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Zaharescu T, Mirea R, Borbath T, Borbath I. Stability Qualification of Resins/Metallic Oxide Composites for Surface Oxidative Protection. Polymers (Basel) 2024; 16:333. [PMID: 38337222 DOI: 10.3390/polym16030333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/15/2024] [Accepted: 01/23/2024] [Indexed: 02/12/2024] Open
Abstract
The accelerated degradation of alkyd resins via γ-irradiation is investigated using non-isothermal chemiluminescence. The stability qualification is possible through the comparison of emission intensities on a temperature range starting from 100 °C up to 250 °C under accelerated degradation caused by radiolysis scission. The measurements achieved in the samples of cured state resin modified by various inorganic oxides reveal the influence of metallic traces on the aging amplitude, when the thermal resistance increases as the irradiation dose is augmented. Even though the unirradiated samples present a prominent chemiluminescence intensity peak at 80 °C, the γ-processed specimens show less intense spectra under the pristine materials and the oxidation starts smoothly after 75 °C. The values of activation energies required for oxidative degradation of the sample subjected to 100 kGy are significantly higher in the composite states than in the neat resin. The degradation mechanism of polymerized resins is discussed taking into account the effects of fillers on the stability of studied epoxy resin at various temperatures when the degradation and crosslinking are in competition for the decay of free radical.
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Affiliation(s)
- Traian Zaharescu
- INCDIE-ICPE CA, Radiochemical Center, 313 Splaiul Unirii, Ro 030138 Bucharest, Romania
- ROSEAL SA, 5A Nicolae Bălcescu, Harghita District, Ro 535600 Odorheiu Secuiesc, Romania
| | - Radu Mirea
- Romanian Research and Development Institute for Gas Turbines-COMOTI, 220D Iuliu Maniu Bd., Ro 061125 Bucharest, Romania
| | - Tunde Borbath
- ROSEAL SA, 5A Nicolae Bălcescu, Harghita District, Ro 535600 Odorheiu Secuiesc, Romania
| | - Istvan Borbath
- ROSEAL SA, 5A Nicolae Bălcescu, Harghita District, Ro 535600 Odorheiu Secuiesc, Romania
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Thomaz R, Ngono-Ravache Y, Severin D, Trautmann C, Papaléo RM. Thinning of Poly(methyl methacrylate) and Poly(vinyl chloride) Thin Films Induced by High-Energy Ions of Different Stopping Powers. Polymers (Basel) 2023; 15:4471. [PMID: 38231893 PMCID: PMC10707899 DOI: 10.3390/polym15234471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 10/25/2023] [Accepted: 11/01/2023] [Indexed: 01/19/2024] Open
Abstract
Ion bombardment is an important tool of materials processing, but usually leads to erosion of the surface and significant thickness reductions when thin layers are used. The growing use of polymer thin films in a variety of applications, from coatings and membranes to biomedical and electronic devices, calls for a deeper understanding of the thinning process induced by energetic ions espe-cially for very thin films. Here, thinning and surface morphology changes induced by high-energy ion bombardment in PMMA and PVC thin films were investigated, focusing on the role of the initial thickness of the films and the stopping power of the ions. We used thin films with initial thicknesses varying from 13 to 800 nm, and light and heavy ions as projectiles in the energy range of 2-2000 MeV, where the electronic stopping dominates. Thickness reductions as a function of fluence were monitored and thinning cross sections were extracted from curves. A supralinear scaling between the thinning cross sections and the electronic stopping power of the beams was observed, with a much enhanced thinning efficiency for the swift heavy ions. The scaling with the stopping power dE/dx is almost independent of the initial thickness of the films. At intermediate and large fluences, changes in the physicochemical properties of the irradiated polymers may modulate and decelerate the thinning process of the remaining film. The importance of this secondary process depends on the stopping power and the balance between erosion and the chemical transformations induced by the beam. We also observe a trend for the thinning efficiency to become larger in very thin films. Depending on the type of beam and polymer, this effect is more or less pronounced. PMMA films irradiated with 2 MeV H+ show the most systematic correlation between initial thickness and thinning cross sections, while in PVC films the initial thickness plays a minor role for all investigated beams.
