The key difference between double and triple pressed stearic acid is that the triple pressed stearic acid is more refined than the double pressed stearic acid.
Stearic acid is a saturated fatty acid. It is a solid waxy compound. The chemical formula of this compound is C17H35CO2H. Further, the esters and salts of stearic acid are stearates. The double pressed and triple pressed stearic acid are two commercial grades of stearic acid.
CONTENTS
1. Overview and Key Difference
2. What is Double Pressed Stearic Acid
3. What is Triple Pressed Stearic Acid
4. Side by Side Comparison – Double vs Triple Pressed Stearic Acid in Tabular Form
5. Summary
What is Double-Pressed Stearic Acid?
Double pressed stearic acid is a commercial grade of stearic acid which is less refined than triple pressed stearic acid. In other words, double pressed stearic acid have impurities and unwanted substances than triple pressed form. However, the double pressed form is still available in the market, although it is not common.
Figure 1: Appearance of Stearic Acid
In general, the properties of this commercial-grade depend on the manufacturer. Some important properties of double pressed stearic acid are as follows (according to the Tradeasia International pte ltd.):
- Acid value = 209.0 – 215.0 mgKOH/g
- Saponification value = 210 – 215 mgKOH/g
- Titer = 52 – 55°C
- Iodine value = maximum 4 gI2/100 g
Applications of Double Pressed Stearic Acid
| Rubber and plastics | Rubber vulcanization, tyre production, making surfactants and plasticizers, etc. |
| Soaps and detergents | Manufacture of soaps, shampoo, shaving cream, detergents, etc. |
| Food industry | Production of margarine, creamy spreads, bakery products, soft drinks, etc. |
| Other | Candle production, grease production, etc. |
What is Triple-Pressed Stearic Acid?
Triple pressed stearic acid is a modern commercial grade of stearic acid. It is well refined to remove the impurities and unwanted compounds. In fact, it is purer than double pressed stearic acid. Some important properties of this commercial grade are as follows:
- Acid value = 207.0 – 212.0 mgKOH/g
- Saponification value = 208 – 213 mgKOH/g
- Titer = 54 – 56.5°C
- Iodine value = maximum 0.5 gI2/100 g
Applications of Triple Pressed Stearic Acid
| Food and beverage | Used as a hardener for candies |
| Lubricants | As a thickener in greases, as a mold releasing lubricant, etc. |
| Rubber and plastics | As a viscosity depressant in plastics and as an accelerator and activator in rubber processing. |
| Personal care | As an emulsifier, in the production of detergents and soaps, etc. |
What is the Difference Between Double and Triple Pressed Stearic Acid?
Double vs Triple Pressed Stearic Acid |
|
| Double pressed stearic acid is a commercial grade of stearic acid which is less-refined than triple pressed stearic acid. | Triple pressed stearic acid is a modern commercial grade of stearic acid which is highly-refined. |
| Purity | |
| Comparatively, less pure | Purer, when comparing both stearic acids |
| Iodine Value | |
| When comparing both, the iodine value is very high | Comparatively, very low |
Summary – Double vs Triple Pressed Stearic Acid
Stearic acid is a saturated fatty acid compound. It is available in two major commercial grades as double pressed form and triple pressed form. The key difference between double and triple pressed stearic acid is that the triple pressed is more refined than the double pressed. Therefore, the triple pressed is purer and contains a very low iodine value than the double-pressed.
Reference:
1. “Stearic Acid (Double Pressed Grade).” Tradeasia International Pte Ltd.
2. “Stearic Acid.” Wikipedia, Wikimedia Foundation, 26 Apr. 2018, Available here.
3. “Triple Pressed Stearic Acid | CAS 57-11-4.” Acme-Hardesty, Available here.
Image Courtesy:
1. “Stearinsäure auf Uhrglas” By Gmhofmann – Own work (CC BY-SA 3.0) via Commons Wikimedia