The complex viscosity of planar star-branched polymers has been derived from general rigid bead-rod theory, but only for singly-beaded arms. Here, we explore the respective roles branch functionality, arm length, and nonplanar arrangements, analytically theory. For nonplanar, include polyhedral, both regular irregular. Further, all structures, compare with without central bead. We fit theory to...

Dielectric and mechanical spectroscopy methods have been employed to describe the temperature dependencies of the segmental and macromolecular relaxation rates in epoxy/hydroxy functionalized polybutadiene. Dielectric studies on the dynamics of segments of the polymer as well as the mobility of small ions trapped in the system have been carried out both as a function of temperature and pressure...

Micellar solutions of polystyrene-block-polybutadiene and polystyrene-block-polyisoprene in propane are found to exhibit significantly lower cloud pressures than the corresponding hypothetical nonmicellar solutions. Such a cloud-pressure reduction indicates the extent to which micelle formation enhances the apparent diblock solubility in near-critical and hence compressible propane. Concentrati...

The influence of confinement on the steady-state morphology of two different emulsions is investigated. The blends, made from polybutene (PB) in polydimethylsiloxane (PDMS) and polybutadiene (PBD) in PDMS, are sheared between two parallel plates, mostly with a standard gap spacing of 40 microm, in the range of shear rates at which the transition from "bulk" behavior toward "confined" behavior i...

Employing Molecular Dynamics simulations of a chemically realistic model of 1,4-polybutadiene between graphite walls we show that the mass exchange between layers close to the walls is a slow process already in the melt state. For the glass transition of confined polymers this process competes with the slowing down due to packing effects and intramolecular rotation barriers.

The postpolymerization modification by hydroformylation of 1,2-polybutadiene nanoparticles provides access to colloidally stable aqueous dispersions of <20 nm particles. Their polarity can be adjusted via the degree of conversion of double bonds over a broad range. Fluorescence studies illustrate the polarity of the environment experienced by pyrene as a probe molecule.

In this paper, we use a combination of experiment and simulation to achieve enhanced levels synthetic control on the microstructure much-used binder material hydroxyl terminated polybutadiene (HTPB).

Local dynamics of polyethylene and 1,4-trans-polybutadiene chains are analyzed by the cooperative kinematics approach. The method includes the effects of environmental friction and the conformational energy changes involved in bond rotational motions. A given bond is rotated by 120° and the response of the surrounding bonds along the chain, which are necessary for localizing the motion, are ana...