Laboratory of Polymer Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands; Sasol Technology R and D, 1 Klasie Havenga Street, Sasolburg, South Africa; Department of Polymer Science and Chemistry, University of Stellenbosch, Matieland, South Africa
Norah Maithufi, M., Laboratory of Polymer Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands, Sasol Technology R and D, 1 Klasie Havenga Street, Sasolburg, South Africa; Joubert, D.J., Sasol Technology R and D, 1 Klasie Havenga Street, Sasolburg, South Africa; Klumperman, B., Laboratory of Polymer Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands, Department of Polymer Science and Chemistry, University of Stellenbosch, Matieland, South Africa
Statistical comb-type copolymers of styrene (Sty) and stearyl methacrylate (C18 MA) with varying [styrene]:[C18MA] ratios were synthesized by a controlled/living radical polymerization technique called atom transfer radical polymerization. The polymeric materials were evaluated in selected SASOL Fischer Tropsch gas-to-liquid diesels as possible cold flow improvers. Crystallization studies revealed that as the styrene content of the copolymer increased, a crystal growth inhibition mechanism was exhibited. With an increase in styrene content of the copolymer, differential scanning calorimetry and the cloud filter plugging point (CFPP) revealed a delay in onset of crystallization and lowered CFPP, respectively, whereas low-temperature microscopy indicated modifications and size reduction of wax crystals. However, there appeared to be a styrene content, beyond which the additive's efficiency decreased. Homopolymer and copolymers with the highest styrene content led to long unfavorable needle-shaped crystals. © 2011 Wiley Periodicals, Inc.
Cold filter plugging point; Cold flow improver; cold flow properties; Comb-type copolymer; Controlled/living radical polymerization; Crystal growth inhibition; Filter plugging; Fischer Tropsch; GTL diesel; Low temperatures; Size reductions; Stearyl methacrylate; Wax crystals; Copolymers; Crystal growth; Diesel fuels; Differential scanning calorimetry; Polymerization; Styrene; Atom transfer radical polymerization