PVP (*P<0.05). In vitro permeation revealed that the pattern of lidocaine HCl permeation started with an initial fast permeation, followed by a slower permeation rate. The initial permeation fluxes follow the zero-order model of which rate was not affected by the PVP concentrations in the PVA/PVP matrix.Conclusion: Mucoadhesive buccal patches fabricated with PVA/PVP were successfully prepared. Incorporation of PVP in PVA/PVP matrix affected the strength of polymeric matrix and mucoadhesive property of patches.

scholarly journals Semi-Interpenetrating Polymer Networks Based on Cyanate Ester and Highly Soluble Thermoplastic Polyimide

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 862 ◽  
Author(s):  
Jingfeng Liu ◽  
Weifeng Fan ◽  
Gewu Lu ◽  
Defeng Zhou ◽  
Zhen Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Elevated Temperatures ◽  
Polymer Networks ◽  
Gelation Time ◽  
Interpenetrating Polymer Networks ◽  
Step Method ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Biphenyltetracarboxylic Dianhydride ◽  
The Impact

Thermoplastic polyimide (TPI) was synthesized via a traditional one-step method using 2,3,3′,4′-biphenyltetracarboxylic dianhydride (3,4′-BPDA), 4,4′-oxydianiline (4,4′-ODA), and 2,2′-bis(trifluoromethyl)benzidine (TFMB) as the monomers. A series of semi-interpenetrating polymer networks (semi-IPNs) were produced by dissolving TPI in bisphenol A dicyanate (BADCy), followed by curing at elevated temperatures. The curing reactions of BADCy were accelerated by TPI in the blends, reflected by lower curing temperatures and shorter gelation time determined by differential scanning calorimetry (DSC) and rheological measurements. As evidenced by scanning electron microscopy (SEM) images, phase separation occurred and continuous TPI phases were formed in semi-IPNs with a TPI content of 15% and 20%. The properties of semi-IPNs were systematically investigated according to their glass transition temperatures (Tg), thermo-oxidative stability, and dielectric and mechanical properties. The results revealed that these semi-IPNs possessed improved mechanical and dielectric properties compared with pure polycyanurate. Notably, the impact strength of semi-IPNs was 47%–320% greater than that of polycyanurate. Meanwhile, semi-IPNs maintained comparable or even slightly higher thermal resistance in comparison with polycyanurate. The favorable processability and material properties make TPI/BADCy blends promising matrix resins for high-performance composites and adhesives.

scholarly journals Formulation and Characterization of Aceclofenac-Loaded Nanofiber Based Orally Dissolving Webs

Pharmaceutics ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 417 ◽  
Author(s):  
Emese Sipos ◽  
Nóra Kósa ◽  
Adrienn Kazsoki ◽  
Zoltán-István Szabó ◽  
Romána Zelkó
Keyword(s):  
Oral Absorption ◽  
Vinyl Pyrrolidone ◽  
Drug Dissolution ◽  
In Vitro Dissolution ◽  
Drug Release Profile ◽  
Scanning Calorimetry ◽  
Ft Ir ◽  
Fast Dissolution ◽  
Poly Vinyl Pyrrolidone

Aceclofenac-loaded poly(vinyl-pyrrolidone)-based nanofiber formulations were prepared by electrospinning to obtain drug-loaded orally disintegrating webs to enhance the solubility and dissolution rate of the poorly soluble anti-inflammatory active that belongs to the BCS Class-II. Triethanolamine-containing ternary composite of aceclofenac-poly(vinyl-pyrrolidone) nanofibers were formulated to exert the synergistic effect on the drug-dissolution improvement. The composition and the electrospinning parameters were changed to select the fibrous sample of optimum fiber characteristics. To determine the morphology of the nanofibers, scanning electron microscopy was used. Fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC) were applied for the solid-state characterization of the samples, while the drug release profile was followed by the in vitro dissolution test. The nanofibrous formulations had diameters in the range of few hundred nanometers. FT-IR spectra and DSC thermograms indicated the amorphization of aceclofenac, which resulted in a rapid release of the active substance. The characteristics of the selected ternary fiber composition (10 mg/g aceclofenac, 1% w/w triethanolamine, 15% w/w PVPK90) were found to be suitable for obtaining orally dissolving webs of fast dissolution and potential oral absorption.

