51
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Seeni Meera KM, Murali Sankar R, Paul J, Jaisankar SN, Mandal AB. The influence of applied silica nanoparticles on a bio-renewable castor oil based polyurethane nanocomposite and its physicochemical properties. Phys Chem Chem Phys 2014; 16:9276-88. [DOI: 10.1039/c4cp00516c] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bio-renewable castor oil polyurethane–silica nanocomposite films with improved thermal, surface and mechanical properties were prepared. These films find application in biomaterials development.
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Affiliation(s)
- Kamal Mohamed Seeni Meera
- Polymer Division
- Council of Scientific and Industrial Research (CSIR) – Central Leather Research Institute (CLRI)
- Chennai 600020, India
| | - Rajavelu Murali Sankar
- Polymer Division
- Council of Scientific and Industrial Research (CSIR) – Central Leather Research Institute (CLRI)
- Chennai 600020, India
| | - Jaya Paul
- Polymer Division
- Council of Scientific and Industrial Research (CSIR) – Central Leather Research Institute (CLRI)
- Chennai 600020, India
| | - Sellamuthu N. Jaisankar
- Polymer Division
- Council of Scientific and Industrial Research (CSIR) – Central Leather Research Institute (CLRI)
- Chennai 600020, India
| | - Asit Baran Mandal
- Polymer Division
- Council of Scientific and Industrial Research (CSIR) – Central Leather Research Institute (CLRI)
- Chennai 600020, India
- Chemical Laboratory
- Council of Scientific and Industrial Research (CSIR) – Central Leather Research Institute (CLRI)
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52
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Chernev BS, Hirschl C, Eder GC. Non-destructive determination of ethylene vinyl acetate cross-linking in photovoltaic (PV) modules by Raman spectroscopy. APPLIED SPECTROSCOPY 2013; 67:1296-1301. [PMID: 24160881 DOI: 10.1366/13-07085] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Vibrational spectroscopy was found to be a suitable method for the determination of the degree of cross-linking of ethylene vinyl acetate (EVA) polymers. Spectral changes in the Raman spectra of EVA with increasing lamination time (which equals increasing degree of cross-linking) were mainly detected in the CH vibrational regions, namely, in the relative intensities of the characteristic CH3 and CH2 bands. These spectral regions were chosen for a chemometric evaluation where a calibration was performed with the Raman spectra of reference EVA samples and the results obtained from corresponding thermal analysis (differential scanning calorimetry) and Soxhlet extraction data. These datasets were subsequently used to non-destructively determine the progress of cross-linking in EVA foils, embedded in various mini-modules by Raman microscopy. Thus, we could show that Raman spectroscopy is a highly interesting method for quality control in the production of photovoltaic (PV) modules. However, this approach is valid only for a given grade of EVA, meaning a demand for a new calibration when changing the supplier or the type of EVA used. In addition, the applicability of infrared spectroscopy for the determination of the degree of cross-linking was tested. A good correlation of the decrease in intensity of the characteristic cross-linker infrared bands with increasing progress of the cross-linking was found, as determined by reference methods. However, this analytical method requires taking samples of the EVA foils and is, thus, unsuitable for the non-destructive determination of the degree of cross-linking of the EVA encapsulated within a PV module.
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Affiliation(s)
- Boril S Chernev
- Graz Centre for Electron Microscopy and Research Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, 8010 Graz, Austria
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53
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Liu H, Zhou J, Liu X, Zuo D, Gu S, Xu W. Silk-inspired polyurethane containing GlyAlaGlyAla tetrapeptide. II. physical properties and structure. J Appl Polym Sci 2013. [DOI: 10.1002/app.39185] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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54
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Andronescu C, Bîru EI, Radu IC, Gârea SA, Iovu H. Kinetics of benzoxazine polymerization studied by Raman spectroscopy. HIGH PERFORM POLYM 2013. [DOI: 10.1177/0954008313477667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Raman spectroscopy was used to monitor the curing process of a benzoxazine monomer. The reaction follows an autocatalytic mechanism. The autocatalytic model described in Kamal equation was employed. The activation energy and the pre-exponential factor were determined as: Ea = 60.52 kJ mol−1 and A = 6.09 × 105 min−1. The overall reaction order was found to be 1.731 ( n = 1.078; m = 0.653). The kinetic model characterized by these values is in good agreement with the experimental values.
