Donald Witenhafer
S.C. Johnson and Son
Inducted 2009
Donald Witenhafer (1940 – 2013) was a polymer chemist whose innovations in PVC polymerization are numerous and helped eliminate the issues and hazards related to residual vinyl chloride monomer in PVC. He earned a B.S. degree in Chemical Engineering from the Case Institute of Technology in 1962. After learning that Eric Baer was starting a Polymer Engineering and Science program, he returned to Case, earning both M.S. and Ph.D. degrees. Upon graduation, he joined B. F. Goodrich as a Research and Development Scientist at their Avon Lake, OH campus. He eventually became Research and Development Manager.
In 1969, the management of B. F. Goodrich and others recognized that vinyl chloride monomer (VCM) was a likely human carcinogen. Goodrich initiated a project called “Code Zero” dedicated to eliminating issues related to human exposure to VCM. At the time, Witenhafer was a PVC polymerization research and development scientist. While more than 130 engineers and scientists were on the Code Zero team, Witenhafer’s role on the team was critical because of his extensive knowledge of PVC polymerization reactions. Witenhfer was a co-inventor of several breakthrough innovations as part of this effort that helped save the PVC industry. These included ways to remove residual VCM from PVC and water-based reactor vessel coatings that eliminated the need for manual cleaning of the reactors and the related human exposure to the VCM.
There had also been some concern that VCM could be released during melt processes such as blow molding or extrusion, some thought due to possible depolymerization. Witenhafer and the team were able to show that any VCM given off during processing was due to residual monomer from the polymerization process, not depolymerization due to process heat. Eliminating the residual monomer would solve the problem of VCM release during melt processing. The method he developed for removing the residual monomer from the PVC polymerization slurry was to use a steam stripping column and vacuum. The polymerized resin slurry flows through a series of trays while steaming, and the stripped residual monomer exit the top of the column. This method allowed for the production of PVC with a residual monomer content below one part per million. Goodyear shared the greener polymerization process with other PVC manufacturers.
Don Witenhafer left Goodrich in 1986 to become the Manager of Polymer Development and Pioneering Research at S.C. Johnson and Son in Racine, WI. Throughout his career, Donald was active in professional societies. He was an Honored Service Member and Fellow of the Society of Plastics Engineers (SPE). He also served as a Councilor for the Engineering Properties and Structures Division of SPE and the SPE South Texas Section Board of Directors. He Chaired the Houston, TX Polyolefins Conference. He was a member of the Polymer Industrial Advisory Boards of the University of Connecticut and the University of Southern Mississippi.
Areas of Expertise:
Plastics materials