Facile Synthesis of NiO Nanoflowers and their Application in Water Treatment

2014 ◽  
Vol 955-959 ◽  
pp. 30-33
Author(s):  
Ling Liu ◽  
Xiao Jun Zhang ◽  
Jian Zhou Liu
Keyword(s):  
Congo Red ◽  
Vinyl Pyrrolidone ◽  
Infrared Spectrometry ◽  
Facile Synthesis ◽  
X Ray ◽  
One Step ◽  
Ft Ir ◽  
Electron Microscopes ◽  
Poly Vinyl Pyrrolidone ◽  
Scanning Electron Microscopes

A facile one-step solvothermal route was developed to synthesize NiO nanoflowers (200-300 nm in diameter) with the introduction of poly(vinyl-pyrrolidone)/stearic acid (PVP/SA) mixture. The product was characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopes (FESEM), Fourier transform infrared spectrometry (FT-IR), Thermal gravimetric analyze (TGA), and Brunauer-Emmett-Teller (BET). The mesoporous NiO nanoflowers showed an excellent adsorption capacity for organic pollutants (Congo red) from waste water (about 56 mg Congo red per g NiO).

scholarly journals Fabrication of Supercritical Antisolvent (SAS) Process-Assisted Fisetin-Encapsulated Poly (Vinyl Pyrrolidone) (PVP) Nanocomposites for Improved Anticancer Therapy

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 322 ◽  
Author(s):  
Lin-Fei Chen ◽  
Pei-Yao Xu ◽  
Chao-Ping Fu ◽  
Ranjith Kumar Kankala ◽  
Ai-Zheng Chen ◽  
...  
Keyword(s):  
Pharmaceutical Formulations ◽  
Vinyl Pyrrolidone ◽  
Solution Flow Rate ◽  
Therapeutic Effects ◽  
Mass Ratio ◽  
Scanning Calorimetry ◽  
Solution Flow ◽  
Supercritical Antisolvent ◽  
Poly Vinyl Pyrrolidone

Due to its hydrophobicity, fisetin (FIS) often suffers from several limitations in terms of its applicability during the fabrication of pharmaceutical formulations. To overcome this intrinsic limitation of hydrophobicity, we demonstrate here the generation of poly (vinyl pyrrolidone) (PVP)-encapsulated FIS nanoparticles (FIS-PVP NPs) utilizing a supercritical antisolvent (SAS) method to enhance its aqueous solubility and substantial therapeutic effects. In this context, the effects of various processing and formulation parameters, including the solvent/antisolvent ratio, drug/polymer (FIS/PVP) mass ratio, and solution flow rate, on the eventual particle size as well as on distribution were investigated using a 23 factorial experimental design. Notably, the FIS/PVP mass ratio significantly affected the morphological attributes of the resultant particles. Initially, the designed constructs were characterized systematically using various techniques (e.g., chemical functionalities were examined with Fourier-transform infrared (FTIR) spectroscopy, and physical states were examined with X-ray diffraction analysis (XRD) and differential scanning calorimetry (DSC) techniques). In addition, drug release as well as cytotoxicity evaluations in vitro indicated that the nanosized polymer-coated particles showed augmented performance efficiency compared to the free drug, which was attributable to the improvement in the dissolution rate of the FIS-PVP NPs due to their small size, facilitating a higher surface area over the raw form of FIS. Our findings show that the designed SAS process-assisted nanoconstructs with augmented bioavailability, have great potential for applications in pharmaceutics.

Analysis of the Mechanical Properties of Solvent Cast Blends of PLA/PCL

2014 ◽  
Vol 679 ◽  
pp. 50-56 ◽  
Author(s):  
Yuan Yuan Chen ◽  
Luke M. Geever ◽  
Clement L. Higginbotham ◽  
Declan M. Devine
Keyword(s):  
Mechanical Properties ◽  
Contact Angle ◽  
Tensile Test ◽  
Ductile Material ◽  
Infrared Spectrometry ◽  
Significant Shift ◽  
Scanning Calorimetry ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Mass Fractions

Polylactic acid (PLA) is the most promising material in the biodegradable category. However, brittleness and poor thermal stability restrict its application. To overcome this limitation, PLA may be blended with other biodegradable materials to tailor its properties while maintain biodegradability. In this study a series of blends of PLA and poly (ε-caprolactone) (PCL) with various mass fractions were prepared by solution method and solvent casting. Films of each blend were formed when the solvent evaporated. Subsequently, tensile test samples were punched out of the film for testing and tensile testing, Fourier transform infrared spectrometry (FTIR), Differential scanning Calorimetry (DSC) and contact angle measurements were carried out. Since PCL is a ductile material, the two materials were blended together in an effort to improve the mechanical properties. However, on thermal analysis of the blends, two individual melting peaks were observed in the DSC thermograms. Furthermore, no significant shift in peaks was observed on the FTIR spectra, and clear droplets and boundaries between two components of the blend can be observed in morphology study, all indicated the immiscibility of PLA and PCL. Tensile test showed poor mechanical properties due to the poor adhesion of the two immiscible components of the blend, and the addition of PCL did not influence the wettability of the surface of the blends as there were no significant differences in contact angle measurements.

