TOC flash points

The flash point most often quoted for oxygenated solvents is the Taghabue (Tag) Open Cup or TOC flash point while for hydrocarbons the Tag Closed Cup or TCC flash point is more commonly used. When hydrocarbon and oxygenated solvents are mixed together, the TOC flash point is generally the one chosen to characterize the blend. The main concern here will be that of predicting TOC flash points for solvent blends from the flash points of the individual components. 

For hydrocarbon fractions there are established correlations between TCC flash point and boiling range (6,7). In the present work a review of TOC flash point data for oxygenated solvents shows a relatively good correlation (standard deviation of 5%) between log (component vapor pressure at 25°C) and flash point. Correlation between flash point and boiling point proved to be less satisfactory. 

Table I. Solvent Blend TOC Flash Points Comparison Between Published Flash Points, Redetermined Flash Points, and Flash Points Calculated by the Sum of Indexes Method0...

Blend Published Data TOC Flash Point, Redetermined TOC Flash Points, Component TOC Flash Point, Calculated TOC Flash Point,... 

The accuracy of predicting mixture flash points depends strongly on the validity of the pure component flash point data which are used in the calculation procedure. There is, for example, little published data for TOC flash points of hydrocarbons. Some of the accepted TOC flash point data for oxygenated solvents were unreliable, e.g., the TOC flash point acetone is often quoted as 15°F this was redetermined in the present work at — 20°F. Component flash points shown in Table III were generally taken from published flash point data and were not checked experimentally. 

Table III. Comparisons Between Sets of TOC Flash Point Data From Different Sources...

Contains 15% n-propyl alcohol and has no TOC Flash Point below its boiling point of 180°F. 

There are no generally accepted specifications manufacturers set their own specifications for hydroxyl number range, melt viscosity, water content, etc. Typical properties of Du Pont Terathane PTMEG are Hsted in Table 2, and selected thermal properties are given in Table 3 (260). For all grades, water content is <0.015 wt % ash, <0.001 wt % iron, <1 ppm peroxide, <5 ppm as H2O2 and flash point TOC is >163°C. 

Flash Point is given in degrees Celsius, usually using a closed cup. When the method is known, the acronym appears in parentheses after the value closed cup (CC), Cleveland closed cup (CCC), open cup (OC), Tag closed cup (TCC), and Tag open cup (TOC). Because values will vary with the specific procedure employed, and many times the method was not stated, the values listed for the flash point should be considered only as indicative. See also Table 5.23, Properties of Combustible Mixtures in Air. 

Flash Point (flash p). This is the lowest temperature at which a liquid will give off enough flammable vapor at or near its surface such that in intimate mixture with air and a spark or flame it ignites. The flash point of liquids is usually determined by the Standard Method of Test for Flash Point with the Tag Closed Cup Tester (ASTM D56-52, available from the American Society for Testing Materials, 1916 Race St, Philadelphia, Pa). This method is also the standard of the American Standards Association (ASA Z 11.24-1952, available from the American Standards Association, 70 East 45th St, New York, NY). The Interstate Commerce Commission uses the Tag Open Cup (TOC) Tester giving results 5—10°F higher (less flammable). Other methods frequently used are... 

TOC. Abbreviation for Tagliabue open cup, a standard method for determining flash points. 

TEN tensile strength (usually Ts) TOC tangliabue open cup (flash point)... 

Tag Open Cup (TOC). A standard method of determining flash points. 

The following abbreviations are used to describe the method that was used for the data included in the field Flash point CC - closed cup, CCTC - closed cup tag closed, COC -Cleveland open cup, OC - open cup, PMCC - Pensky-Martens closed cup, TCC - tag closed cup, TOC - tag open cup... 

Specific Gravity 25C 1.05 Flash Point (TOC) 127C Molecular Weight 220... 

Appearance White to Off-White Powder Flash Point(TOC) 260C Melting Point Range 170C-180C Molecular Weight 697... 

Appearance Clear viscous liquid Viscosity 0 25C 5,200 cps Color-Gardner 2 Specific Gravity Flash Point (TOC)... 

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