Hello alanhatt,
The two main ingredients in Crayola crayons are paraffin, stearic
acid, and coloring pigment. According to the How Stuff Works site,
"Crayons melt at 105 degrees Fahrenheit (40 degrees Celsius). I would
be extremely cautious about melting crayons in the microwave, however,
as microwave heating is an uneven process! See this article from the
University of Queensland, and at least consider placing the tubes in a
standing up postion, in a water bath. Keep the tubes away from you
face when removing them from the microwave!:
http://www.uq.edu.au/ohs/pdf/alert-paraffin.pdf
Apparently Binney & Smith Crayolas have been found so safe, that they
are not required to complete MSDS(Material Safety Data Sheets) on
them.
http://intranet.risd.edu/envirohealth_msds/Crayola/CrayolaCrayons.pdf
However, this Havasu, Arizona School page is not happy about the
lack of MSDS, and says melting crayons can emit toxic fumes:
http://www.havasu.k12.az.us/support/warehouse/rossol.html
This article, while not directly related to your project, suggests
making a mark with a crayon before heating. You and your child could
make a mark on the outside of the test tube, one for each color.Stand
the tubes up, in a water bath...when the mark melts and slides down,
you have reached the melting point! This method seems much safer, as
it involves such a small quantity of crayon.You can have "Crayon
Melting Races" to see which color melts off first!
http://www.omega.com/temperature/Z/pdf/z197.pdf
The formula of Crayola crayons is a closely guarded secret! "The
Crayola crayons of today are made by essentially the same formula as
that of the original crayons made in 1903. Improvements and minor
adjustments have, of course, taken place over the past 90 years, but
the crayon formula is as guarded today as it was then." From OptiMall
http://www.optimall.org/family/entertainment/cj/crayola.htm
Guideposts for Kids
http://www.gp4k.com/frontpage/Article.asp?ID=743
This How Stuff Works site explains the melting point of crayons.
http://entertainment.howstuffworks.com/question563.htm
Some Crayola Chemistry, from American Chemistry
http://www.americanchemistry.com/chemmag.nsf/WebMagazineArticle?ReadForm&mfik-4s9jyq
Extra Information:
A Color Timeline of Crayola Colors:
http://www.factmonster.com/ipka/A0872797.html
The History of Crayola Crayons
http://inventors.about.com/library/inventors/blcrayon.htm
From The Glass Ceiling:
http://www.theglassceiling.com/supermoms2/su9_how.htm
For a very basic explanation of how crayons are made:
http://www.crayola.com/factory/preview/factory_floor/crayon_mfg.htm
From the MadSci Network:
http://www.madsci.org/posts/archives/feb2002/1014235571.Ot.r.html
Hope you found the information you needed for your project! If any
part of my answer is unclear, please request an Answer Clarification,
before rating. This will allow me to assist you further, if possible.
Regards,
crabcakes-ga
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