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Affiliation(s)
- Corina Andronescu
- Advanced Polymer Materials Group, University “Politehnica” of Bucharest, Bucharest, Romania
| | - Elena Iuliana Bîru
- Advanced Polymer Materials Group, University “Politehnica” of Bucharest, Bucharest, Romania
| | - Ionuţ Cristian Radu
- Advanced Polymer Materials Group, University “Politehnica” of Bucharest, Bucharest, Romania
| | - Sorina Alexandra Gârea
- Advanced Polymer Materials Group, University “Politehnica” of Bucharest, Bucharest, Romania
| | - Horia Iovu
- Advanced Polymer Materials Group, University “Politehnica” of Bucharest, Bucharest, Romania
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55
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Page JM, Prieto EM, Dumas JE, Zienkiewicz KJ, Wenke JC, Brown-Baer P, Guelcher SA. Biocompatibility and chemical reaction kinetics of injectable, settable polyurethane/allograft bone biocomposites. Acta Biomater 2012; 8:4405-16. [PMID: 22871639 DOI: 10.1016/j.actbio.2012.07.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 07/13/2012] [Accepted: 07/24/2012] [Indexed: 12/11/2022]
Abstract
Injectable and settable bone grafts offer significant advantages over pre-formed implants due to their ability to be administered using minimally invasive techniques and to conform to the shape of the defect. However, injectable biomaterials present biocompatibility challenges due to the potential toxicity and ultimate fate of reactive components that are not incorporated in the final cured product. In this study the effects of stoichiometry and triethylenediamine (TEDA) catalyst concentration on the reactivity, injectability, and biocompatibility of two component lysine-derived polyurethane (PUR) biocomposites were investigated. Rate constants were measured for the reactions of water (a blowing agent resulting in the generation of pores), polyester triol, dipropylene glycol (DPG), and allograft bone particles with the isocyanate-terminated prepolymer using an in situ attenuated total reflection Fourier transform infrared spectroscopy technique. Based on the measured rate constants, a kinetic model predicting the conversion of each component with time was developed. Despite the fact that TEDA is a well-known urethane gelling catalyst, it was found to preferentially catalyze the blowing reaction with water relative to the gelling reactions by a ratio >17:1. Thus the kinetic model predicted that the prepolymer and water proceeded to full conversion, while the conversions of polyester triol and DPG were <70% after 24h, which was consistent with leaching experiments showing that only non-cytotoxic polyester triol and DPG were released from the reactive PUR at early time points. The PUR biocomposite supported cellular infiltration and remodeling in femoral condyle defects in rabbits at 8weeks, and there was no evidence of an adverse inflammatory response induced by unreacted components from the biocomposite or degradation products from the cured polymer. Taken together, these data underscore the utility of the kinetic model in predicting the biocompatibility of reactive biomaterials.
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Affiliation(s)
- Jonathan M Page
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA
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56
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Weakley AT, Warwick PCT, Bitterwolf TE, Aston DE. Multivariate analysis of micro-Raman spectra of thermoplastic polyurethane blends using principal component analysis and principal component regression. APPLIED SPECTROSCOPY 2012; 66:1269-1278. [PMID: 23146182 DOI: 10.1366/12-06588] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Probing the specific hydrogen-bonding behavior of thermoplastic polyurethane (TPU) blends using vibrational spectroscopies remains the sin qua non for understanding the link between hydrogen-bonding and phase-segregation behavior. However, current literature holds to more traditional univariate approaches when studying the morphologically interesting normal molecular vibrations of TPUs. In the present study, multivariate analysis, including principal component analysis (PCA) and principal component regression (PCR), is used to scrutinize the relevant Raman bands acquired from a binary mixture of analogous TPU copolymer blends. Considering the near identical behavior of selected spectral regions, PCA was capable of isolating linear and nonlinear composition-dependent trends on PC-scores plots. From here, the PC scores, extracted from wavelengths comprising the carbonyl stretching region (1681-1764 cm(-1)), CH(2) deformations (1380-1500 cm(-1)), aromatic stretch from the hard segment (1617 cm(-1)), and amide II mixed band (1540 cm(-1)), were used to explicitly predict the mole fraction of hard segment present in each blend using PCR. Spectral preprocessing, wavelength selection, and variable scaling were major factors in PCR accurately predicting the weight fraction of each copolymer in spite of the clearly evident, blend-specific spectroscopic behavior.
