Tertiary amines, such as DABCO, are often used as catalysts in the production of polyurethane foams that react polyols with isocyanates. Screening catalyst formulations is easy by measuring the height and consistency of the rate of foam rise after adding the isocyanate to a mixture of polyol, catalyst and blowing agent (e.g., pentane, not CFC) in a metal cup. Each catalyst system has advantages and disadvantages.
A patent issued this month (Burdeniuc, J.; Panitzsch, T.; Dewhurst, J.; (Evonik Degussa GmbH) US Patent 9,890,236, 13-Feb-2018) compares various catalysts for polyurethanes, including dimethyl diallyl ammonium pivalate with classical DABCO catalysts (tertiary amine). This quat salt gave consistent foam rise at a good rate similar to or better than the standard DABCO catalysts typically used, but quat salts are not volatile and therefore do not suffer from odors from tertiary amines such as DABCO. Diallyl dimethyl ammonium chloride is a low molecular weight quat salt (more moles per kg) made from inexpensive raw materials and the chloride is easily exchanged for pivalate, a sterically hindered carboxylate (an important factor of this invention).
Contact Marc Halpern of PTC Organics when you need help choosing a phase-transfer catalyst for a commercial PTC application.
About Marc Halpern
Dr. Halpern is founder and president of PTC Organics, Inc., the only company dedicated exclusively to developing low-cost high-performance green chemistry processes for the manufacture of organic chemicals using Phase Transfer Catalysis. Dr. Halpern has innovated PTC breakthroughs for pharmaceuticals, agrochemicals, petrochemicals, monomers, polymers, flavors & fragrances, dyes & pigments and solvents. Dr. Halpern has provided PTC services on-site at more than 260 industrial process R&D departments in 37 countries and has helped chemical companies save > $200 million. Dr. Halpern co-authored five books including the best-selling “Phase-Transfer Catalysis: Fundamentals, Applications and Industrial Perspectives” and has presented the 2-day course “Practical Phase-Transfer Catalysis” at 50 locations in the US, Europe and Asia.
Dr. Halpern founded the journal “Industrial Phase-Transfer Catalysis” and “The PTC Tip of the Month” enjoyed by 2,100 qualified subscribers, now beyond 130 issues. In 2014, Dr. Halpern is celebrating his 30th year in the chemical industry, including serving as a process chemist at Dow Chemical, a supervisor of process chemistry at ICI, Director of R&D at Sybron Chemicals and founder and president of PTC Organics Inc. (15 years) and PTC Communications Inc. (20 years). Dr. Halpern also co-founded PTC Interface Inc. in 1989 and PTC Value Recovery Inc. in 1999. His academic breakthroughs include the PTC pKa Guidelines, the q-value for quat accessibility and he has achieved industrial PTC breakthroughs for a dozen strong base reactions as well as esterifications, transesterifications, epoxidations and chloromethylations plus contributed to more than 100 other industrial PTC process development projects.
Dr. Halpern has dedicated his adult life to his family and to phase-transfer catalysis (in that order!).
