Senior Research Scientist
Dr. Misdrahi is currently responsible for managing application development, and technical service for use of NOVELUTION additives in paints, coatings, and inks at Sasol R&D in Lake Charles, LA. He holds a Ph.D. in polymer science and engineering from Lehigh University, and he is been in the industry for more than 25 years. He has held different positions as technical manager, Sr. applications chemist, and marketing manager for several international corporations, including Hercules (Nowadays Ashland), Air Products, and Brenntag. Author and co-author of 7 published technical articles and presenter at 15 technical conferences at the international level. Dr. Misdrahi is currently developing new additives for coatings with a focus on customer needs and environmental demands.
Novel Branched Surfactants Improving Color Properties in Architectural Coatings
Color strength and color acceptance are the two main attributes when an architectural coating is formulated; compatibility between the tint and paint is critical to achieving a great performance when the paint is applied by roller, brush or spray, and for its final appearance. A family of novel branched APEO-free surfactants at different HLBs were evaluated, studying different paint properties, including color strength and color acceptance. Five APEO-free tints: one carbon black, one inorganic, and three organic pigments were tested. For this comparison, white paint of pigment volume concentration (PVC) of 50%, with an APEO-free 100% acrylic latex, was formulated using a combination of associative and non-associative thickeners. An alkyl phenol ethoxylate (APEO) of 9 moles was taken as a standard to be compared. Our results show that novel high branch ethoxylate surfactants provide better compatibility and color strength probably because they are acting as co-dispersants. Polyoxyethylene oxide groups are hydrated, forming a layer that provides steric stabilization. The novel branched surfactant structure shows that adsorption is facilitated more than micellization.