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Affiliation(s)
- Andrew Todd Weakley
- Department of Chemical and Materials Engineering, University of Idaho, Moscow, 83844-1021, USA
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57
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Sankar RM, Meera KS, Mandal AB, Jaisankar SN. Thermoplastic polyurethane/single-walled carbon nanotube composites with low electrical resistance surfaces. HIGH PERFORM POLYM 2012. [DOI: 10.1177/0954008312459545] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Thermoplastic polyurethane (TPU)/single-walled carbon nanotube (SWCNT) nanocomposite films were prepared using 1,6-hexane diisocyanate and hydroxyl-terminated polybutadiene (HTPB) in tetrahydrofuran with various concentrations of SWCNTs. The interaction between polyurethane (PU) and SWCNTs in nanocomposite was studied using different methods. The film turns yellowish to grayish-black in colour upon increasing the concentration of SWCNTs in PU matrix. This may be due to the formation of π–π interaction between polyurethane amide functional group and SWCNTs. Differential scanning calorimetric results show that the soft segment of nanocomposite interacts much stronger than hard segment, which results in lowering melting transition temperature of soft segments. The activation energy and thermal stability parameters were determined from thermogravimetric and differential scanning calorimetric analyses. The x-ray photoelectron spectroscopic results show the intermolecular interaction between HTPB-based PU and SWCNT. Mesoporous morphology of the nanocomposites was observed by scanning electron microscopy. The average diameter of the pores was calculated using Gaussian method. The TPU films exhibit about 3.5 times greater resistivity than nanocomposite films. All the analysed data prove that the SWCNTs were well distributed in PU matrix and exhibited as tough films with low electrical resistivity.
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Affiliation(s)
- R. Murali Sankar
- Polymer Division, Council of Scientific and Industrial Research (CSIR) - Central Leather Research Institute (CLRI), Adyar, Chennai, India
| | - K. Seeni Meera
- Polymer Division, Council of Scientific and Industrial Research (CSIR) - Central Leather Research Institute (CLRI), Adyar, Chennai, India
| | - Asit Baran Mandal
- Polymer Division, Council of Scientific and Industrial Research (CSIR) - Central Leather Research Institute (CLRI), Adyar, Chennai, India
| | - S. N. Jaisankar
- Polymer Division, Council of Scientific and Industrial Research (CSIR) - Central Leather Research Institute (CLRI), Adyar, Chennai, India
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58
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Wang M, Zhang X, Zhang W, Tian D, Lu C. Thermoplastic polyurethane composites prepared from mechanochemically activated waste cotton fabric and reclaimed polyurethane foam. J Appl Polym Sci 2012. [DOI: 10.1002/app.38402] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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59
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Maliger R, Halley PJ, Cooper-White JJ. Poly(glycerol-sebacate) bioelastomers-kinetics of step-growth reactions using Fourier Transform (FT)-Raman spectroscopy. J Appl Polym Sci 2012. [DOI: 10.1002/app.37719] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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60
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Roohpour N, Moshaverinia A, Wasikiewicz JM, Paul D, Wilks M, Millar M, Vadgama P. Development of bacterially resistant polyurethane for coating medical devices. Biomed Mater 2012; 7:015007. [PMID: 22287552 DOI: 10.1088/1748-6041/7/1/015007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Polyurethanes have been widely used in medicine for coating and packaging implantable and other medical devices. Polyether-urethanes, in particular, have superior mechanical properties and are biocompatible, but in common with other medical materials they are susceptible to microbial film formation. In this study, polyether-urethane was end-capped with silver lactate and silver sulfadiazine functional groups to produce a bacterially resistant polymer without sacrificing the useful mechanical properties of the polyether-polyurethane. The silver ions were covalently incorporated into the polymer during chain extension of the prepolymer. The functionalized polymers were structurally characterized by light scattering, electron microscopy, NMR, FTIR and Raman spectroscopy. Mechanical properties, hydrophilicity, in vitro stability and antibacterial action of polymers were also investigated. Results indicate that both silver salts were successfully incorporated into the polymer structure without significant effect on mechanical properties, whilst conferring acceptable bacterial resistance.
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Affiliation(s)
- Nima Roohpour
- School of Engineering and Materials Science, IRC in Biomedical Materials, Queen Mary University, London, UK.
