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Sunday, August 18, 2019

Novel Paint Formulation II (Watercolor/ Modified Lanolin /Synthetic Petrolatum)

I am conducting chemical research on novel paint formulations for artists.

In this experiment, I conducted base-promoted (saponification) of lanolin in glycerol betweeen 165-185 deg. over 30 minutes.
It is anticipated that complete saponification should occur under these conditions in about 30 minutes.
4.0 g sodium hydroxide dissolved in glycerol at 120-130 deg cCin about 15 minutes to yield a bright yellow solution.

The temperature of solution was brought to about 155 deg C (+/- 5 degrees) 
25 g lanolin (Fisher Scientific) was added over 30 seconds to the stirred solution of glycerol.
The temperature reached about 180-185 deg c over 30 minutes. A transition in color, viscosity , solubility occurs over this time period. The final appearance is a brown (soap) appearance and is homogeneous at this termperature.

The solution was stirred while the temperature was allowed to drop to about 60-70 deg C over  30 minutes.

At this point , the material is a viscous semi-solid. Additional cooling would afford the soap.

10% H2SO4 was added slowly and stirring continued to bring the soap to a beige-tan emulsion.  The PH should be 1-2.

When virtually no solid soap particles are observed, the solution is cooled to ambient temperature.
The beaker contents are transferred to a blender, water added to desired viscosity and blending conducted for 2-3 minutes.
A more viscous emulsion was obtained vs. the results in my previous post.
The soap can be subjected to acetone extraction over 6 hours to separate the fatty alcohols from the fatty acid sodium carboxylates.  We will obtain a GC/MS on the acetone extract and compare with the cake extract from conditions described in the prior upload /

The modified lanolin emulsion ( saponified/ acidified in aq. acid/ glycerol) was blended with an inexpensive commercial watercolor (red hue) and 'synthetic petrolatum' (previous upload preparation) along with a small amount (spatula tip) of 'Gold Bond Foot Powder' ( contains talcum, acacia extract and zinc oxide among other components; it does help with brush flow).
Stirring for 15 -30 seconds affords a nice paint formulation.
I applied the paint with bristle / flat brushes to watercolor paper (140 lb).

Next experiment: The use of oil-based paint to form the emulsified paint formulation.
Above: emulsified modified lanolin/ a synthetic petrolatum ( from renewables) and commercial red watercolor.

Above: The sodium hydroxide at the point of solubility in the glycerol.

Above: The lanolin has been added and saponification starts.
For a short period of time , a precipitate is observed but goes back in solution as the reaction progresses. The solution becomes a darker amber.

The  heat is shut down and the reaction cools from 170-185 Deg.C.  At 55-75 Deg C, the 10% H2SO4 is added in small portions and reaction stirred for at least 30 minutes. The cooled emulsion is placed in a blender for smooth homogenation before use in paint formulation.

The emulsion starts breaking after 48 hrs at 20 deg C:


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