Palmitic acid, alias Hexadecanoic acid is a saturated higher fatty acid that widely exists in nature. Almost all oils contain varying amounts of palmitic acid component.
The main component of palmitic acid is from Oils from palm trees, namely palm oil and palm kernel oil; butter, cheese, milk and meat all contain this fatty acid; industrially, it is saponified from animal fats such as butter and lard or vegetable oils such as palm kernel oil. Prepared; Palmitic acid anion is the observed form of palmitic acid in physiological pH. The content of palmitic acid in tallow oil from tallow seeds produced in China can be as high as more than 60%, that in palm oil is about 40%, and that in rapeseed oil is less than 2%.
The specific physical properties are as follows:
1. Structural formula: C15H31COOH
2. Molecular mass: 256.42;
3. Characteristics: White pearlescent scales;
4. Density (g/mL, 25/4℃): 0.8527;
5. Relative density: 0.835 (62/4℃);
6. Melting point (oC): 63;
7. Boiling point (oC, normal pressure): 351;
8 . Boiling point (oC, 13.3kPa): 267;
9. Refractive index (n60D): 1.43345;
10. Refractive index at room temperature (n20): 1.430970;
11. Refractive index at room temperature (n25): 1.427280;
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12. Gas phase standard combustion heat (enthalpy) (kJ·mol-1): -10132.4;
13. Gas phase standard claims heat (enthalpy) (kJ· mol-1): -737.2;
14. Liquid phase standard heat of combustion (Enthalpy) (kJ·mol-1): -10031.1;
15 . Liquid phase standard claims heat (enthalpy) (kJ·mol-1): -838.5;
16. Standard heat of combustion (enthalpy) of crystalline phase (kJ·mol-1): -9977.96;
17. Crystal phase standard claims heat (enthalpy) (kJ·mol-1): -891.48;
18. Crystal phase standard entropy (J·mol-1·K-1): 452.37;
19. Crystal phase standard formation free energy (kJ·mol-1): -315.10;
20. Lower explosion limit (%, V/V): Undetermined;
21. Solubility: Insoluble in water, slightly soluble in cold alcohol and petroleum ether, easier to dissolve when heated , soluble in ethanol, easily soluble in ether, chloroform and acetic acid, only 0.00072g dissolved in 100ml of water;
22. Flash point (oC): >110. </span