Synthesis and Characterization of Polyurethane Scaffolds for Biomedical Applications

2009 ◽  
Vol 1243 ◽  
Author(s):  
M.C. Chavarría-Gaytán ◽  
I. Olivas-Armendáriz ◽  
P.E. García-Casillas ◽  
A. Martínez-Villafañe ◽  
C. A. Martínez-Pérez

ABSTRACTPolyurethanes are interesting materials that can be used in biomedical applications for regeneration of bone tissue. In this work the synthesis and characterization of porous polyurethanes to act as scaffold is performed by a thermally induced phase separation technique. The appropriate parameters are determined in order to obtain a porous well interconnected material. Characterization by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is made in order to determine the thermal stability of the material. Chemical characterization is made by Fourier transformed infrared spectroscopy with attenuated total reflectance (FTIR-ATR). The morphology of the material is observed by a field emission scanning electron microscope (FESEM) and the mechanical properties are measured by dynamic mechanical analysis (DMA).

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaowen Cui ◽  
Deyue Yan ◽  
Dan Xiao

Abstract Linear polyamides with high aliphatic content were prepared through step-heating melt polycondensation of tridecanedioic acid with various diamines. The synthesized polyamides were characterized comprehensively by means of IR, NMR and Raman spectroscopy. In addition, thermogravimetry, differential scanning calorimetry and dynamic mechanical analysis were used to investigate thermal properties of the obtained polyamides. It was found that melting and crystallization temperatures decrease as the aliphatic content increases. X-ray diffraction was applied to determine the crystal structures of the polyamides.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Abdel-Azim A. Abdel-Azim ◽  
A. Mahmoud Abdul-Raheim ◽  
Ayman Mohamady Atta ◽  
Witold Brostow ◽  
A. Fawzy El-Kafrawy

AbstractCinnamoyloxy ethyl methacrylate (CEMA) was copolymerized with different monomer feed ratios of octadecyl acrylate (ODA) and crosslinked using azobisisobutyronitrile (AIBN) as the initiator and N,N’,N”-trisacryloyl melanine (AM) or N,N’,N”,-trismethacryloylmelanine (MM) crosslinkers. The networks are characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). For crosslinked CEMA/ODA copolymer sol fraction values are lower when MM is used rather than AM. The thermal stability of crosslinked network increases with increasing ODA concentration and also in the presence of MM crosslinker, a consequence of higher crosslinking density. SEM results show a porous structure; micropores are formed when ODA contents increases. According to DMA results, the flexibility of the network is enhanced by incorporation of MM rather than AM. Since our crosslinked networks are both flexible and porous, they are applicable as oil sorber networks to alleviate pollution from oil spills.


Author(s):  
B. M. Culbertson ◽  
M. L. Devinev ◽  
E. C. Kao

The service performance of current dental composite materials, such as anterior and posterior restoratives and/or veneer cements, needs to be improved. As part of a comprehensive effort to find ways to improve such materials, we have launched a broad spectrum study of the physicochemical and mechanical properties of photopolymerizable or visible light cured (VLC) dental composites. The commercially available VLC materials being studied are shown in Table 1. A generic or neat resin VLC system is also being characterized by SEM and TEM, to more fully understand formulation variables and their effects on properties.At a recent dental research meeting, we reported on the differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) characterization of the materials in Table 1. It was shown by DSC and DMA that the materials are substantially undercured by commonly used VLC techniques. Post curing in an oral cavity or a dry environment at 37 to 50°C for 7 or more hours substantially enhances the cure of the materials.


RSC Advances ◽  
2021 ◽  
Vol 11 (16) ◽  
pp. 9076-9085
Author(s):  
Kanchan Yadav ◽  
Megha Das ◽  
Nurul Hassan ◽  
Archana Mishra ◽  
Jayeeta Lahiri ◽  
...  

A novel nanodot-using protein has been synthesized for the live cell imaging and drug delivery of melatonin in breast cancer cells. Its unique properties hold potential for various biomedical applications in the field of bioimaging and drug delivery.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Emi Govorčin Bajsić ◽  
Vesna Rek ◽  
Ivana Ćosić

The effect of the addition of talc on the morphology and thermal properties of blends of thermoplastic polyurethane (TPU) and polypropylene (PP) was investigated. The blends of TPU and PP are incompatible because of large differences in polarities between the nonpolar crystalline PP and polar TPU and high interfacial tensions. The interaction between TPU and PP can be improved by using talc as reinforcing filler. The morphology was observed by means of scanning electron microscopy (SEM). The thermal properties of the neat polymers and unfilled and talc filled TPU/PP blends were studied by using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The addition of talc in TPU/PP blends improved miscibility in all investigated TPU/T/PP blends. The DSC results for talc filled TPU/PP blends show that the degree of crystallinity increased, which is due to the nucleating effect induced by talc particles. The reason for the increased storage modulus of blends with the incorporation of talc is due to the improved interface between polymers and filler. According to TGA results, the addition of talc enhanced thermal stability. The homogeneity of the talc filled TPU/PP blends is better than unfilled TPU/PP blends.


