Synthesis and Study of Some Prepared Polyester Nanocomposites

Abstract

The present study aims to prepare samples of unsaturated polyesters (UP) through the reaction of dimethyl terephthalic acid with ethylene glycol in presence of maleic anhydride. As well as modifyingit through its preparation in presence of excess of ethylene glycol to give modifiedunsaturated polyesters (UP-EG), then use those prepared resins as matrices for the preparation of conventional composites using filler materials from clay (Egyptian bentonite) (EB) or carbon black (CB) for the production of modifiedcomposites (UP-EG/EB) and (UP-EG/CB) respectively. The prepared composites were studied and compared their properties and study the effect of the presence of different ratios of the filler materials on the different properties. Also filler materials were used in the nanoscale such as the prepared organoEgyptian bentonite (OB), or carbon nanoparticles (CNP), or multiwall carbon nanotubes (MWCNT), in the preparation of unmodified nanocomposites (UP/OB), (UP/CNP), (UP/MWCNT) and also modified nanocomposites (UP-EG/OB, UP-EG/CNP), (UPEG/ MWCNT),respectively. The study is divided into three main parts: Part I It includes the preparation of samples of unsaturated polyesters (UP) through the reaction of dimethyl terephthalic acid with ethylene glycol in presence of maleic anhydride. Modifications of these samples through its preparation in the presence of excess of ethylene glycol to obtain modified unsaturated polyesters (UP-EG). The chemical structure for the prepared resins was confirmed by FTIR. Its mechanical, thermal properties were studied and also i the chemical resistance in some solutions. Results indicated that resin of modified polyesters have better mechanical and thermal properties, and chemical resistance than the unmodified resin. Part II It includes the preparation of conventional composites of unsaturated polyesters using the prepared resins as matricesand use of different ratios of filler materials (3,5,7,10 , 20,30,40 ,50, and 60%) of the clay (Egyptian bentonite) (EB) or carbon black (CB) to obtain unmodified composites (UP/EB), (UP/CB), and modified composites (UP-EG/EB), (UP-EG/CB) respectively. The morphological structure of these composites was studied using a transmission electron microscope high-power (TEM). Also study of the effect of different ratios of the filler materials on the properties of the prepared composites prepared from the chemical resistance, thermal and mechanical properties. The results show that increasing the ratio of filler materials in the samples (till 40%) increases the chemical resistance, thermal and mechanical properties. Also the results show that composites based on modified polyesters show marked improvement in the chemical resistance, mechanical and thermal properties than the unmodified composites. Part III: It includes the preparation of nanocomposites from unsaturated poly esters using the prepared resins as matrices, and using different ratios of nano filler materials (3,5, 7, and 10 %) of the Egyptian nanoclay (organo ii Egyptian bentonite) (OB), which was prepared from Egyptian bentonite usingoctadicyl ammonium salt as a surface active material .The morphological structure was studied using transmission electron microscope high-capacity (TEM) and X-ray diffraction (XRD) analysis, and also study the thermal decomposition(TGA). Moreover, nanocomposites were prepared using different ratios (0.01 - 0.05 %) of carbon nanoparticles (CNP), or multi-wall carbon nanotubes (MWCNT) for the preparation of unmodified nanocomposites (UP/CNP), (UP/MWCNT) as well as modified nanocomposites (UP-EG/CNP), (UPEG/ MWCNT) respectively The morphological structure of these nanocomposites was studied using a transmission electron microscope high-power TEM, X-ray diffraction (XRD) analysis and studied the effect of the ratios of filler materials on the properties of the prepared nanocomposites from the chemical resistance, thermal and mechanical properties, as well as electrical properties. The results have shown that increasing the ratios of the filler materials in the samples (till to 0.04%) increases the chemical resistance, the thermal and mechanical properties and also led to an improvement in the electrical properties. It has also appeared that, nanocomposites based on modified polyesters characterized by effective and noticeable improvements in the properties of chemical resistance, thermal and mechanical properties. The results proved that multi-wall carbon nanotubes (MWCNT) nanocomposites show good electric effective where it has transferred the nanocomposites from semiconductors to good electrical conductors at low concentrations (0.02%). iii