Effect of Polyvinyl Pyrrolidone Dosage on Barium Ferrite Fibers via Electrospinning

2016 ◽  
Vol 848 ◽  
pp. 333-338
Author(s):  
Yue Guang Chen ◽  
Gui Fang Liu ◽  
Shi Jiao Wang
Keyword(s):  
Barium Ferrite ◽  
Raw Materials ◽  
Precursor Solution ◽  
Vinyl Pyrrolidone ◽  
Dimethyl Formamide ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Vibration Sample Magnetometer ◽  
Poly Vinyl Pyrrolidone ◽  
Xrd Patterns

Barium ferrite micro/nanofibers were successfully prepared via the electrospinning by using dimethyl formamide (DMF) as the solvent, poly vinyl pyrrolidone (PVP) as the spinning auxiliaries and iron nitrate and barium nitrate as raw materials. The effect of poly vinyl pyrrolidone on the structure, morphology, magnetic and microwave absorbing properties were investigated by scanning electron microscope (SEM), X-ray diffraction analysis (XRD), vibration sample magnetometer (VSM) and vector network analyzer (VNA). XRD patterns of the samples confirmed that when the additive content of PVP was up to 10%, (wt%) pure barium ferrite fibers formed under the condition of the same heat treatment. Also, the FE-SEM images showed that the morphology of the fibers improved with the increase of PVP content. Moreover, the VSM results demonstrated that the saturation magnetization can reach 54.7 emu/g when the PVP dosage is 14% (wt%) in the precursor solution.

scholarly journals Nanometer Ammonium Perchlorate and Ammonium Nitrate Prepared with 2D Network Structure via Rapid Freezing Technology

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1605 ◽  
Author(s):  
Yi Wang ◽  
Xiaolan Song ◽  
Fengsheng Li
Keyword(s):  
Thermal Decomposition ◽  
Particle Size ◽  
Ammonium Nitrate ◽  
Ammonium Perchlorate ◽  
Infrared Spectrometry ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Decomposition Products ◽  
Xrd Patterns ◽  
2D Network

Nanometer (nano) ammonium perchlorate (AP) and ammonium nitrate (AN) were prepared with 2D network structures by the ultra-low temperature spray method. Scanning electron microscopy (SEM), X-ray diffractometry (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis/infrared spectrometry (TG-IR) were employed to probe the micron structure, crystal phase, and thermal decomposition of nano AP and nano AN. SEM images revealed that the sizes of nano AP and AN were in the nanometer scale (<100 nm) in one dimension. XRD patterns showed that the crystal phases of nano AP and AN were in accordance with those of raw AP and raw AN, respectively. DSC traces indicated that the thermal decomposition process of AP depended on its particle size, while the thermolysis of AN was independent of the particle size of AN. TG-IR analyses illustrated that the decomposition products of nano AP were NO2, N2O, HCl and H2O, with a small amount of NOCl, and the main decomposition products of nano AN were N2O and H2O, with a small amount of NH3. The results of mechanical sensitivity tests indicated that nano AP was more sensitive than raw AP and both nano AN and raw AN were very insensitive to impact and friction stimuli.

scholarly journals Experimental measurements and modeling of solvent activity and surface tension of binary mixtures of polyvinylpyrrolidone in water and ethanol

2017 ◽  
Vol 82 (4) ◽  
pp. 427-435
Author(s):  
Majid Taghizadeh ◽  
Saber Amiri
Keyword(s):  
Surface Tension ◽  
Vinyl Pyrrolidone ◽  
Polymer Mixtures ◽  
Temperature Range ◽  
Molecular Weights ◽  
Activity Measurements ◽  
Mass Fractions ◽  
Eyring Model ◽  
Poly Vinyl Pyrrolidone ◽  
Solvent Activity

In this paper, the density (?), viscosity (?) and surface tension (?) of solutions of poly(vinyl pyrrolidone) (PVP) with molecular weights of 25000 (K25) and 40000 g mol-1 (K40) in water and ethanol were measured in the temperature range 20?65?C and at various mass fractions of polymer (0.1, 0.2, 0.3 and 0.45). The solvent activity measurements were performed at 45 and 55?C. Thereafter, two thermodynamic models for predicting the solvent activity and surface tension of binary polymer mixtures (PVP in water and ethanol) were proposed. The Flory?Huggins theory and Eyring model were employed to calculate the surface tension of the solution and the solvent activity, respectively. Additionally, the proposed activity model was dependent on the density and viscosity of the solution. Afterwards, the ability of these models at various temperatures and mass fractions were investigated by comparing the results with the experimental data. The results confirmed that, in the investigated temperature range, these models have good accuracy.

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