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The main polycarbonate material is produced by the reaction of bisphenol A (BPA) and phosgene COCl 2. The overall reaction can be written as follows: The first step of the synthesis involves treatment of bisphenol A with sodium hydroxide, which deprotonates the hydroxyl groups of the bisphenol A. [6] (HOC 6 H 4) 2 CMe 2 + 2 NaOH → Na 2 (OC 6 ...
FRP tanks and vessels designed as per BS 4994 are widely used in the chemical industry in the following sectors: chlor-alkali manufacturers, fertilizer, wood pulp and paper, metal extraction, refining, electroplating, brine, vinegar, food processing, and in air pollution control equipment, especially at municipal waste water treatment plants and water treatment plants.
Although single layer polycarbonate sheeting is more flexible than polycarbonate in twinwall configuration, it still retains significant advantages over alternative materials, including glass. A typical 6mm sheet has a density of 0.72 g/cm^2 [ 6 ] and a thermal insulation R value of 0.3 m^2°C/W, while allowing 80% of visible light pass through ...
The ultrasonic density meter calculates the sonic velocity by using the known distance between the transmitter and receiver and the measured transit time. The measuring instrument can now calculate the density, as it is dependent on the sound velocity. [3] Another method that is utilized in ultrasonic meters is the envelope energy average method.
Barcol hardness is measured on a scale from 0 to 100 with the typical range being between 50B and 90B. A measurement of 60B is roughly equivalent to a Shore hardness of 80D or a Rockwell hardness M100. [4] [6] As defined in ASTM D 2583 the scale divisions from 0-100 should each indicate a depth of 0.0076 mm or the equivalent 0.0003 inches. [7]
ASTM D1434 - Standard Test Method for Determining Gas Permeability Characteristics of Plastic Film and Sheeting; ASTM D3079 - Standard Test Method for Water Vapor Transmission of Flexible Heat-Sealed Packages for Dry Products; ASTM D4279 - Standard Test Methods for Water Vapor Transmission of Shipping Containers-Constant and Cycle Methods
Conductivity based TDS meter in a cup of water. The two principal methods of measuring total dissolved solids are gravimetric analysis and conductivity. [4] Gravimetric methods are the most accurate and involve evaporating the liquid solvent and measuring the mass of residues left. This method is generally the best, although it is time-consuming.
Imbibition methods, [6] i.e., immersion of the porous sample, under vacuum, in a fluid that preferentially wets the pores. Water saturation method (pore volume = total volume of water − volume of water left after soaking). Water evaporation method (pore volume = (weight of saturated sample − weight of dried sample)/density of water)