Standard laboratory viscometers

Standard laboratory viscometers have a shear rate range 0.1 -1000 s-i. At the moment these include the... 

Elemental Analysis and Physical Properties. Elemental analysis was accomplished by conventional microanalytical techniques in a commercial testing laboratory. Density, refractive index, average molecular weight (VPO), Conradson carbon residue, and ash content were determined by standard methods. Viscosity was determined by a cone-plate viscometer. Simulated distillation was accomplished using a y4" x 18" column of Anachrome Q, 3% Dexil 300, programmed from -30 to... 

Critical measuring and test equipment identified as being critical parts of the quality system should be properly calibrated and maintained. Calibration should be traceable to recognized standards. This includes all in-process instruments identified as quality instruments, as well as test equipment used in the laboratory. Test equipment includes laboratory instruments such as spectrometers, viscometers and other apparatus, as well as reagents, buffer solutions and standard solutions. 

SEC experiments were carried out on a Watters 150CV instrument (Waters Associates, Milford, Massachusetts, U.S.A.) equipped with both differential refractive index single-capUlary viscometer detectors. The solvent/mobile phase was H20/0.02% NaNs, at the flow rate of 1.0 ml/ min. Pump, solvent, and detector compartments were maintained at 50°C. Separation occurred over a column bank consisting of three analytical columns preceded by a guard column Shodex KB-G, KS-802, KS-803, and KB-804 (Phenomenex, Torrance, California, U.S.A.). Universal calibration was performed using a series of oligosaccharides (Sigma, St. Louis, Missouri, U.S.A.), and PuUuIan Standards (American Polymer Standards, Mentor, Ohio, U.S.A., and Polymer Laboratories, Amherst, Massachusetts, U.S.A.). 

Such viscometers are available with varying capillary tube diameters. This allows a wide range of viscosity values to be measured at flow times suited to routine laboratory work. In practise, this type of equipment is only used for simple characterisation techniques such as quality control checks, and usually only when a fit for purpose polymer has been characterised and standard conditions defined in order to provide a benchmark or reference result against which other samples can be compared. 

FTIR spectra were obtained on a MIDAC spectrophotometer. The H NMR and NMR spectra were collected on a 300-MHz Bruker AM spectrometer, using deuterated water as a solvent and with trimethylsilane (TMS) as internal standard. Viscosities of the copolymer solutions (50-50, wt-wt) were measure by a cone and plate viscometer, using a Cap 2000 Viscometer (Brookfield Engineering Laboratories, Inc., Stoughton, MA), at 25°C. An Instron universal testing machine (Instron Model 4204, Instron Corp., Canton, MA) was used to determine mechanical properties. 

The actual values for these standards are established and annually reaffirmed by cooperative tests. In 1991, tests were made using 15 different types of viscometers In 28 laboratories located In 14 countries. 

Characterization. Absolute viscosities of the diols were measured with a Brookfield viscometer (model RVTD, spindle no. 4). The viscometer was calibrated with silicone oil viscosity standards supplied by Brookfield Engineering Laboratories, Inc. The diol was contained in a test tube, I.D.= 7.25 mm, and temperature control was achieved through a water bath. 

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