The curing characteristics of blended MFSR were studied by a Monsanto moving disk rheometer (MDR-2000, Alpha Technologies) at 160[degrees]C.
To evaluate low temperature performance of blended MFSR and low temperature effects, such as crystallization, or those effects that were introduced by low temperature incompatibility of MSR and FSR, differential scanning calorimetry (DSC) measurements were performed on a Pheometric scientific DSC SP instrument at a heating rate of 10[degrees]C/min from -150[degrees]C to 20[degrees]C.
Morphological observations were made by a scanning electron microscope (SEM; JSM-7600F, JEOL) on the tensile broken surface of blended MFSR. The surfaces of the specimens were sputter coated with gold.
Mechanical properties of blended MFSR, including tensile strength, tear strength, and elongation at break were measured according to ASTM D412 and D624 procedures at a crosshead speed of 500 mm/min using dumbbell-shaped test pieces in an electronic rubber tension tester (XLD-A, Second Experimental Machine Factory, Changchun, China) at room temperature.
The hot oil resistance of blended MFSR was determined according to ASTM D471-1998 in ASTM 1# oil, ASTM 2# oil, and ASTM 3# oil.
Figure 1 showed the curing curves of MSR, blended MFSR and FSR at 160[degrees]C.
The curing characteristics of blended MFSR, expressed in terms of the minimum and maximum values of torque, [M.sub.L] and [M.sub.H], the scorch time, [t.sub.SI] and the optimum cure time, No, were compiled in Table 2.
The reaction rate constant k values tabulated in Table 3 were obtained from the plot of ln([M.sub.H] - [M.sub.L]/[M.sub.H] - [M.sub.t]) against t and the obtained graphs were straight lines, which indicated the cure reaction of blended MFSR followed first order kinetics.
To evaluate low temperature performance of blended MFSR, differential scanning calorimetry (DSC) measurements were performed.
Correlacao significativa e positiva entre COL e as demais variaveis (Ap, Ne, MSpA e MFSR) e entre MFSR e Ne, Ap e MSpA foram encontradas para o presente trabalho, e pode ser explicada pela dependencia entre estas variaveis.
Desta forma, tambem para o presente trabalho, e possivel sugerir que, apesar da alta colonizacao e da boa altura das plantas, as diferencas entre as progenies, frente ao baixo numero de esporos, MSpA e MFSR, podem nao ser atribuidas apenas a associacao com FMA, mas tambem as diferencas entre as progenies em si, ou seja, do efeito genotipo frente as condicoes do solo.
Existe variabilidade entre os genotipos de Hymenaea stigonocarpa no crescimento (Ap, MSPA e MFSR) e micorrizacao (COL e NE), com destaque para duas progenies (JC7 e JC18), pelos valores mais elevados.