Cologne Making 1

CHM144L – B11

Experiment info:

Date: 16 Aug 2012

e-mail: [email protected]

Mapúa Institute of TechnologySchool of Chemical Engineering, Chemistry, Biological Engineering and Materials Science Engineering

Cologne MakingDe Jesus, Medarlo1 Romero. Von Joby M. 2

1Professor, School of Chemical Engineering, Chemistry, Biological Engineering and Materials Science Engineering, Mapua Institute of Technology; 2Author, Student, CHM144L/B11, Industrial Chemistry Laboratory, School of ChE-Chm BT, Mapua Institute of Technology

Graphical Abstract

A.

B.

Keywords: cologne, vaporization, vehicles, isolates, esterification, oxidation

Introduction

Fragrances are products that make a major contribution to the cosmetic industry, as well as to the production of soaps and detergents. These products are industrially useful in masking, neutralizing, and altering the odor of various products. It can provide additional crating aroma for normally odorless products.

The history of perfumes can be traced back to the ancient Egyptians. The earliest form of perfume was incense (See Figure 1), which gives off a strong odor when burned. The word perfume comes from the Latin words per fumum, meaning "through smoke."

Figure 1. Ancient Egyptian incense

Plants are the sources of substances called essential oils, which gives plants their distinctive odor. These oils may come not only from petals but also from the bark,

CHM144L – Romero, Von Joby M. 2009102874 1 of 5

Comparison Cologne[a] Fragrance

[b] Persistence- Cold T.

- Room T.

[1] Vehicle [2] Odorous substance

[3] Water

Isolates- smell comparison

-appearance

Reagents

EsterificationOxidation


seeds, leaves and roofs of a certain plant. Common plant sources include sandalwood, rosemary, jasmine, cinnamon, roses, and among others (See Figure 2).

Figure 2. Essential oils from plants

Meanwhile, animals secrete substances that are valuable to perfume industry. These animal products are called fixatives, which makes the fragrances last longer by preventing the essential oils from vaporizing too rapidly. Among these products includes castor from the beaver, civit from civit cat, and musk from musk deer.

Due to high raw material cost, alternative materials were used by synthetically producing compounds that are capable of duplicating the scent and function of natural materials. Perfume, nowadays, are combination of natural, synthetic chemicals, alcohol and water. Composition is important factor in producing fragrances because it determines the quality of the product. This is the basis of general classification for odoriferous products (See Table 2).

Each perfume is composed of a so-called top note, middle note and base note. The top note is the odor that you perceive immediately. The middle note is the heart of the perfume and that really defines its characters; the most persistent note is the base. Say in Eternity (Figure 3), the top note consists of freesia and sage; middle note includes marigold, jasmine and rose while the base note is made up of sandalwood, musk and amber. The mixture of different essence creates the character of the perfumes.

Figure 3. Eternity perfume

Theoretical Discussion

Basically, fragrances have three basic constituents – vehicle, fixatives and odorous substances. The most common solvent or vehicle, used for holding and blending fragrances, is highly refined ethyl alcohol (C2H5OH). It can contain substantial amount of water depending on the solubility of the oil employed. The odour of the vehicle must be removed to avoid odour interference with the fragrant product. Meanwhile, fixatives are substances that have lower volatility compared to odorous oils. It can retard and even up the rate of evaporation of various odorous constituents. These odorous constituents give the significant scent to the fragrance, and are generally categorized as essential oils, isolates and synthetic or semi-synthetic chemicals. The function of the constituent in the fragrance is summarized in Table 1.

Table 1. Fragrance constituentsConstituent Function1

Vehicle Projects the scent it carries which are inert to the solute and is not irritating to skin

Fixatives Retard or even up the rate of oil evaporation

Odorous substances Gives scent and identity to the fragrance product

As presented in Table 2, fragrances are categorized based on the concentration of odorous substances it contains.

