The characterization of mechanical and thermal properties of silane coated short glass fiber reinforced polyester composites

THE CHARACTERIZATION OF MECHANICAL AND THERMALPROPERTIES OF SILANE COATED SHORT GLASS FIBERREINFORCED POLYESTER COMPOSITES(M.Sc. Thesis)Muzaffer Can ŞAM LOĞLUGAZ UNIVERSITYINSTITUTE OF SCIENCE AND TECHNOLOGYJanuary 2007ABSTRACTIn this study, randomly oriented short glass fiber reinforced polyestercomposite materials were produced.For this objective, heat cleaning was applied to as-received glass fibersto remove the silane coatings on their surfaces. These glass fibers werecoated with 3 different silane coupling agents [ γ -(trimethoxysilyl)propylmethacrylate (MPS), γ -glycidyloxypropyltrimethoxysilane (GPS) and γ -aminopropyltrimethoxy silane (APS)] in 3 different concentrations(%0,25, %1, %1,5). Silane coated, heat cleaned and as-received fibersreinforced to unsaturatured polyester and composite materials wereproduced. Silane coated glass fiber reinforced composites werecompared with heat cleaning and as-received glass fiber reinforcedcomposites according to their mechanical and thermal properties. Alsothe effect of fiber ratio to mechanical properties of composites whichwere prepared by reinforcing %1 GPS coated glass fiber to polyesterresin in %10, %20 and %30 ratios was examined.In order to determine mechanical properties of the composite materials,three point bending and tensile tests were taken. Thermal properties ofcomposite materials were analyzed by using differential scanningcalorimeter (DSC). The fracture surface of the composite materials wasexamined by using scanning electron microscope (SEM).According to the test results, it was determined that silane coatingagents provide good adhesion on fiber-resin interfaces and thereforethe mechanical strength of composites increases. Silane coatingagents affects the mechanical properties of the composites positivelyup to %1 silane ratio. After %1 silane ratio, because of having lowstrength and thick interface the mechanical properties were influencednegatively. Two silane agent mixture coated fiber reinforcedcomposites are more durable than heat cleaned glass fiber reinforcedcomposites, but are more frail than other silane coated glass fiberreinforced composites. Nevertheless it was observed that when theshort glass fiber ratio increase, strength and modulus values increase,strain values decrease.According to the result of differential calorimeter (DSC) analysis; it wasobserved that type and quantity of silane coating did not affect glasstransition temperature (Tg) and decomposition temperature.The interactions between polyester resin and glass fibers, orientation ofglass fibers in polyester resin and conditions of silane coating on glassfibers were investigated by using SEM.Science Code : 912.1.092Key Words : silane, short glass fiber, polyester, mechanicalpropertiesPage Number : 94Adviser : Prof. Dr. H. Vecihi PAMUK