Superimposed reduced moduli

Figure 2. Theoretical curves for superimposed reduced moduli Gd /RT(mol/ cm 3) of epoxy-amine networks versus the gel fraction ws. Fraction of epoxy groups in monoepoxide is O, 0 , 0.2 A, 0.33 V, 0.5. Key O, , A, V, dry networks , A, , swollen networks value of front factor A indicated.

Fig. Z4 (a) Temperature ramp at a frequency a> = lOrads (strain amplitude A = 2%) for a nearly symmetric PEP-PEE diblock with Mn = 8.1 X 104gmol l, heating from the lamellar phase into the disordered phase. The order-disorder transition occurs at 291 1 °C, the grey band indicates the experimental uncertainty on the ODT (Rosedale and Bates 1990). (b) Dynamic elastic shear modulus as a function of reduced frequency (here aT is the time-temperature superposition shift factor) for a nearly symmetric PEP-PEE diblock with Mn = 5.0 X 1O g mol A Shift factors were determined by concurrently superimposing G and G"for w > and w > " respectively. The filled and open symbols correspond to the ordered and disordered states respectively. The temperature dependence of G (m < oi c) for 96 < T/°C 135 derives from the effects of composition fluctuations in the disordered state (Rosedale and Bates 1990). (c) G vs. G"for a PS-PI diblock with /PS = 0.83 (forming a BCC phase) (O) 110°C (A) 115°C ( ) 120°C (V) 125°C ( ) 130°C (A) 135°C ( ) 140°C ( ) 145°C. The ODT occurs at about 130°C (Han et at. 1995).

Ultralow load indentation, also known as nanoindentation, is a widely used tool for measuring the mechanical properties of thin fdms and small volumes of material. The principle is to pushing in a hard material tip called the indenter into the analyzed sample and to measure the curve load-penetration. A modified commercial nanoindenter (Nano indenter XP - MTS) was used to characterize coated materials. The device allows to measure the contact stiffness with superimposing a harmonic oscillation (small amplitude of 3 nm, constant frequency of 32 Hz) to the continuous penetration of the indenter into the sample. This specificity allows one to continually measure the elastic modulus and hardness according to the penetration depth. Loubet et al. demonstrated that reduced Young modulus and hardness for a Berkovich indenter with a dynamic measurement method could be deduced from the following equations [11] ... 

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