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61
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Hunley MT, Bhangale AS, Kundu S, Johnson PM, Waters MS, Gross RA, Beers KL. In situ monitoring of enzyme-catalyzed (co)polymerizations by Raman spectroscopy. Polym Chem 2012. [DOI: 10.1039/c1py00447f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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62
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Khan AS, Hassan KR, Bukhari SF, Wong FSL, Rehman IU. Structural and in vitro adhesion analysis of a novel covalently coupled bioactive composite. J Biomed Mater Res B Appl Biomater 2011; 100:239-48. [DOI: 10.1002/jbm.b.31945] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 06/15/2011] [Accepted: 07/05/2011] [Indexed: 11/07/2022]
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63
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Dolomanova V, Rauhe JCM, Jensen LR, Pyrz R, Timmons AB. Mechanical properties and morphology of nano-reinforced rigid PU foam. J CELL PLAST 2011. [DOI: 10.1177/0021955x10392200] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study is dedicated to the investigation of the change in mechanical properties of rigid polyurethane foam reinforced with carbon nanoparticles. Pure and nano-reinforced polyurethane foams were produced by an in situ polymerization technique. Carbon nanotubes (single-walled carbon nanotubes and multi-walled carbon nanotubes) and carbon nanofibers were used as reinforcing particles. Diphenylmethane 4,4'-diisocyanate treatment of carbon nanoparticles was performed in order to improve the interaction of nanoparticles and polymer matrix. The alterations of morphology and mechanical properties of the nano-reinforced polyurethane foam were studied by varying the amount of both pristine and modified carbon nanoparticles. Compression tests revealed an improvement of both compressive Young’s modulus and compressive strength, and scanning electron microscope observations showed a decrease of the average cell size of the foam.
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Affiliation(s)
- Viktoriya Dolomanova
- Department of Mechanical and Manufacturing Engineering, Aalborg University, Pontoppidanstraede 101, 9220 Aalborg East, Denmark,
| | - Jens Chr. M. Rauhe
- Department of Mechanical and Manufacturing Engineering, Aalborg University, Pontoppidanstraede 101, 9220 Aalborg East, Denmark
| | - Lars Rosgaard Jensen
- Department of Mechanical and Manufacturing Engineering, Aalborg University, Pontoppidanstraede 101, 9220 Aalborg East, Denmark
| | - Ryszard Pyrz
- Department of Mechanical and Manufacturing Engineering, Aalborg University, Pontoppidanstraede 101, 9220 Aalborg East, Denmark
| | - Ana Barros Timmons
- Department of Chemistry, CICECO, Universidade de Aveiro, 3810-193 Aveiro, Portugal
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64
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Liu H, Xu W, Zhao S, Huang J, Yang H, Wang Y, Ouyang C. Silk-inspired polyurethane containing GlyAlaGlyAla tetrapeptide. I. Synthesis and primary structure. J Appl Polym Sci 2010. [DOI: 10.1002/app.31988] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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65
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Majoros LI, Dekeyser B, Hoogenboom R, Fijten MWM, Geeraert J, Haucourt N, Schubert US. Kinetic study of the polymerization of aromatic polyurethane prepolymers by high-throughput experimentation. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/pola.23768] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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66
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Papadopoulos E, Ginic-Markovic M, Clarke S. A thermal and rheological investigation during the complex cure of a two-component thermoset polyurethane. J Appl Polym Sci 2009. [DOI: 10.1002/app.30987] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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67
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Phong NTP, Thanh NVK, Phuong PH. Fabrication of antibacterial water filter by coating silver nanoparticles on flexible polyurethane foams. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/187/1/012079] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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68
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Roohpour N, Wasikiewicz JM, Paul D, Vadgama P, Rehman IU. Synthesis and characterisation of enhanced barrier polyurethane for encapsulation of implantable medical devices. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2009; 20:1803-1814. [PMID: 19399591 DOI: 10.1007/s10856-009-3754-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Accepted: 04/15/2009] [Indexed: 05/27/2023]
Abstract
Polymeric membranes have been used as interfaces between implantable devices and biological tissues to operate as a protective barrier from water exchanging and to enhance biocompatibility. Polyurethanes have been used as biocompatible membranes for decades. In this study, copolymers of polyether urethane (PEU) with polydimethylsiloxane (PDMS) were synthesised with the goal of creating materials with low water permeability and high elasticity. PDMS was incorporated into polymer backbone as a part of the soft segment during polyurethane synthesis and physical properties as well as water permeability of resulting copolymer were studied in regard to PDMS content. Increase in PDMS content led to increase of microphase separation of the copolymer and corresponding increase in elastic modulus. Surface energy of the polymer was decreased by incorporating PDMS compared to unmodified PEU. PDMS in copolymer formed a hydrophobic surface which caused reduction in water permeability and water uptake of the membranes. Thus, PDMS containing polyurethane with its potent water resistant properties demonstrated a great promise for use as an implantable encapsulation material.
