If you like us, please share us on social media, tell your friends, tell your professor or consider building or adopting a Wikitext for your course.

ChemWiki: The Dynamic Chemistry Hypertext > Under Construction > Demonstrations > Additional Demos > The Preparation of Bakelite

The Preparation of Bakelite

Chemical Concept Demonstrated

  • Thermoset plastics


Formaldehyde is added to the beaker inside a fume hood.

Aniline hydrochloride (C6H5NH3Cl) is rapidly added.



The polymer expands out of the beaker, along with a prodigious amount of heat.


This reaction is highly exothermic, but that is not why the plastic produced is referred to as "thermoset".

Bakelite is a space-network polymer. Unlike linear and branched polymers, which are composed of long molecules that make them more or less crystalline, space-network polymers are highly and irregularly cross-linked throughout the structure. The sheer extent of the cross-linking means that a sample of the material is essentially one gigantic molecule.

Although heat softens and melts linear and branched polymers, heating does not soften space-network polymers because such a softening would require the breaking of covalent bonds.  In fact, heating usually produces additional cross-linking in these polymers, making them harder.  It is for this reason that space-network polymers, such as bakelite, are called thermoset plastics.



You must to post a comment.
Last modified
10:31, 2 Oct 2013



(not set)
(not set)
(not set)






This material is based upon work supported by the National Science Foundation under Grant Numbers 1246120, 1525057, and 1413739.

Creative Commons License Unless otherwise noted, content in the UC Davis ChemWiki is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License. Permissions beyond the scope of this license may be available at copyright@ucdavis.edu. Questions and concerns can be directed toward Prof. Delmar Larsen (dlarsen@ucdavis.edu), Founder and Director. Terms of Use