Magisterarbeit, 2010
97 Seiten, Note: 1
1 INTRODUCTION
1.1 Introduction to polymers
1.2 Orientations of the work
1.3 Scope
2 RADIATION EFFECTS ON POLYMERS
2.1 Introduction
2.2 Radiation sources
2.3 Microtron
2.4 Terminology and units
2.5 Radiation induced chemical changes in polymer
3 EXPERIMENTAL METHODS
3.1 Preparation of sample
3.2 Thickness measurement
3.3 Irradiation
3.4 Electrode coating
3.5 X-ray Diffraction
3.6 Calculation of crystallinity
3.7 IR spectra
3.8 Measurements
4 RESULT AND DISCUSSION
4.1 X-ray Diffraction analysis
4.2 FTIR Analysis
4.3 Conductivity Measurements
5 CONCLUSION
The primary objective of this study is to systematically investigate the effects of high-energy electron beam irradiation on the electrical properties, specifically the resistivity, of Polyvinyl Chloride (PVC). By comparing I-V characteristics before and after irradiation at various doses, the research aims to establish how molecular structural changes influence the material's conductive behavior.
1.1 Introduction to polymers
Polyvinyl chloride was accidentally discovered on at least two different occasions in the 19th century, first in 1835 by Henri Victor Regnault and in 1872 by Eugen Baumann. On both occasions, the polymer appeared as a white solid inside flasks of vinyl chloride that had been left exposed to sunlight. In the early 20th century, the Russian chemist Ivan Ostromislensky and Fritz Klatte of the German chemical company Griesheim-Elektron both attempted to use PVC (Polyvinyl Chloride) in commercial products, but difficulties in processing the rigid, sometimes brittle polymer blocked their efforts. In 1926, Waldo semon of B.F Goodrich developed a method to plasticize PVC by blending it with various additives. The result was a more flexible and more easily processed material that soon achieved widespread commercial use (13).
Polymers and polymer composition with Vinyl was first used in electrical applications more than a half century ago as a replacement for rubber insulation. Today, vinyl commands nearly half of the market for electrical applications such as wire insulation and sheathing. That's because of vinyl's reliable durability and outstanding safety record. But the relatively low electrical conductivity is exhibited by the polymers like polyvinyl chloride gained importance during the past decades. The electrical conduction in polymer films has much importance due to the discovery of the memory phenomenon (Kryezewski 1975) and has wide application now a day in thin film devices (Mcad 1961). In recent years, because of the need for electrostatic charges dissipation, electromagnetic shielding etc, new polymers with electrical conductivity have been formulated particularly because of their electrographic and solar cell applications (11). Many synthetic polymers (Kumar et al 1985) like polypyrrloe, polycarbazol and polyacetylene etc have been studied.
1 INTRODUCTION: Provides an overview of the role and history of polymers, specifically PVC, and outlines the research context regarding their electrical applications and susceptibility to radiation.
2 RADIATION EFFECTS ON POLYMERS: Discusses the fundamentals of radiation sources, their interaction with polymeric materials, and the resulting physical and chemical modifications like cross-linking and degradation.
3 EXPERIMENTAL METHODS: Details the preparation of PVC samples, the irradiation process using a Microtron, and the analytical techniques employed, including X-ray Diffraction, FTIR, and electrical conductivity measurements.
4 RESULT AND DISCUSSION: Presents and analyzes the data obtained from XRD and FTIR studies and discusses the observed relationship between irradiation dosage and electrical conductivity.
5 CONCLUSION: Summarizes the study's findings, confirming that electron beam irradiation alters the structural characteristics of PVC, leading to increased crystallinity and changes in electrical conductivity.
Polyvinyl Chloride, PVC, Electron Beam Irradiation, Polymer Degradation, Cross-linking, Crystallinity, Electrical Conductivity, X-ray Diffraction, FTIR Analysis, Radiation Effects, Polymer Synthesis, Electrical Insulators, I-V Characteristics, Microtron, Material Science.
The research focuses on investigating how high-energy electron beam irradiation affects the electrical properties, particularly the electrical resistivity and conductivity, of Polyvinyl Chloride (PVC).
The central themes include polymer science, the effects of ionizing radiation on material properties, experimental characterization techniques for polymers, and the study of electrical conduction mechanisms in irradiated plastic materials.
The primary goal is to perform a systematic investigation comparing the I-V characteristics of PVC before and after irradiation to understand how radiation-induced molecular changes, such as shifts in crystallinity, influence the material's electrical performance.
The study utilizes electron beam irradiation, X-ray Diffraction (XRD) for structural analysis, Fourier Transform Infrared (FTIR) spectroscopy for chemical structural changes, and Keitley source meter units to record I-V characteristics.
The main body covers the theoretical background of radiation effects on polymers, detailed experimental procedures, the presentation of results from diffraction and infrared analysis, and a discussion on conductivity measurements related to irradiation dose.
Key terms include PVC, electron beam irradiation, crystallinity, electrical conductivity, FTIR analysis, and polymer degradation.
The study indicates that irradiation alters the polymer structure, leading to an increase in crystallinity and the production of free radicals due to chain scission or cross-linking, which facilitates improved electrical conductivity.
The Microtron is the circular accelerator used to deliver the specific 8.75 MeV electron beam required for irradiating the PVC samples at controlled cumulative doses.
The experimental results show that the intensity of peaks in XRD patterns increases with the irradiation dose, indicating that the amorphous nature of the pure PVC sample progressively changes into a more crystalline structure.
Der GRIN Verlag hat sich seit 1998 auf die Veröffentlichung akademischer eBooks und Bücher spezialisiert. Der GRIN Verlag steht damit als erstes Unternehmen für User Generated Quality Content. Die Verlagsseiten GRIN.com, Hausarbeiten.de und Diplomarbeiten24 bieten für Hochschullehrer, Absolventen und Studenten die ideale Plattform, wissenschaftliche Texte wie Hausarbeiten, Referate, Bachelorarbeiten, Masterarbeiten, Diplomarbeiten, Dissertationen und wissenschaftliche Aufsätze einem breiten Publikum zu präsentieren.
Kostenfreie Veröffentlichung: Hausarbeit, Bachelorarbeit, Diplomarbeit, Dissertation, Masterarbeit, Interpretation oder Referat jetzt veröffentlichen!

