Plasticity number

Polarity Parameter. Despite their appareat simplicity, these parameters, ( ), show a good correlatioa with plasticizer activity for nonpolymeric plasticizers (10). The parameter is defiaed 2ls (j) = [M A j Po)]/1000 where M = molar mass of plasticizer, = number of carboa atoms ia the plasticizer excluding aromatic and carboxyHc acid carbon atoms, and Pg — number of polar (eg, carbonyl) groups present. The 1000 factor is used to produce values of convenient magnitude. Polarity parameters provide useful predictions of the activity of monomeric plasticizers, but are not able to compare activity of plasticizers from different families. 

This is similar to the analysis obtained by Ainsley and Smith (see Chhabra, 1992) using the slip line theory from soil mechanics, which results in a dimensionless group called the plasticity number ... 

ISO 200722 specifies a rapid plastimeter procedure using an instrument with one platen either 7.3, 10 or 14 mm diameter and the other platen of larger diameter than the first (i.e. disc type method). The size of the first platen is chosen such that the measured plasticity is between 20 and 85. The test piece is cut with a punch which will give a constant volume of 0.40 0.04 cm, the thickness being approximately 3 mm and the diameter approximately 13 mm. The test piece is pre-compressed to a thickness of 1 0.01 mm within 2 sec and heated for 15 sec. The test load of 100N is then applied for 15 sec when the test piece thickness is measured. The usual temperature of test is 100°C and the result is expressed as the thickness of the test piece at the end of the test in units of 0.01 mm and called the rapid plasticity number. The Wallace rapid plastimeter, and presumably other commercial instruments, conform to this specification but it would be sensible to check with the manufacturers. A technically identical method is given in BS 903 Part A5923. 

ISO 732324 specifies a parallel plate test based on the Williams plastimeter with plates 4 cm in diameter. The test piece is 2.00 0.02 cm3 in volume and can conveniently be a cylinder 16 mm diameter and 10 mm thick. As discussed above, a close tolerance on volume is necessary for this type of plastimeter. The test piece is preheated for 15 min (the temperature of test is usually 70°C or 100°C) and compressed under a force of 49N. The thickness of the compressed test piece is measured in mm and this value multiplied by 100 quoted as the plasticity number. The preferred time of application of the force is 3 min. The correction to the standard in 2003 was to change the tolerance on the force from 0.05N to 0.5N. 

The ISO method also gives a procedure for measuring the recovery of the test piece after removal of the load. The height of the test piece is measured after lmin recovery at the test temperature. The recovery value is reported as the difference between plasticity number and recovered height multiplied by 100. 

BS 903 Part A59.1, 1997. Methods using plastimeters - Determination of the rapid plasticity number. 

ISO 7323 1985/Cor 1, 2003. Determination of plasticity number and recovery number -Parallel plate method. 

Plasticity number according to Rieke = 33 - 15 = 18 5. Grain size distribution... 

A group of (originally) seven limits of soil consistency, or relative ease with which material can be deformed or made to flow. The only Atterberg limits that are still in common use are the liquid limit, plastic limit, and plasticity number. 

Suspension films separating two solid surfaces, and Wetting films separating a solid or liquid from a vapour. The minimum water content for which a small sample of soil or similar material will barely flow in a standardized test method. Also termed the upper plastic limit . See also Atterberg Limits, Plastic Limit, Plasticity Number. Light non-aqueous phase liquid. See Non-aqueous Phase Liquid. 

Marl ll 2, 4, 8, 10, 20, 40 (natural ground barite for coatings and plastics, number refers to particle size)... 

Plasticity Number The difference between the liquid limit and the plasticity limit of a soil or similar material (9, 10). Also termed the plasticity index. See also Atterberg Limits, Liquid Limit, Plastic Limit. 

Municipality Plastics Number of Collected Curbside Pickup Collectra Households Stan of Plastics Collection Number of Dropoff Centers... 

Typically, recycling collection companies sort the plastics into clear bottles and containers (number 1), opaque bottles (number 2), and colored bottles and plastics (numbers 3 through 7). The recycled plastic bottles and containers are crushed and then placed in pallets and shipped to MRF. 

For Bingham slurries a nondimensional coefficient is defined as the plasticity number ... 

The Hedstrom number is the product of the plasticity number and the Reynolds number and is calculated as... 

And the Plasticity number is written in terms of the hydraulic radius as... 

Atmospheric pressure Plasticity number Wetted perimeter Radius... 

One of the early works to describe fabrication of fibers fi om polyvinylidene fluoride was published in 1965.In this work, the authors demonstrated the relationship between molecular weight and the strength of oriented fiber. An empirical index called plasticity number was defined as an indication of the molecular weight of polymer. A threshold range for the plasticity number was defined that yielded good fiber properties. 

The plasticity number was defined as the area (in mm ) of a fihn that was formed from 0.5 g PVDF in a press under specified conditions. The resin was piled in a cone between the platens of a press heated to 225°C. The platens were closed together to compress the powder under minimal pressure for 30 seconds to allow it to be heated. Pressure was raised to 17.3 MPa for 60 seconds during which a film formed on the platen. After cooling, the area of the PVDF film was measured. The lower the molecular weight of PVDF, the lower its melt viscosity and the higher the area over which the molten polymer spread and formed film. 

Figure 8.37 Yield (Y) and break stress (B) of polyvinylidene fluoride vs stretch temperature (plasticity number of...

The sensitivity of the plastic properties upon concentration have even induced Atterberg to introduce certain specified concentrations as a measure of the plasticity of clays. A clay is characterized by its plastic number, which is the diflFerence between the "dipper and " lower plastic limits . The upper plastic limit is the moisture content at which the yield stress just becomes measurable. At the moisture content corresponding to the lower plastic limit, the yield stress is so high that the day has lost its plastic deformability. 

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