Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi University, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2007
Thesis Language: Turkish
Student: HANDE YAVUZ
Supervisor: NURSEL DİLSİZ
Abstract:Polyolefins such as polyethylene and polypropylene has low thermal and mechanical properties and also can burn readily when subjected to flame. Bulk property modification or layer deposition in micrometer or nanometer scale can be performed to improve flame retardancy. In this study, plasma surface modification of polyethylene (PE), bi-axially oriented polypropylene (BOPP) films and cotton fabrics was carried out by using trimethyl borate, trimethylboroxine, tri-t-butyl borate, trimethylene borate compounds. The modified chemical structure was examined by Fourier Transform Infrared (FTIR) and X-ray Photoelectron Spectroscopy (XPS). Surface topography and morphology was investigated by using Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM), respectively. The flame retardancy was evaluated according to the ASTM D2863 standard (LOI). The thermal stability was indicated by Thermogravimetric Analysis (TGA) and Differantial Thermal Analysis (DTA), respectively. The contact angle measurements were carried on Drop Shape Analysis (DSA) equipment and also mechanical tests were evaluated for BOPP and PE films. At optimum plasma conditions (30W and 30 min plasma treatment), LOI of BOPP films was obtained increased from 17,9 to 24,0. The chemically bonded elements which gathered from XPS surface analyses of original BOPP and 55W 60 minutes trimethyl borate plasma treated BOPP film were C, O and C, O, B respectively. It was found that 11,2% B element detected in the surface region of plasma treated BOPP film. At different plasma conditions dissimilar kind of plasma depositions were observed by exploring AFM and SEM pictures. Besides, by evaluating contact angle measurements it has seen that trimethyl borate plasma modified BOPP films were gained hydrophilic character. Mechanical characterization showed that at 80W plasma power treated BOPP films' tensile strength was raised from 57 to 155 MPa while the maximum strain was remained approximately unchanged. It was seen that there was no such linear relation between plasma power and mechanical behavior of polyolefin films. The results showed that trimethyl borate plasma modification could be used as an alternative method to enhance flame retardancy of BOPP film.