Electrospinning of Chitosan Biopolymer and Polyethylene Oxide Blends

2020 ◽  
Vol 20 (4) ◽  
pp. 426-440
Author(s):  
Sandra Varnaitė-Žuravliova ◽  
Natalja Savest ◽  
Julija Baltušnikaitė-Guzaitienė ◽  
Aušra Abraitienė ◽  
Andres Krumme
Keyword(s):  
Electrical Conductivity ◽  
Molecular Weight ◽  
Polyethylene Oxide ◽  
Synthetic Polymer ◽  
Morphological Properties ◽  
Low Molecular Weight ◽  
Fibrous Materials ◽  
Scanning Calorimetry ◽  
Electrospinning Technique ◽  
Tissue Scaffold

AbstractThe objective of this study is to investigate the morphological (scanning electron microscopicy images), thermal (differential scanning calorimetry), and electrical (conductivity) properties and to carry out compositional analysis (Fourier-transform infrared) of produced nonwoven fibrous materials adapted in biomedical applications as scaffolds. The orientation of produced nanofilaments was also investigated because it is considered as one of the essential features of a perfect tissue scaffold. Viscosity and electrical conductivity of solutions, used in the manufacturing process, were also disassembled because these properties highly influence the morphological properties of produced nanofibers. The nanofibrous scaffolds were fabricated via conventional electrospinning technique from biopolymer, synthetic polymer, and their blends. The chitosan (CS) was chosen as biopolymer and polyethylene oxide (PEO) of low molecular weight as synthetic polymer. Solutions from pure CS were unspinnable: beads instead of nanofibers were formed via spinning. The fabrication of pure PEO nanomats from solutions of 10 wt%, 15 wt%, and 20 wt% concentrations (in distilled water) turned out to be successful. The blending of composed CS solutions with PEO ones in ratios of 1:1 optimized the parameters of electrospinning process and provided the opportunity to fabricate CS/PEO blends nanofibers. The concentration of acetic acid (AA) used to dissolve CS finely spuninned the nanofibers from blended solutions and influenced the rate of crystallization of manufactured fiber mats. The concentration of PEO in solutions as well as viscosity of solutions also influenced the diameter and orientation of formed nanofibers. The beadless, highly oriented, and defect-free nanofibers from CS/PEO solutions with the highest concentration of PEO were successfully electrospinned. By varying the concentrations of AA and low molecular weight PEO, it is possible to fabricate beadless and highly oriented nanofiber scaffolds, which freely can found a place in medical applications.

Melt Processed Polymer Blends for Potential Regenerative Medicine Applications

2014 ◽  
Vol 679 ◽  
pp. 92-100
Author(s):  
Elaine Kenny ◽  
Declan M. Devine ◽  
Clement L. Higginbotham ◽  
Luke M. Geever
Keyword(s):  
Molecular Weight ◽  
Differential Scanning Calorimetry ◽  
Regenerative Medicine ◽  
Polyethylene Oxide ◽  
Melt Flow Index ◽  
Flow Index ◽  
Biodegradable Implants ◽  
Scanning Calorimetry ◽  
Breakdown Rate

There is an urgent and unmet requirement for biocompatible and biodegradable implants that gradually resorb when implanted in vivo. This study examines the potential of melt extruded thermoplastics polyethylene oxide (PEO) and polycaprolactone (PCL) in the area of regenerative medicine. Various ratios of PEO and PCL were melt blended and analysed in order to obtain an optimised breakdown rate. Subsequently the effect of varying the molecular weight of PCL using a constant molecular weight PEO was also examined. Samples were characterised using melt flow index (MFI), differential scanning calorimetry (DSC) and breakdown analysis. It was found that by altering both the concentrations of PEO/PCL and the molecular weight of PCL, melt viscosity, breakdown rate and thermal properties could be modulated to produce potential implant materials with a tailored breakdown rate.

