Metal finishing Q&As since 1989

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Pmma authenticity test

2004

Hey all!

I machine stainless and other "bio-safer" materials and recently purchased some polymethly methacrylate, or so I have been told. The material seems to act different that other pieces of pmma I have, and I am suspicious that the material is not pmma, but pmmc (polymethly methylchloride) or some other plastic. Is there a test to confirm the item is methylmethacrylate? Any help is greatly appreciated!

Thanks!

Jeff Swayze
owner /operator /machinist,etc... - Kelowna, B.C., Canada

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Properties of PMMA (Polymethyl Methacrylate) such as Lucite® and Plexiglas® are given at www.matweb.com. Click on "Material Type" then under "Thermoplastic Polymers" select "Acrylic". I've never heard of a methyl chloride polymer ˜ perhaps you mean vinyl chloride. Comparing unfilled PMMA to rigid, unfilled PVC, the PMMA is clearer (transmits 92 % of visible light) and less dense (1.15-1.19 g/cc vs. 1.3). Also, PMMA burns relatively cleanly, while PVC emits an acrid black smoke containing hydrochloric acid.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2004