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Affiliation(s)
- Raquel Thomaz
- Interdisciplinary Center of Nanoscience and Micro-Nanotechnology, School of Technology, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90619-900, RS, Brazil
- Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Porto Alegre 91501-970, RS, Brazil
| | | | - Daniel Severin
- Materials Research, GSI Helmholtz Centre, 64291 Darmstadt, Germany
| | - Christina Trautmann
- Materials Research, GSI Helmholtz Centre, 64291 Darmstadt, Germany
- Department of Materials- and Geosciences, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Ricardo M. Papaléo
- Interdisciplinary Center of Nanoscience and Micro-Nanotechnology, School of Technology, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90619-900, RS, Brazil
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Zaharescu T, Nicula N, Râpă M, Iordoc M, Tsakiris V, Marinescu VE. Structural Insights into LDPE/UHMWPE Blends Processed by γ-Irradiation. Polymers (Basel) 2023; 15:polym15030696. [PMID: 36771997 PMCID: PMC9920361 DOI: 10.3390/polym15030696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/19/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023] Open
Abstract
Ultra-high-molecular-weight polyethylene (UHMWPE) matrices containing low-density polyethylene (LDPE), hydroxyapatite (HAp) as filler, and rosemary extract (RM) as stabilizer were investigated for their qualification for long-term applications. The significant contributions of the blend components were analyzed, and variations in mechanical properties, oxidation strength, thermal behavior, crystallinity, and wettability were discussed. SEM images of microstructural peculiarities completed the introspective survey. The stability improvement due to the presence of both additives was an increase in the total degradation period of 67% in comparison with an unmodified HDPE/UHMWPE blend when the materials were subjected to a 50 kGy γ-dose. There was growth in activation energies from 121 kJ mol-1 to 139 kJ mol-1 when HAp and rosemary extract delayed oxidation. The exposure of samples to the action of γ-rays was found to be a proper procedure for accomplishing accelerated oxidative degradation. The presence of rosemary extract and HAp powder significantly increased the thermal and oxidation resistances. The calculation of material lifetimes at various temperatures provided meaningful information on the wearability and integrity of the inspected composites.
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Affiliation(s)
- Traian Zaharescu
- INCDIE ICPE CA, 3131 Splaiul Unirii, 030138 Bucharest, Romania
- Correspondence: (T.Z.); (N.N.)
| | - Nicoleta Nicula
- INCDIE ICPE CA, 3131 Splaiul Unirii, 030138 Bucharest, Romania
- Correspondence: (T.Z.); (N.N.)
| | - Maria Râpă
- Faculty of Materials Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania
| | - Mihai Iordoc
- INCDIE ICPE CA, 3131 Splaiul Unirii, 030138 Bucharest, Romania
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Radiation Processing of Styrene-isoprene-styrene/Poly(ε-caprolactone) Blends. Polymers (Basel) 2022; 14:polym14214737. [DOI: 10.3390/polym14214737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 10/28/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
The irradiation consequences on styrene-isoprene-styrene (SIS)/poly(ε-caprolactone) (PCL) blends are discussed starting from the oxidation initiation. Three characterization methods: chemiluminescence, differential scanning calorimetry and FTIR spectroscopy are applied. The differences that exist between the two components are revealed, when the oxidation rates of the inspected formulas depend on the blending proportion and the degradation conditions. The relevant activation energies characterizing the oxidation strength as well as the kinetic parameters of degradation during the accelerated damaging of blended polymers are related to the inhibition protection of PCL on the faster oxidation of SIS. The interaction between mixed components is revealed by the structural modifications simultaneously accompanied by the competition of formation and decay of radicals.
