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equipped with a computer image analysis system, aftergold coating.RESULTS AND DISCUSSIONSEffect of nano- and Micro-particles Additions on theRheological Properties of the Adhesives on the viscosity of adhesive formulations, rheological Albipox are shown in Figure 3 for different rates of shear Bohlin software.From these graphs it is evident that the viscosity of eachadhesives decreases with increase in shear rate, i.e. each adhesives need to be subjected to increasing and decreasingshear to generate a hysteresis loop.However this was not done due to the limitations of theequipment. However by observation and during handling,The viscosity of Timberset was not determined as it has avery high viscosity and crosslinks rapidly so damage to theequipment would have occurred. The time for the shearingto take place at a constant rate of increase in shear ratevaried from one adhesive to another.as it required less shear stress to reduce its viscosity. TheAlbipox matrix contains a rubbery phase and showedthe least pronounced pseudoplasticity (i.e. the viscositydecreasing with increasing shear rate) and it had the highestviscosity at low shear rates, indicating physical interactionbetween the epoxy and the rubbery phases. It is possiblethat cavitation or debonding of rubber particles took placewhich increased the resistance of the adhesive formulationEffect of Nano- and Micro-particles Additions on theThermal Properties of Adhesives temperature for the different adhesive systems used. Thestorage modulus E’ represents the elastic properties anddemonstrates the stiffness. The storage modulus valueswere not constant in glassy region but slightly decreasedwith temperature. As pointed out by Lewis and Nielsen relaxations in the polymeric phase which account forthe negative slope of E’ versus temperature in the glassyregion. According to Mohd Ishak and Berry (1994), therelaxation peak is assigned to the breakage of hydrogenbonds between the polymer chains which induces longrange segmental motion in the amorphous area. The wholecurve of the dynamic storage modulus versus temperatureconsists of three stages. (The curve for Timberset is used asan example to explain the general characteristics).to the gelation of the macromolecule movement chains(Yao et al. stage, the molecule chains starts to move freely, and themodulus decreases rapidly to 1 GPa because of the largedeformation of the material.In the third stage, the whole molecular chain causes irreversible deformation, therefore the modulus suddenlyfalls to zero. From Figure 4, it can also be seen that, onthe whole, the dynamic mechanical behaviour of the threeadhesives is similar. The differences are in the storagemodulus and the temperature of the main transition fromelastic to viscoelastic behaviour, which are related to theThe ceramic particles in Timberset, show a remarkablestiffness effect on the adhesive with the highest E’ the adhesives are in the order of Timberset > Albipox > the static elastic modulus obtained from authors’ previouswork (Ahmad et alThe dynamic modulus was found to be higher thanmodulus in the rubbery plateau region is proportionalto either the number of crosslinks or the chain lengthbetween entanglements (Menard, 1999). For the threeadhesives other than Timberset the storage moduli aresimilar and very small in the rubbery zone. The rubberyplateau modulus for Timberset is found to be higher thanthe other adhesives.The addition of high modulus ceramic particle hasallowed Timberset to retain a higher modulus even at atemperature above the glass transition. Timberset is again4b) which means there is large amount of damping in theThe glass transition temperature of the adhesives weredetermined based on the onset E’ value from E’ versustemperature curves and the T g 40
700800Viscosity (Pas) Viscosity (Pas)600700500600400500300400200300Viscosity100Shear stress2000Viscosity1000 10 20 Shear 30 stress 40Shear rate (1/s)00 10 (a) 20 30 40Shear rate (1/s)70060080050070040060030050020040010030002001000Shear stress Shear (Pa) stress (Pa)16000140001200016000500400500Viscosity (Pas) Viscosity (Pas)10000140001200080001000060004000800020006000300400200300viscosity 100200shear stress400000viscosity 1000 2 4 6 8 10 12 142000Shear rate (1/s) shear stress000 2 4 6 8 10 12 14Shear rate (1/s)Shear stress Shear (Pa) stress (Pa)(b)Figure 3. Viscosity and shear stress plotted versus shear rate for (a) CB10TSS, and (b)Albipox.
Page 1 and 2: ContentsASM Sc. J.Volume 7(1), 2013
Page 3 and 4: INTERNATIONAL ADVISORY BOARDAhmed Z
Page 5: The Academy of SciencesMalaysia (AS
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Page 40 and 41: 4.2 × 10 -5Magnetic energy (Em) Ma
Page 42 and 43: 2.0 × 10 -5Inductance (L)Magnetic
Page 46 and 47: addition, examination of the freque
Page 50 and 51: Storage modulus (Pa)1.80E+101.60E+1
Page 52 and 53: (a)(b)(c)Figure 6. Micrographs: (a)
Page 54 and 55: 0 20 40 60 80 100 120 140 160 180 2
Page 56 and 57: 0.00 20 40 60 80 100 120 140 160180
Page 58 and 59: 0 20 40 60 80 100 120 140 160Temper
Page 60 and 61: 2.0100.00 20 40 60 80 100 120 140 1
Page 62 and 63: 3.02.53.02.02.5CB10TSSAlbipoxTimber
Page 64 and 65: Figure 18. SEM micrographs of the f
Page 66 and 67: Crawford, E & Lesser, AJ 1998, ‘T
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