New Emulsion SBR Technology: Part I. Raw Polymer Study

Abstract

Emulsion styrene—butadiene rubber (ESBR) has been the workhorse of the tire industry since World War II. With the development of solution polymers, ESBR has seen a steady decrease in its use in tire applications. A novel ESBR has been developed which imparts some of the rheological behavior previously only observed in solution polymers. This new ESBR was prepared by blending a high molecular weight elastomer with a low molecular weight elastomer, each having a unique styrene-butadiene composition. A two-phase co-continuous morphology was observed by scanning probe microscopy when the bound styrene difference between the two components was greater than 18%, consistent with the two glass transition temperatures measured by thermal analysis. Blending also served to reduce the amount of very high molecular weight material (> 107 g/mol) readily observed in 1502- and 1712-type polymers by thermal field flow fractionation (ThFFF). ThFFF was found to be superior to size exclusion chromatography for fully characterizing the molecular weight and molecular weight distribution of the polymers. Time—temperature superposition was performed to characterize the viscoelastic behavior in the rubbery plateau and terminal zones. The ESBR blends showed a cross-over in the terminal flow region that was not observed in 1502- and 1712-type polymers.

Novel Methods of Producing Low-Reflectance Coatings Utilizing Synergistic Effects of Polymer Phase Separation

“…Thermal characterization of the coating was performed with differential scanning calorimetry (DSC) to determine the glass transition of the cross-link polymer network. DSC analyses of the pigmented film showed three distinct glass transition temperatures in the derivative plot, 81.1, 153.2, and 185.6 °C, as seen in Figure , indicating phase separation as seen in prior reports and the possibility of three distinct polymer domains . The presence of two high-temperature transitions observed in the DSC signified a possible strong interaction between the additives (pigments and matting agent) and the high- T g polymer localized near the additive/polymer interface.…”

Sustainable Myrcene-Based Elastomers via a Convenient Anionic Polymerization

“…In the rubber industry, excluding natural rubber (NR), polybutadiene (BR) and styrene-butadiene rubber (SBR) are the two main products [ 45 , 46 ], these latter are produced on a large scale from emulsion (E-SBR) [ 47 , 48 ] and solution (S-SBR) [ 49 ] polymerization. S-SBR is synthesized by an anionic polymerization process, which is initiated by organolithiums compounds, such as sec-butyl lithium (sec-BuLi) or n -butyl lithium ( n -BuLi), soluble in common organic solvents.…”

Field Flow Fractionation for the Size, Molar Mass, and Gel Content Analysis of Emulsion Polymers for Water‐Based Coatings

“…Most frequently, these polymers are synthesized by free radical emulsion polymerization . Emulsion polymers are well established in various fields including styrene‐butadiene rubbers (SBR) in the automotive industry, amphiphilic polymers in food technology and core shell particles in drug delivery systems . Typical emulsion systems for water‐based coatings contain styrene, acrylic monomers, and crosslinking agents.…”

“…As no stationary phase is present, filtering of the samples is not required and the soluble and gel containing fractions of the complex samples can be analyzed without problems. Thermal FFF (ThFFF) has been used for analysis of SBR emulsions, while sedimentation FFF (SdFFF) has extensively been used to characterize particle size distributions of colloidal species . Striegel and co‐workers have measured the particle size and shape distribution of colloidal species using hydrodynamic chromatography .…”

“…in the automotive industry, amphiphilic polymers in food technology and core shell particles in drug delivery systems. [2][3][4] Typical emulsion systems for water-based coatings contain styrene, acrylic monomers, and crosslinking agents. The chemical heterogeneity of an emulsion can be signifi cant and molecular properties like the fi nal chemical composition and the molar mass distribution are of high importance for the fi nal coating properties.…”