Fatma El Zahraa Ashour

In this study, polyurethane (PU)-milled light bulbs glass composites were synthesized and characterized. The main interest in this study that the polyurethane derived from renewable resources and waste glass are used to form the composite constituents as an attempt towards environmental preservation. Castor oil and polymeric diphenyl methane di-isocyanates (PMDI) were used in NCO/OH ratio = 2 for polyurethane synthesis. Milled glass with average particles size less than 300 μm were prepared based on waste light bulbs. Silane A1100 (as a compatibilizer) was used in order to improve the value of recycled milled glass beads. The adhesion force between polyurethane matrix and milled glass beads was evaluated using mechanical and physical tests. Scanning electron microscopy (SEM) was used to investigate dispersion and fracture surfaces of the composites. Infrared spectrum (IR), Differential scanning calorimetry (DSC) behavior, and Thermogravimetric analysis (TGA), were employed to characterize the developed composite materials in details. Chemical resistance (weight change, thickness swelling) was measured in oil, water and dilute acetic acid media. Furthermore, tensile strength and hardness were investigated using universal materials testing machines. A slight increase in the hardness values was reported along with the increasing in particulate fillers loading up to 10% as a considerable improvement has been detected when milled glass reached 20%. The DSC analysis showed the presence of treated milled glass beads influences the thermal behavior of pure PU and composites. This can be attributed to enhancing the physical bonding between PU and silica group. Waste milled glass showed a significant effect on the thermal degradation of the composites in the presence of coupling agent. Further analysis on the tensile strength of the composites indicated that such improved mechanical properties may be attributed to the presence of coupling agent.

Polyurethane (PU) elastomer based on castor oil and polymeric diphenylmethane diisocyanate (PMDI) was synthesised with NCO/OH ratio = 2 as a polymeric matrix. Polyurethane was composited with rice husk with average particle size less than 200 μm. Ground rice husk was pretreated by steam and sodium hydroxide solution in order to study and evaluate the effect of different surface treatment methods on the properties of the polyurethane composites. Scanning Electron Microscopy (SEM) was used to investigate dispersion and fracture surfaces of the composites. Mechanical test (hardness), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC), were employed to characterise the developed composite materials in details. Composite polyurethanes based on treated and untreated rice husk showed different physical, chemical and mechanical properties. SEM micrographs of PU-treated rice husk (steam) displayed rice husk tightly embedded in the PU matrix with uniform distribution. The steam treatment increased the interfacial adhesion within the material, which showed a high thermal stability. PU-treated rice husk (sodium hydroxide 10 wt.%) showed poor mechanical properties. Untreated rice husk showed moderate mechanical properties as compared to the preceding cases.