Influence of two novel compatibilizers on the properties of LDPE/organoclay nanocomposites

2014 ◽  
Vol 34 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Haydar U. Zaman ◽  
Dalour Hossen Beg
Keyword(s):  
Molecular Weight ◽  
Tensile Modulus ◽  
Low Molecular Weight ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Nucleation Effect ◽  
Transmission Electron ◽  
Linear Viscoelastic ◽  
Silicate Clay

Abstract In the present investigation, low density polyethylene (LDPE)/organoclay nanocomposites with various clay contents (1–7 wt%) were prepared via a melt mixing technique, using two different compatibilizers with various contents; low molecular weight trimethoxysilyl-modified polybutadiene (Organosilane) and low molecular weight oxidized polyethylene (OxPE). The effects of incorporation of compatibilizers and clay contents on the mechanical and thermal properties of the nanocomposites were investigated. The dispersibility of silicate clay in the nanocomposites was investigated by transmission electron microscopy (TEM). It was found that organosilane yielded better clay dispersion and a more exfoliated structure compared with the OxPE. Rheological behavior of the samples was examined by a dynamic oscillatory rheometer in the linear viscoelastic region. The organosilane compatibilized system conferred higher tensile strength, yield strength and tensile modulus than those of an uncompatibilized system, and even higher than those of the OxPE compatibilized case. The crystallization behaviors of uncompatibilized and compatibilized nanocomposites were investigated using differential scanning calorimetry (DSC). DSC results indicated that the addition of compatibilizers increased the crystallization temperature (Tc) as a result of heterogeneous nucleation effect of clay on LDPE.

The influence of polymerization temperature on structure and properties of polyaniline

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Faris Yılmaz ◽  
Zuhal Küçükyavuz
Keyword(s):  
Thermal Analysis ◽  
Electrical Conductivity ◽  
Molecular Weight ◽  
Hydrochloric Acid ◽  
Liquid Medium ◽  
Thermal Studies ◽  
Ammonium Persulfate ◽  
Morphological Properties ◽  
Polymerization Temperature ◽  
Structure And Properties

AbstractThe influence of polymerization temperature (from -25 to +25 oC) on molecular weight, crystallinity, electrical conductivity, thermal and morphological properties of polyaniline has been investigated. Aniline was oxidized in an aqueous medium with ammonium persulfate and 1.0 M hydrochloric acid. The reaction mixture freezes below -10 oC and hence lithium chloride was used in sufficient amount to prevent freezing. As the reaction temperature decreases, both the molecular weight of polyaniline and its crystallinity increase. Thermal studies show a common three step decomposition pattern irrespective of the temperature used during synthesis. The morphology of polyaniline changes from granular (reaction in liquid medium) to tubular (polymerization in the frozen state). Thermal analysis indicated that the polyaniline stability increased with decreasing synthesis temperatures. Electrical conductivity of polyaniline was found to be independent of the polymerization temperature and, consequently, of the molecular weight.

scholarly journals Properties and structure of high temperature resistant cyanate ester/polyethersulfone blends using solvent-free toughening approach

2020 ◽  
Author(s):  
Lyaysan Amirova ◽  
Fabian Schadt ◽  
Markus Grob ◽  
Christian Brauner ◽  
Thomas Ricard ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Temperature ◽  
Network Formation ◽  
Mechanical Analysis ◽  
Solvent Free ◽  
Cyanate Ester ◽  
Low Molecular Weight ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
The Difference

AbstractA high temperature resistant novolac cyanate ester was blended with polyethersulfone (PES) with different molecular weights using the solvent-free approach. The phase separation, curing behavior and thermal properties were studied using hot stage microscopy, differential scanning calorimetry and dynamic mechanical analysis. Results showed the difference in the morphology for blends with different molecular weight PES explained by possible network formation. The influence of PES content on the glass transition temperature and mechanical properties was investigated. The most significant toughening effect (increase of 132% in fracture toughness) was achieved on a functionalized low molecular weight PES (20 parts per hundred of resin, phr). Rheology investigation allowed to estimate the optimal content of PES (15 phr) for further prepreg manufacturing.

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