Styrene-Butadiene Rubber by Miniemulsion Polymerization Using In Situ Generated Surfactant

Abstract

<jats:p>An alternative approach for the synthesis of styrene butadiene rubber (SBR) copolymer latexes was explored in order to obtain low gel fractions and high solid contents. The ultra-turrax-assisted miniemulsion stabilized by in situ surfactant generation was adopted as the main strategy since this technique can inhibit the eventual presence of secondary nucleation producing polybutadiene particles and also control the cross-linking degree. Styrene monomer was first miniemulsified using an ultra-turrax and in situ generated surfactant using either hexadecane (HD) or octadecyl acrylate (ODA) as the hydrophobe. Dynamic light scattering (DLS) measurements of droplet size indicated faster stabilization and the production of smaller droplet diameters ca. 190 nm (PdI = 0.08) when employing in situ generated potassium oleate (K-Oleate) in comparison to SDS-based miniemulsions. High butadiene-level SBR latexes with ca. 50% solids content, a glass transition temperature (Tg) of −52 °C, and a butadiene to styrene weight ratio of 75:25, were then obtained using the miniemulsion droplets as seeds. Turbiscan and DLS measurements revealed a very stable resulting latex with SBR particle diameter of ca. 220 nm and a low polydispersity index (PdI). Secondary nucleation was prevented as indicated by the low Np/Nd value. Cryo-TEM images showed a narrow distribution of particle size as well as the absence of agglomeration. The gel content was below 10% when tert-dodecyl mercaptan (t-DM) was used as chain transfer agent (CTA).</jats:p>

Synthesis of styrene butadiene copolymer via novel nanoemulsion based system

“…The small size of emulsifier droplets with large surface area leads to effective capture of free radicals generated in the aqueous phase and hence the higher rate of reaction observed. [ 25,44,45 ]…”

“…The process of the nanoemulsion polymerization gives distinct polymerization kinetics due to the presence of a higher number of reactive sites and the rate of reaction also becomes faster in the nanoemulsion process. [ 44 ]…”

“…The process of the nanoemulsion polymerization gives distinct polymerization kinetics due to the presence of a higher number of reactive sites and the rate of reaction also becomes faster in the nanoemulsion process. [44] Because of the presence of a greater number of reactive sites, a greater number of polymer chains grows simultaneously. When a greater number of active molecules are there, more chance of chain termination happens to achieve reaction stability.…”

“…The small size of emulsifier droplets with large surface area leads to effective capture of free radicals generated in the aqueous phase and hence the higher rate of reaction observed. [25,44,45] The latex obtained from nanoemulsion is comparatively viscous. The particle size analysis of latex obtained from nano-and macroemulsion compared.…”

A comprehensive review of the recent developments in thermoplastics and rubber blends‐based composites and nanocomposites

“…These traits make SBR suitable for manufacturing seals integrated into hydraulic brake systems, cutting boards, gaskets, shoe soles, and so forth. [17][18][19][20] Butyl rubber, called isobutylene isoprene, is considered unique because of its gas impermeability and excellent flexibility. These characteristics allow for the application of butyl rubber in the production of airtight sports balls, inner tubes, and sealants.…”