Mettler hot stage

As observed on a Mettler Hot Stage FP 52 with FP5 controller, the sample appeared as birefringent needle-like crystals which melted from 115-117°C. The sample did not recrystallize from the melt (5). 

Materials and Processing. Copolyesters of poly(ethylene terephtha-late) (PET) and para-oxybenzoic acid (FOB) were supplied by the Tennessee Eastman Corporation. Past work Indicates the copolyesters form thermotropic liquid crystalline phases at compositions containing more than 30 mole% POB (26,27,28). The composition of the copolyester studied here contains 60 mole% POB. Quiescent liquid crystalline films were made by compression molding the copolyester at 210, 230, 255, and 285 C, and followed by a quench Into Ice water, ambient air, or cooled In the press with the power off. Film thicknesses ranged between 0.05-0.15 mm. Another sa(q>le of the 40/60 PET/POB copolyester was melted at 270 °C In a Mettler hot stage, manually sheared between glass slides, and then ambient air cooled. 

Figure 9.28. Microreflectance apparatus. A, B L microscope B. B L monochromator and lamp C, photomultiplier tube D, amplifier and power supply E, X-Y recorder F, strip-chart recorder G. Mettler hot stage H, reversible motor J, relay and timer (45).

The morphology and the isothermal radial growth rate of PEO spherulites in the blends were studied on thin films of these samples using a Reichert polarizing microscope equipped with a Mettler hot stage. The films were first melted at 85° C for 5 minutes, following which they were rapidly cooled to a fixed crystallization temperature T and the radius of the growing spherulites was measured as a function of time. 

The thermal optical data were obtained using a photocell in conjunction with a Bausch-Lomb SOOyV V0M7 recorder, programmed by a Mettler hot stage. 

The n and nj values as functions of ten jerature were determined with the aid of a Leitz-Jelley-microrefractometer, using a sodium lamp as light source. The birefringence was also determined by a conoscopic method using a polarizing microscope. The temperature in both experiments was adjusted by a Mettler hot stage FP-52 with the control unit FP-5. 

The phase separation was followed by means of a Leitz polarizing optical microscope with a Mettler hot stage. 

Leitz polarizing microscope equipped with a Mettler hot stage. 

Fig. 3 Experimental setup that demonstrates the macroscopic expansion of the oriented fiber by lifting of a dime on the inclined plane of a Mettler hot stage (top). Expanded images collected at 25°C bottom left) and at 80°C bottom right) of the oriented fiber generated from the achiral polymer in Fig. la during lifting of 250-times its weight via thermally fueled unwinding of its helix at the cisoid-to-transoid transition. Reproduced with permission Irom [50]. Copyright 2008 American Chemical Society...

Denny et al. >27 9 used a Mettler hot stage microscope to observe changes in sample i ysical dimensions occiuring in particulate polystyrene specimens with increasing temperature. Over 15 monodisperse polystyrene molecular weight standards, obtained from both the Pressure Chemical Company and the Dow Chemical Company, have been examined, as well as several different molecular weight series of substituted polystyrenes. ... 

Hot stage microscopy was performed using a Mettler FP52 temperature controller at a rate of 3°/minute. Melting began at 268.2°, and by 271.4° all crystals were melted. The yellow melt slowly turned orange-brown. Cooling showed no recrystallization at ambient temperature. 

FIGURE 7.6 Mettler FP84HT hot-stage accessory. (From Rapid and Automatic Determination of Thermal Values Product Brochure, Mettler-Toledo Company, Hightstown, NJ, 1996. With permission.)... 

Figure 9.21. The Mettler FP-2 hoi stage, (a) Schematic diagram of the control system (fc) schematic diagram of hot stage.

Wendlandt (45) used a microscopic method for the determination of the reflectance of the sample. The apparatus, as shown in Figure 9.28, consisted of a low-power (100 x, generally) reflection-type microscope, A, which is illuminated by means of a monochromator, B. The reflected radiation is detected by a photomultiplier tube, C, and amplifier, D, and recorded on either an X-Y recorder, E, or a strip-chart recorder, F. In order to heat the sample to 250°C, a Mettler Model FP-2 hot stage, G, is employed. Either isothermal ( 1CC) or dynamic sample temperatures may be attained by this device. The sample is moved through the illuminated optical field by means of the reversible motor, H. The motor is reversed at preset intervals by a relay circuit and timer, J. Thus, it is possible to scan the reflectance from the sample, which may consist of a single crystal or a powdered mixture. Powdered samples may be placed directly on the heated microscope slide or... 

At some cost to the uniformity of the field of illumination it is possible to use the microscope in conjunction with a hot stage (Mettler FP2) aind directly record concentration chcuiges during crystal growth eind melting. 

CrystaUized complexes or epoxy-modified amine mixtures could be melted or cured between two glass plates using a Mettler FP 82 hot stage, coupled with an FP 90 central processor, under POM (Laborlux 12POLS from Leica, equipped with a CCD IRIS color video camera from Sony). Crystals were heated from 25 to 100 °C at a rate of 1 K min and mixtures were cured from 20 to 250 °C (see Section 7.3.4). 

Method Crystallization studies were carried out on an optical microscope, (Carl Zeiss), and a hot stage (Mettler FP-82). The temperature on the stage can be controlled to within O.rC and maximum cooling (or heating) rates of 20 C/min can be achieved. Glass slides and cover slips were cleaned in chromic acid and distiled water in ultrasonic bath. Polymer samples were placed between the glass slide and cover slip and pre-treated by melting to 280"C for 20 s. For crystallization studies the initial temperature, Ti, was set at 255 C. 

The inherent viscosity measurements of the polymers were made at 40°C using a Ubbelohde viscometer. Solutions of 0.5 g/dl in TCE were used for the measurements. The thermal transitions of the polymers were measured using a Perkin-Elmer DSC-II at the heating and cooling rates of 10°C/min under a nitrogen atmosphere. The peak maximum positions were taken as those of the transition points. Optical textures of the polymer melts were observed on the hot-stage (Mettler FP-2) of a polarizing microscope (Leitz, Ortholux). 

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