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Massoud A, Mahmoud HH. Performance appraisal of a cross-linked polymer prepared by gamma radiation for the removal of copper and its binding mechanism. INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION 2022. [DOI: 10.1080/1023666x.2022.2138136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Affiliation(s)
- Ayman Massoud
- Nuclear Chemistry Department, Hot Labs Center, Egyptian Atomic Energy Authority, Cairo, Egypt
| | - Hazem H. Mahmoud
- Central Lab. for Elemental and Isotopes Analysis, NRC, Egyptian Atomic Energy Authority, Cairo, Egypt
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El-Khatib AM, Abbas MI, Hammoury SI, Gouda MM, Zard K, Elsafi M. Effect of PbO-nanoparticles on dimethyl polysiloxane for use in radiation shielding applications. Sci Rep 2022; 12:15722. [PMID: 36127499 PMCID: PMC9489703 DOI: 10.1038/s41598-022-20103-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 09/08/2022] [Indexed: 11/09/2022] Open
Abstract
In this work, morphological and attenuation parameters of gamma ray protection were studied. Dimethyl polysiloxane (Silicon Rubber) Mixed with micro-size and nano-size lead oxide particles at different weight percentage were prepared. The morphological structure of PbO/SR composites was investigated by SEM test, according to SEM images the nano PbO particles are more uniform micro PbO particles. The radiation attenuation test was carried out using 3" × 3" NaI (TI) detector for (Am-241), (Cs-137), (Co-60), (Ba-133), and (Eu-152). The effect on attenuation property of SR-PbO shown that the increase of PbO filler significantly increases the linear attenuation coefficient and improve the other radiation protection parameters especially at low gamma energy. It's found that a significant agreement between the experimental result and theoretical result from Xcom program. In this study it's found matrix filled with nano-PbO have higher gamma shielding ability compared to micro-PbO matrix at the same filler concentration. It can say that SR-nano PbO has a higher radiation protection than SR-micro PbO compositions.
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Affiliation(s)
- Ahmed M El-Khatib
- Physics Department, Faculty of Science, Alexandria University, Alexandria, 21511, Egypt
| | - Mahmoud I Abbas
- Physics Department, Faculty of Science, Alexandria University, Alexandria, 21511, Egypt
| | - Sabbah I Hammoury
- Head of Medical Physics and Radiotherapy Department, Alexandria Ayadi Almostakbal Oncology Hospital, Alexandria, Egypt
| | - Mona M Gouda
- Physics Department, Faculty of Science, Alexandria University, Alexandria, 21511, Egypt
| | - Kareman Zard
- Head of Medical Physics and Radiotherapy Department, Alexandria Ayadi Almostakbal Oncology Hospital, Alexandria, Egypt
| | - Mohamed Elsafi
- Physics Department, Faculty of Science, Alexandria University, Alexandria, 21511, Egypt.
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Lupu (Luchian) AM, Mariş M, Zaharescu T, Marinescu VE, Iovu H. Stability Study of the Irradiated Poly(lactic acid)/Styrene Isoprene Styrene Reinforced with Silica Nanoparticles. MATERIALS (BASEL, SWITZERLAND) 2022; 15:5080. [PMID: 35888545 PMCID: PMC9319368 DOI: 10.3390/ma15145080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 07/04/2022] [Accepted: 07/12/2022] [Indexed: 11/16/2022]
Abstract
In this paper, the stability improvement of poly(lactic acid) (PLA)/styrene-isoprene block copolymer (SIS) loaded with silica nanoparticles is characterized. The protection efficiency in the material of thermal stability is mainly studied by means of high accurate isothermal and nonisothermal chemiluminescence procedures. The oxidation induction times obtained in the isothermal CL determinations increase from 45 min to 312 min as the polymer is free of silica or the filler loading is about 10%, respectively. The nonisothermal measurements reveal the values of onset oxidation temperatures with about 15% when the concentration of SiO2 particles is enhanced from none to 10%. The curing assay and Charlesby-Pinner representation as well as the modifications that occurred in the FTIR carbonyl band at 1745 cm-1 are appropriate proofs for the delay of oxidation in hybrid samples. The improved efficiency of silica during the accelerated degradation of PLA/SIS 30/n-SiO2 composites is demonstrated by means of the increased values of activation energy in correlation with the augmentation of silica loading. While the pristine material is modified by the addition of 10% silica nanoparticles, the activation energy grows from 55 kJ mol-1 to 74 kJ mol-1 for nonirradiated samples and from 47 kJ mol-1 to 76 kJ mol-1 for γ-processed material at 25 kGy. The stabilizer features are associated with silica nanoparticles due to the protection of fragments generated by the scission of hydrocarbon structure of SIS, the minor component, whose degradation fragments are early converted into hydroperoxides rather than influencing depolymerization in the PLA phase. The reduction of the transmission values concerning the growing reinforcement is evidence of the capacity of SiO2 to minimize the changes in polymers subjected to high energy sterilization. The silica loading of 10 wt% may be considered a proper solution for attaining an extended lifespan under the accelerated degradation caused by the intense transfer of energy, such as radiation processing on the polymer hybrid.
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Affiliation(s)
- Ana Maria Lupu (Luchian)
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (A.M.L.); (H.I.)