Table 2. Fragrance categoryCategory Odorous substance

concentration (% wt/wt)Cologne splash 3%Cologne 5%Toilet water (eau de toilet)

8%

Eau de perfume 15%Perfume 30%

Generally, key compositions of fragrance are highly volatile. Thus, change in condition such as pressure and temperature changes would adversely affect the product. At high temperature, the rate of volatilization of essential oil can be altered. It may produce unfamiliar smell that can decrease the quality value of the product.

In this experiment, the effect of varying the amount of alcohol, essential oil and fixative used on preparing cologne was determined. The effect of temperature on the quality of cologne prepared was also obtained. Finally, synthetic preparation of isolates was also done.

Experimental Result

1 Austin, G.T., 1984, Shreve’s Chemical Process Industries. 5th edition. McGraw-Hill: USA



The following result was obtained based on the conducted experiment (presented in Tables 3-5).

Table 3. CologneCologne

FormulationOdor Appearance

C1(2) Mild cool water scent

Clear liquid

C2(1) Strong cool

water scentBlurred

C3(3) Mild cool water scent

Clear liquid

Table 4. Cologne stored in the refrigerator2

Cologne Formulatio

n

Fragrance Persistence (hours)

Effect on

Skin Fabric

C1

(2) Mild cool

water scent

(1) Cool and refreshing

Leaves a spot

C2

(1) Strong cool

water scent


Leaves a spot

C3

(3) Mild cool

water scent


Leaves a spot

Table 4. Colognes stored at room temperatureCologne

Formulation

Fragrance Persistence (hours)

Effect on

Skin Fabric

C1

(2) Mild cool

water scent


Leaves a spot

C2

(1) Strong cool

water scent


Leaves a spot

C3

(3) Mild cool

water scent


Leaves a spot

Table 5. Odorous substance

ReactantCharacteristic odor evolved

Compound responsible for

the odorEthyl alcohol, acetic acid,

H2SO4

-Sour fruit-like odor

Ethyl acetate (ethyl

ethanoate)

Amyl alcohol, acetic acid, sulfuric acid

-Banana odor -Slightly more pleasant than

C1 mixture

Amyl Acetate

Potassium dichromate, Sulfuric acid, Ethyl alcohol

-Fruity odor, plastic balloon

odorAcetic Acid

Discussion

2 Persistence: (1) longest time, (2) middle, (3) shortest time

In the first part of the experiment, cologne was prepared through mixture of various fragrance components, namely the odorous substance (Happy(M) Type), ethyl alcohol, and water (See Figure 4).

Figure 4. Components of laboratory-prepared cologne

The concentration of each component in the mixture was varied in order to observe the alteration occurred and the effect of each as presented in Table 6.

Table 6. Cologne formulationCologne

Formulation

%wtAlcohol

% wtEssential

Oil

%wtWater

C-1 60.0 3.0 36.50C-2 40.0 3.0 56.50C-3 60.0 2.0 37.50

The said components were weighed using the digital balance with a basis of 50 g (See Figure 5). Then, the materials were thoroughly mixed in the 150 mL beaker using glass stirrer. After stirring, it was equally divided into two. One part was used for low temperature storage while the other for room temperature storage. It was then sealed in 300 mL PET bottles to avoid volatilization of essential oils.

Figure 5. Weighing of components in the mixture

As observed, essential oil was put first in the mixture, followed by the alcohol, then water. It was done at



decreasing volatility. This was to prevent exposing the most volatile component to atmospheric pressure, having a tendency to vaporize readily.

Upon evaluation of odor and color, it was obtained that C-2 formula has the strongest scent among the three, which also showed different color (cloudy white). It was because C-2 contains the highest essential oil concentration, 3 wt/wt%. However, C-1 formulation also contains the same concentration of essential oil compared with C-2. In this case, alcohol-water ratio as observed, were different. C-2 formula contains more water than alcohol. The effect of more alcohol is that, it can suppress the odor of essential oil it carries by competing with its smell. Water, on the other hand, acts as a diluter in the mixture, which also can minimize the odor. Also, upon comparing the ratio of essential oil to vehicle (alcohol) ratio, it can be obtained that C-2 formulation has higher magnitude, thus stronger pleasant odor can be produced.

