Download - CHM 585/490
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CHM 585/490
Chapter 20
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Soaps and Bulging Drum Case Story
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Soaps
• Contain both a hydrophilic (water loving) end and a hydrophobic (water repelling) portion.
• Hydrophilic end is the carboxylate salt
• Hydrophobic end is the aliphatic end
• U.S. soap & detergent industry about $10 billion
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Saponification
O
O
(CH2)nCH3
O
O
(CH2)nCH3
O
O
(CH2)nCH3
H2C
HC
H2C
NaOH
O
O
(CH2)nCH3
O
O
O
H2C
HC
H2C
H
H
H
H
O
O
(CH2)nCH3H
O
O
(CH2)nCH3H
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Fats
• Tallow- beef by-product; most commonly utilized animal fat in the processing of soaps
• Coconut Oil – from the dried fruit of the coconut tree
• Palm kernal oil – from palm tree nuts
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Percentage of Acids from Different Fats
Tallow Coconut Palm kernal
Lauric C12 50 50
Myristic C14 3 18 18
Palmitic C16 27 8.5 8
Stearic C18 20 3 2
Oleic C18 unsaturated
43 6 14
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Soap
• RCO2- Na+ Typical soap
• RCO2- K+ Soft soap
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Cationic SurfactantsQuats
O
O
(CH2)nCH3H H2N
O
(CH2)nCH3
NH3C (CH2)nCH3N
H2C (CH2)nCH3H2N
CH3ClH2C (CH2)nCH3N
CH3
CH3
H3C+
Cl-
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Synthetic Detergents
• RSO3- Na+
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Hypothesis IResidual ethylene oxide was
degassing from the ethoxylated alcohol during storage at elevated
temperatures
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ROH O
linear alcoholR = C12 - C14
ethylene oxide
+ x R(OCH2CH2)xOH
ethoxylated alcoholx = 0-6
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Headspace GC
• No ethylene oxide detected
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Hypothesis 2
• Ethoxylated alcohol was breaking down via auto-oxidative mechanism in the presence of oxygen, elevated temperatures and trace metals
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Summary
• Wet chemical Analyses – Degradation products not detected
• GC – product quality good• Atomic Absorption
– Fe 0.5ppm– Co 0.6 ppm – Ni < 3 ppm
• Headspace GC – no differences detected
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Conclusions
• Residual ethylene oxide is not the source of explosive gas
• Auto-oxidative breakdown of ethoxylated alcohol is not producing a problem
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Hypothesis 3
• Breakdown of a stabilizer (sodium borohydride) is causing the explosive gas
• BH4- + 4H2O B(OH)4
- + 4 H2
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Conclusions
• Gas in headspace was hydrogen
• Breakdown of stabilizer to produce hydrogen was responsible for the bulged drums and results from excessive water in the product
• Recommend that borohydride be removed from the product
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U.S. Detergent Market
40%
8%5%8%
7%
6%
5%
21%
Tide (P&G) (40%)
Gain (P&G) (8%)
Cheer (P&G) (5%)
Purex (Dial) (8%)
All (Unilever) (7%)
Arm & Hammer(Church and Dwight)(6%)
Wisk (Unilever) (5%)
Other (21%)
C&E News 1/26/04
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VP R&D for detergents at Procter & Gamble?
• Guess who?
• Dr. Grime
• I’m not making this up!
• (C&E News 1/26/04)
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Many Ingredients (such as)
• Bleaching Compounds• Builders• Enzymes• Suds suppressors• Brighteners• Softeners (clays)• Dye Transfer Inhibiting Agents• Surfactants• Fragrances
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Bleaching Compounds
• Percarbonates often used:
O
O
O O O
R R
O
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Bleaching Compounds
S
O
O
O OO
C9H19
Used in Tide and Gain
C &E News 1/26/04
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Builders
To assist in controlling mineral hardness and
to assist in the removal of particulate soils.• Liquid formulations typically comprise from
5% to 30%, by weight, of detergent builder.• Granular formulations typically comprise from
15% to 50% by weight.
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Builders
• Often alkali metal silicates, particularly those having a SiO2:Na2O ratio in the range 1.6:1 to 3.2:1
• Zeolites (aluminosilicates) also commonly used
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• Enzymes can be included in the formulations for a wide variety of fabric laundering purposes, including removal of protein-based, carbohydrate-based, or triglyceride-based stains.