- Extreme Light Infrastructure-Nuclear Physics (ELI-NP), Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), 077125 Magurele, Romania
| | - Marius Mariş
- Dental Medicine Faculty, University Titu Maiorescu, 22 Dâmbovnicului Tineretului St., 040441 Bucharest, Romania
| | - Traian Zaharescu
- INCDIE ICPE CA, Radiochemistry Center, 313 Splaiul Unirii, 030138 Bucharest, Romania;
| | | | - Horia Iovu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (A.M.L.); (H.I.)
- Academy of Romanian Scientists, 050094 Bucharest, Romania
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El-Khatib AM, Shalaby TI, Antar A, Elsafi M. Experimental Study of Polypropylene with Additives of Bi 2O 3 Nanoparticles as Radiation-Shielding Materials. Polymers (Basel) 2022; 14:polym14112253. [PMID: 35683923 PMCID: PMC9182889 DOI: 10.3390/polym14112253] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 05/26/2022] [Accepted: 05/28/2022] [Indexed: 01/12/2023] Open
Abstract
This work aimed to intensively study polypropylene samples (PP) embedded with micro- and nanoparticles of Bi2O3 for their application in radiation shielding. Samples were prepared by adding 10%, 20%, 30%, 40%, and 50% of Bi2O3 microparticles (mBi2O3) by weight, and adding 10% and 50% of Bi2O3 nanoparticles (nBi2O3), in addition to the control sample (pure polypropylene). The morphology of the prepared samples was tested, and also, the shielding efficiency of gamma rays was tested for different sources with different energies. The experimental LAC were determined using a NaI scintillation detector, the experimental results were compared with NIST-XCOM results, and a good agreement was noticed. The LAC values have been used to calculate some specific parameters, such as half value layer (HVL), mean free path (MFP), tenth value layer (TVL), and radiation protection efficiency (RPE), which are useful for discussing the shielding capabilities of gamma rays. The results of the shielding parameters show that the PP embedded with nBi2O3 gives better attenuation than its counterpart, PP embedded with mBi2O3, at all studied energies.
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Affiliation(s)
- Ahmed M. El-Khatib
- Physics Department, Faculty of Science, Alexandria University, Alexandria 21511, Egypt;
| | - Thanaa I. Shalaby
- Department of Medical Biophysics, Medical Research Institute, Alexandria University, Alexandria 21561, Egypt; (T.I.S.); (A.A.)
| | - Ali Antar
- Department of Medical Biophysics, Medical Research Institute, Alexandria University, Alexandria 21561, Egypt; (T.I.S.); (A.A.)
| | - Mohamed Elsafi
- Physics Department, Faculty of Science, Alexandria University, Alexandria 21511, Egypt;
- Correspondence:
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Irradiation Effects in Polymer Composites for Their Conversion into Hybrids. JOURNAL OF COMPOSITES SCIENCE 2022. [DOI: 10.3390/jcs6040109] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In this paper several aspects of profound modifications caused by high energy exposures are presented as possible candidates for the efficient adjusting processing of polymer materials. The class of hybrid composites receives special attention due to the large spectrum of formulations, where the interphase interaction decisively influences the material properties. They represent potential start points for the intimate uniformity of hybrid morphologies. Their radiation processing turns composites onto hybrid morphology with expected features, because the transferred energy is spent for the modification of components and for their compatibility. The essential changes achieved in radiation processed composites explain the new material behavior and durability based on the peculiar restructuring of polymer molecules that occurred in the polymer phase. During high energy irradiation, the interaction between intermediates born in the constitutive phases may convert the primary composites into hybrids, integrating them into large applicability spheres. During the radiation exposure, the resulting hybrids gain a continuous dispersion by means of new chemical bonds. This type of compounds achieves some specific structural modifications in the polymer phase, becoming stable hybrid composites. The functional properties of hybrids definitely influence the material behavior due to the molecular changes based on the structural reasons. The radiolysis of the vulnerable component becomes an appropriate opportunity for the creation of new material with improved stability. The radiation treatment is a proper conversion procedure by which common mixtures may become continuously reorganized. This review presents several examples for the radiation modifications induced by radiation exposure that allow the compatibilization and binding of components as well as the creation of new structures with improved properties. This approach provides the reference patterns for the extension of radiation processing over the well-conducted adjustments of polymer composites, when certain material features are compulsorily required. From this review, several solutions for the adjustment of regular polymer composites into hybrid systems may become conceivable by the extended radiation processing.
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