Contents - Akademi Sains Malaysia

Z. Ahmad et alStorage modulus (Pa)1.610 101.410 101.210 101.010 108.010 96.010 94.010 92.010 9CB10TSSAlbipoxTimberset0.00 20 40 60 80 100 120 140 160 180 200Temperature (ºC)(a)Loss modulus (Pa)1.810 91.610 91.410 91.210 91.010 98.010 86.010 84.010 82.010 8CB10TSSAlbipoxTimberset0.00 20 40 60 80 100 120 140 160 180 200Temperature (ºC)(b)Tan delta8.010 –16.010 –14.010 –12.010 –10.00Storage modulus (Pa)1.610 101.410 101.210 101.010 108.010 96.010 9CB10TSSAlbipoxTimbersetTan delta8.010 –16.010 –14.010 –12.010 –1CB10TSSAlbipoxTimberset4.010 90.0110 92.010 920 40 60 80 100 120 140 160 180 2000 20 40 60 80 100 120 140 1600.00Temperature (ºC)0 20 40 60 80 100 120 140 160 180 Temperature 200 (ºC)0 50 100 150Temperature (ºC)(c)Temperature (ºC)Loss modulus (Pa)510 9410 9310 9210 9CB10TSSAlbipoxTimbersetCB10TSSAlbipoxTimbersetTan delta1.41.21.00.80.60.40.20.0–20 9Figure 13. Graph of: (a) Storage modulus versus temperature; (b) Loss modulus versus temperature and(c) Tan tan d versus temperature for all adhesives after CB10TSS aged at 50°C.CB10TSS1.4AlbipoxAlbipoxTimbersetTimberset1.20 9epoxies do not go to complete reaction (Herzog 1.0 et al 0 9therefore post-curing was necessary in order to achieve resulting in a decrease in free space, reduction in water0.8a high degree of crosslinking. Most room-temperature T g .0 90 900 cured epoxies have T g 0.60.4The T g values obtained from DMTA 0.2 methods afterexposure to all the environmental conditions are 0.0 –20 0 20 40 60 T g s ofall adhesives reduced as humidity increases at roomtemperature and reduced much higher after soaking inwater. The water alters the molecular structure of theadhesive by an increase in the molecule mobility which80 is 100 due 120140 to the 160 softening 180 200 or plasticizing effect and this isin Temperature water, the (ºC) T g Temperature manifested (ºC) as dimensional changes and reductions in T g values (Lee 1991).values of thermal properties. By post-curing the adhesives T g of Timberset increased byis a denser and more rigid polymer than Albipox andIn contrast, when the temperature increases at highhumidity, the T g s tend to increase which proved the effectof further crosslinking. When a polymer is crosslinked,covalent bonds are formed between the polymer chains,which bring them closer together and reduce free volumeTan delta51