(131b) Role of Initiator & Surfactant in Multi-Stage Core-Shell Polymer Aqueous Agglomeration & Powder Properties

A multi-factor analysis study was performed on the effects of surfactant choice—sodium c14-16 alpha olefin sulfonate vs. sodium lauryl sulfate—and initiator choice—potassium peroxydisulfate (KPS) vs. tert-butyl hydroperoxide (tBHP)—on the temperature of agglomeration and product bulk density of two variants of acrylic processing aids—the K‑128P innovation product PMMA1 and one of our established processing aids PMMA2. The goal of the experimental work was to enhance the final product performance of a newly launched acrylic processing aid product designed for rigid PVC applications.

After initial development and customer sampling, challenges were uncovered related to the product powder production, packaging, and product conveying experience at the customer. This series of studies focused on resolving the two overarching parameters: I) Lowering the temperature of agglomeration and II) Increasing the bulk powder density in the final packaged product. These were selected out of a range of desirable scaleup improvements such as high foaming in the wastewater, high dust-loss during drying, high temperature needed for agglomeration and bulk powder density below that expected of our comparable processing aids.

The study concluded that emulsion polymers of the processing aid family respond to changes in surfactant & synthesis initiators in the parameters studied (I & II). As a result, the new product was modified with the optimal composition and improved isolation techniques proved effective at mitigating all of the manufacturing concerns identified during early scaleup, enabling reliable plant-scale production of the innovation product in the year since the changes have been implemented. The product has closed production gaps with our existing portfolio without compromising the innovative properties of the new chemistry.