Loading...
Search for:
gel-content
0.005 seconds
Effect of organoclay loading and electron beam irradiation on the physico-mechanical properties of low-density polyethylene/ethylene-vinyl acetate blend
, Article Polymers for Advanced Technologies ; Volume 22, Issue 12 , 2011 , Pages 2352-2359 ; 10427147 (ISSN) ; Behradfar, A ; Sheikh, N ; Sharif University of Technology
2011
Abstract
The influence of electron beam (EB) irradiation and organoclay (OC) loading on the properties of low-density polyethylene (LDPE)/ethylene-vinyl acetate (EVA) blends was investigated. The samples were subjected to the EB irradiation with the dose values of 50 and 250kGy. X-ray diffraction (XRD), gel content, mechanical, thermal, and electrical properties were utilized to analyze the characteristics of the LDPE/EVA blends with and without OC at different irradiation dosages. Gel content analysis showed that the OC promotes considerably the insoluble part so that the LDPE/EVA blends filled with OC become fully crosslinked at 250kGy; possibly through the formation of further crosslinks between...
Study and Preparation of Suitable Polymer Compound for Radiation Masks
, M.Sc. Thesis Sharif University of Technology ; Mosavi Soghondikolaei, Abbas (Supervisor)
Abstract
External radiotherapy is a major method of treating cancer. In this method, penetrating rays such as X-rays, alpha, beta and gamma emitted from the device are used to treat cancer. In order to emitting rays only to the cancer cells, masks are used to stabilize the patient's body in the right position during the radiotherapy, so that the rays are not emitted to the healthy tissues of the patient's body. In this dissertation, first, different methods of making radiotherapy masks are examined. Next, polycaprolactone is proposed as the main material for making the mask. Due to its low tensile strength, this material alone is not suitable for the intended use. Therefore, the material was cured...
Investigation the Effect of Antioxidant on Amount of Crosslink and Mechanical Behavior of Peroxide Crossliked Polyethylene (PEX-A)
, M.Sc. Thesis Sharif University of Technology ; Pircheraghi, Gholamreza (Supervisor)
Abstract
Polyethylene is the most widely used plastic material in the world for reasons such as lightweight, good strength, good processability, low cost, and low maintenance cost, and very good chemical resistance. One of the applications of polyethylene that has received much attention in recent decades is its use in the manufacture of hot water pipes. To maintain the properties of polyethylene at high temperatures, it must be crosslinked at a proper level. Appropriate antioxidants should be used to prevent the degradation and oxidation of polyethylene during the process as well as long-term operation. Concomitant use of phenolic antioxidants for long-term stability during service and phosphorus...
Piezoelectric behavior of Gamma-radiated nanocomposite hydrogel based on PVP-PEG-BaTiO3
, Article Materials Science and Engineering B: Solid-State Materials for Advanced Technology ; Volume 276 , 2022 ; 09215107 (ISSN) ; Frounchi, M ; Dadbin, S ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
This study aimed to evaluate the properties of nanocomposite hydrogel (NCH) based on poly (vinyl pyrrolidone) (PVP), poly (ethylene glycol) (PEG), and Barium titanate (BTNPs). Gamma radiation at various doses (25 kGy, 35 kGy) was employed to prepare cross-linked hydrogel. The effect of PVP concentration, PVP/PEG ratio, and BTNPs content, and irradiation dosage on gel content and swelling ratio of synthesized hydrogels were determined. The Flory-Rehner equation was employed to calculate the network parameters. The FTIR results indicate that the chemical structure was deformed through crosslinking PVP macromolecule radicals. The XRD spectra indicated the cubic phase of BTNPs particles and the...