Block Copolymers of Styrene and Stearyl Methacrylate. Synthesis and Micellization Properties in Selective Solvents

Abstract

Block copolymers of styrene and stearyl methacrylate were prepared using anionic polymerization high-vacuum techniques by sequential addition of monomers. Narrow molecular weight distribution copolymers of different molecular weight and composition were obtained. The molecular characteristics of the copolymers were obtained by size exclusion chromatography, membrane osmometry, low-angle laser light scattering (LALLS), and differential scanning calorimetry. Comparative studies in the selective solvents for the polystyrene block, ethyl and methyl acetate, showed that mainly unimolecular micelles are formed in the former, whereas larger aggregates are observed in the latter solvent. LALLS, viscometry, and dynamic light scattering were used to characterize the micelles.

Model linear and star-shaped polyisoprenes with phosphatidylcholine analogous end-groups. Synthesis and association behavior in cyclohexane

“…This effect has been previously observed in associating and micellar systems. [17,35,36] Similar conclusions can be drawn for the telechelic polyisoprenes regarding the [Z], R v , and k H values. However, direct comparison with the star structure cannot be applied in this case, due to the presence of two end-zwitterion groups per polymer chain and the existence of equilibrium between intra-and intermolecular association.…”

Synthesis and solution rheology of poly[(stearyl methacrylate)-stat-([2-(methacryloyloxy)ethyl] trimethyl ammonium iodide)]

“…Because the presence of SMA segments confers a strongly crystalline character on the polymer, it can be debated whether the polymer has long segments of SMA or if the SMA is randomly distributed. The melting temperature of the stearyl methacrylate polymers decreased much more rapidly than was reported for block co-polymers of SMA and styrene [21]. T m strongly decreases with increasing amount of DMAEMA and T g decreases.…”

Structural and thermal behavior of comb‐like polymer having n‐octadecyl side chains

“…9 Somehow the crystallization of long alkyl groups in side chain polymers might be seen as a crystallization of alkanes in the presence of external constrains. The crystallization behavior of long alkyl groups in side chain polymers has been studied by different techniques [10][11][12][13][14] and it is known that the alkyl groups in the substance can crystallize at room temperature. Otherwise, the constrains by the methacrylate backbone are still remarkable so that only one-third of the CH 2 units in the alkyl group can crystallize easily.…”