Poly(alkyl acrylates), such as poly(lauryl acrylate), are widely used in coatings, adhesives, and enhanced oil recovery, among others, because of their hydrophobic and viscoelastic properties. Conventional batch free radical polymerization of lauryl acrylate (LA) is constrained by poor heat and mass transfer, resulting in polydisperse product, inefficient initiator utilization, and environmental concerns. This study addresses these challenges by employing a helically coiled flow microreactor (HCFM) to achieve precise control and sustainability in LA polymerization. We evaluated the effects of initiator type and concentration, reaction temperature and residence time on monomer conversion, molecular weight distribution and polydispersity index (PDI) and developed a kinetic model to predict reaction pathways. Experiments were conducted in a continuous-flow PTFE capillary system using initiators such as azobis(isobutyronitrile) (AIBN), and products were characterized using gel permeation chromatography. AIBN generated the highest number-average molecular weight of ≈37,800 g/mol, whereas dimethyl azobis(isobutyrate) produced the narrowest PDI of ≈1.05. Under optimal conditions (AIBN molar ratio 0.1–0.25, reaction temperature 60–70 °C, and residence time 240–400 s), conversions reached 85%–90% with PDIs as low as 1.05. A power-law kinetic model accurately captured the sub-first-order behavior, attributed to enhanced mixing through Dean vortices. These findings demonstrate the superiority of HCFMs over batch methods, yielding uniform polymers while reducing energy consumption (by 50%–70%) and waste generation, thereby enabling scalable, green polymer production for industrial applications.
Tang et al. (Wed,) studied this question.