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Affiliation(s)
- Nima Roohpour
- Interdisciplinary Research Centre in Biomedical Materials, School of Engineering and Material Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
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69
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Ho CH, Wang CH, Lin CI, Lee YD. Synthesis and characterization of (AB)n-type poly(l-lactide)–poly(dimethyl siloxane) multiblock copolymer and the effect of its macrodiol composition on urethane formation. Eur Polym J 2009. [DOI: 10.1016/j.eurpolymj.2009.04.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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70
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Philipp M, Vergnat C, Müller U, Sanctuary R, Baller J, Possart W, Alnot P, Krüger JK. Second order elasticity at hypersonic frequencies of reactive polyurethanes as seen by generalized Cauchy relations. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:035106. [PMID: 21817265 DOI: 10.1088/0953-8984/21/3/035106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The non-equilibrium process of polymerization of reactive polymers can be accompanied by transition phenomena like gelation or the chemical glass transition. The sensitivity of the mechanical properties at hypersonic frequencies-including the generalized Cauchy relation-to these transition phenomena is studied for three different polyurethanes using Brillouin spectroscopy. As for epoxies, the generalized Cauchy relation surprisingly holds true for the non-equilibrium polymerization process and for the temperature dependence of polyurethanes. Neither the sol-gel transition nor the chemical and thermal glass transitions are visible in the representation of the generalized Cauchy relation. Taking into account the new results and combining them with general considerations about the elastic properties of the isotropic state, an improved physical foundation of the generalized Cauchy relation is proposed.
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Affiliation(s)
- M Philipp
- Laboratoire de Physique des Matériaux, Université du Luxembourg, 162A, avenue de la Faïencerie, L-1511 Luxembourg, Luxembourg
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71
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Kröber P, Delaney JT, Perelaer J, Schubert US. Reactive inkjet printing of polyurethanes. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b823135d] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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72
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Khan A, Ahmed Z, Edirisinghe M, Wong F, Rehman I. Preparation and characterization of a novel bioactive restorative composite based on covalently coupled polyurethane-nanohydroxyapatite fibres. Acta Biomater 2008; 4:1275-87. [PMID: 18522875 DOI: 10.1016/j.actbio.2008.04.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2007] [Revised: 03/18/2008] [Accepted: 04/14/2008] [Indexed: 10/22/2022]
Abstract
Nanohydroxyapatite (n-HAp) was prepared using a sol-gel method. n-HAp powder was obtained from the gel form by heat treatment followed by grinding using ball milling. A novel polyurethane composite material was prepared by chemically binding the hydroxyapatite to the diisocyanate component in the polyurethane backbone through solvent polymerization. The procedure involved the stepwise addition of monomeric units of the polyurethane and optimizing the reagent concentrations. The resultant composite material was electrospun to form fibre mats. The fibres were less than 1mum in thickness and contained no beads or irregularities. Chemical structural characterization of both the ceramics and the novel polymers were carried out by Fourier transform infrared and Raman spectroscopy. X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy and Brunauer-Emmett-Teller surface area analysis were also employed to observe the crystal lattice and size and surface area of the n-HAp. Further characterization (by energy-dispersive X-ray analysis and SEM) of the spun fibres revealed the presence of elements associated with hydroxyapatite and polyurethane without the presence of any loose particles of hydroxyapatite, indicating the formation of the covalent bond between the ceramics and the polymer backbone.
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73
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Kaushik A, Singh P. Kinetic Study of Polyurethane Reaction between Castor Oil/TMP Polyol and Diphenyl Methane Diisocyanate in Bulk. INT J POLYM MATER PO 2006. [DOI: 10.1080/00914030500212248] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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74
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Xia H, Song M. Preparation and characterisation of polyurethane grafted single-walled carbon nanotubes and derived polyurethane nanocomposites. ACTA ACUST UNITED AC 2006. [DOI: 10.1039/b601152g] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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75
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Parnell S, Min K. Reaction kinetics of thermoplastic polyurethane polymerization in situ with poly(vinyl chloride). POLYMER 2005. [DOI: 10.1016/j.polymer.2005.02.110] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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76
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Li F, Zhou S, You B, Wu L. Kinetic investigations on the UV-induced photopolymerization of nanocomposites by FTIR spectroscopy. J Appl Polym Sci 2005. [DOI: 10.1002/app.22629] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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