2015 ◽  
Vol 159 ◽  
pp. 118-121 ◽  
Author(s):  
Ernandes T. Tenório-Neto ◽  
Marcos R. Guilherme ◽  
Manuel E.G. Winkler ◽  
Lucio Cardozo-Filho ◽  
Stéphani C. Beneti ◽  
...  

2021 ◽  
Vol 36 (2) ◽  
pp. 137-143
Author(s):  
S. A. Awad

Abstract This paper aims to describe the thermal, mechanical, and surface properties of a PVA/HPP blend whereby the film was prepared using a solution casting method. The improvements in thermal and mechanical properties of HPP-based PVA composites were investigated. The characterization of pure PVA and PVA composite films included tensile tests, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results of TGA and DSC indicated that the addition of HPP increased the thermal decomposition temperature of the composites. Mechanical properties are significantly improved in PVA/HPP composites. The thermal stability of the PVA composite increased with the increase of HPP filler content. The tensile strength increased from 15.74 ± 0.72 MPa to 27.54 ± 0.45 MPa and the Young’s modulus increased from 282.51 ± 20.56 MPa to 988.69 ± 42.64 MPa for the 12 wt% HPP doped sample. Dynamic mechanical analysis (DMA) revealed that at elevated temperatures, enhanced mechanical properties because of the presence of HPP was even more noticeable. Morphological observations displayed no signs of agglomeration of HPP fillers even in composites with high HPP loading.


2007 ◽  
Vol 12 (4) ◽  
pp. 574-582 ◽  
Author(s):  
Nelson Heriberto de Almeida Camargo ◽  
O. J. Bellini ◽  
Enori Gemelli ◽  
M. Tomiyama

Nanostructured materials have been largely studied in the last few years because they have a great potential to applications in different fields like physics, chemistry, biology, mechanic and medicine. Synthesis and characterization of nanostructured materials is a subject of great interest involving science, market, politicians, government and society. The nanostructured materials are in demand in biomedical area, mainly the bioceramics composed of calcium phosphates (Ca/P), which have an excellent biocompatibility and mineralogical characteristics similar to those of bones. The aim of this work was to optimize the method of powder synthesis of nanostructured calcium phosphate and of nanocomposites composed of calcium phosphate//SiO2n, containing 5, 10 and 15% (in volume) of nanometric silica (SiO2n). The results are expressed according to the method of synthesis, mineralogical and morphological characterization, and thermal behavior for the different compositions of the nanostructured powder synthesized.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Emerson C. G. Campos ◽  
Cristiano Zanlorenzi ◽  
Bruno F. Nowacki ◽  
Gabriela M. Miranda ◽  
Denis A. Turchetti ◽  
...  

This work reports the synthesis and characterization of a conjugated polymer based on fluorene and terpyridine, namely, poly[(9,9-bis(3-((S)-2-methylbutylpropanoate))fluorene-alt-6,6′-(2,2′:6′,2′′-terpyridin-6-yl)] (LaPPS71). The structure was characterized by 1H and 13C nuclear magnetic resonance (NMR) and Fourier-transform infrared (FTIR) spectroscopy. The molar mass was measured by gel permeation chromatography (GPC). As thermal characterization, the glass transition temperature (Tg) was measured by differential scanning calorimetry (DSC). The polymer structure contains two sites capable of complexation with metallic ions, affording the possibility of obtainment of independent or electronically coupled properties, depending on the complexation site. The photophysical properties were fully explored in solution and solid state, presenting ideal results for the preparation of various metallopolymers, in addition to potential application as a metamaterial, due to the presence of the chiral center in the side chains of the polymer.


MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2689-2694
Author(s):  
Karla A. Gaspar-Ovalle ◽  
Juan V. Cauich-Rodriguez ◽  
Armando Encinas

ABSTRACTNanofibrous mats of poly ε-caprolactone (PCL) were fabricated by electrospinning. The nanofiber structures were investigated and characterized by scanning electron microscope, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, static water-contact-angle analysis and mechanical properties. The results showed that the nanofibrous PCL is an ideal biopolymer for cell adhesion, owing to its biocompatibility, biodegradability, structural stability and mechanical properties. Differential scanning calorimetry results showed that the fibrous structure of PCL does not alter its crystallinity. Studies of the mechanical properties, wettability and degradability showed that the structure of the electrospun PCL improved the tensile modulus, tensile strength, wettability and biodegradability of the nanotemplates. To evaluate the nanofibrous structure of PCL on cell adhesion, osteoblasts cells were seeded on these templates. The results showed that both adhesion and proliferation of the cells is viable on these electrospun PCL membranes. Thus electrospinning is a relatively inexpensive and scalable manufacturing technique for submicron to nanometer diameter fibers, which can be of interest in the commodity industry.


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