Meanwhile, the color of the mixture for C-2 is cloudy white, unlike with C-1 and C-3. This was because C-2 contains less alcohol which acts as an emulsifier between the water and the oil (hydrophobic). Due to lack of alcohol, the mixture becomes less miscible (See Figure 6).

Figure 6. C1 to C3 cologne formula mixture (from left to right)

For comparison, both colognes prepared at cold and room temperature produced the same odor, however they differed in persistence. Cologne stored in cold temperature (T=277 K) has higher persistence because low temperature condition prevents essential oil to vaporize. Note that volatile substance vaporizes faster at higher temperature (T=298 K), at the same pressure.

As applied to skin, both colognes prepared at different temperature were not reactive, and did not irritate the skin. It was due to substances for the colognes used were not irritant and incapable of producing violent effect on human skin. On the other hand, for the fabric application, all colognes left a spot which probably due to impure mixture.

Meanwhile, on the second part, synthetic organic essential oils called isolates were synthesized through esterification and oxidation of different reagents which includes C2H5OH, HOAc, amyl alcohol, H2SO4 and K2Cr2O7, as seen in Figure 7.

Figure 7. Reagents used in Part B experiment

The first formulation (C1) was synthesized with the use of C2H5OH, HOAc and H2SO4. Upon esterification, the reactants had undergone the reaction equation as given in equation 1, to form ethyl ethanoate, compound responsible for the fruity-like odor (pear-drop smell characteristic). This key product is also used in nail polish removers and glues. However, trace sour smell was observed due to unreacted acetic acid.

[1]

The reactant has colorless appearance, similar to the characteristics of the product as well as the unreacted reactants as indicated (See Figure 8).

Figure 8. Three isolates synthesized in lab: ethyl acetate, amyl acetate and acetic acid (from left to right)

For the second reaction, amyl alcohol, HOAc and H2SO4

reacted via esterification process to form amyl acetate (See Equation 2). This product gives off more



pleasantly fruit-like odor (banana smell), compared to the first. This product is usually used in coatings, as extraction solvent in pharmaceuticals and leather polishes. From the batch solution, the components formed layers, suggesting that either of the reactants and the products is immiscible.

[2]

Finally, the third reaction as seen in equation 3, involves reactants namely, C2H5OH, K2Cr2O7 and H2SO4. It undergoes reaction strong oxidation with the sulfuric acid to form aldehyde, acetaldehyde and further to carboxylic acid, acetic acid.

[3]

The reactant starts off by producing an overall orange pigment solution, which is due to added K2Cr2O7. Upon contact with ethyl alcohol vapor in the presence of heat, the solution turned green, an indication that aldehyde formed. This solution gave off fruity like smell, due to acetaldehyde. It further oxidizes to acetic acid, indicated by blue pigment of the solution. At this point, the fruity smell was lessening gradually due to masking of vinegar smell of acetic acid. Although sour smell was not observed, gradual change in the original smell indicated that HOAc formed.

Conclusion

In this experiment, cologne was successfully prepared at different concentration using varied concentration of main constituent of fragrance namely, the vehicle, odorous substance and water.

It was learned that cologne has least amount of odorous substance, as for its concentration in the mixture ranges about 2-3% wt/wt.

Factors affecting the quality of cologne include the composition of the cologne itself. Higher concentration of essential oil essentially leads to higher cologne fragrance. On the other hand, vehicle (commonly ethyl alcohol) can mask or interfere with the fragrance, leading to less concentrated smell, although it can improve persistence. Water, also reduces the strength of fragrance because it acts as the diluter, producing cheaper but lesser fragrance quality.

For temperature, colognes stored at colder temperature was proved to last longer than stored at room temperature. By the virtue of temperature dependence of vapor pressure, essential oils can readily vaporize at higher temperature (T=298 K) than at lower temperature (T=277 K) at the same pressure (atmospheric pressure).

Finally, isolates which are synthetically produced organic compounds were successfully prepared using reagents which undergoes either esterification or oxidation. Different products namely ethyl acetate, amyl acetate, and acetaldehyde and ethyl alcohol produce different smells, which are both appealing and unappealing to humans.


Cologne Making 1

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