This work presents new results on using organoclay with an appropriate polymeric compatibilizer as rheology-modifying additives for extrusion foaming of a linear polypropylene (PP), which by itself does not display strain hardening in extensional flow of the melt. The uniaxial melt-extensional viscosity behavior of several nanocomposites prepared with varying ratio of bound maleic anhydride to ...

In this paper the relationship between molecular structure and behavior of the LDPE melt is discussed from a scaling perspective on the bases of results from GPC-MALLS analysis. Long chain branches introduce a characteristic length scale that marks a transition in rheology behavior of the melt with decreasing length scale of deformation i.e. with increasing process rate or decreasing temperatur...

The feasibility of fabricating polypropylene (PP) nanofibers has been explored by using different additives, such as sodium oleate (SO), poly(ethylene glycol) (PEG) and poly(dimethyl siloxane) (PDMS), during melt electrospinning. PP of high melt flow index (1000) was used with PEG and PDMS for the reduction of the melt viscosity; and it was used with SO for improving the electrical conductivity...

To determine the role of surface tension-driven melt migration in planetary bodies, we investigated the effect of static annealing on the evolution of melt-rich bands in partially molten samples. In shear deformation experiments, deviatoric stress causes melt to segregate; when the stress is removed, surface tension causes the melt to relax back to a homogeneous distribution. Samples composed o...

Accelerated ice flow near the equilibrium line of west-central Greenland Ice Sheet (GIS) has been attributed to an increase in infiltrated surface melt water as a response to climate warming. The assessment of surface melting events must be more than the detection of melt onset or extent. Retrieval of surface melt magnitude is necessary to improve understanding of ice sheet flow and surface mel...

Polymers are known to exhibit various flow instabilities during extrusion in which a molten polymer is forced to flow through a narrow die, in order to form a strand or acquire a desired shape of the final product. Recent developments in experimental techniques revealed that some of the instabilities are interfacial in nature, that is originate from the violation of the no-slip boundary conditi...

Ethiopia is a region where continental rifting gives way to oceanic spreading. Yet the role that pre-existing lithospheric structure, melt, mantle flow, or active upwellings may play in this process is debated. Measurements of seismic anisotropy are often used to attempt to understand the contribution that these mechanisms may play. In this study, we use new data in Afar, Ethiopia along with le...

A theoretical study is presented of the effect of a radially converging melt flow, which is directed away from the solidification front, on the radial solute segregation in simple solidification models. We show that the classical Burton-Prim-Slichter (BPS) solution describing the effect of a diverging flow on the solute incorporation into the solidifying material breaks down for the flows conve...

In this second installment of a series that aims to investigate the dynamic interaction between the composition and abundance of the solid mantle and its melt products, the classic interpretation of fractional melting is extended to account for the dynamic nature of the process. A multiphase numerical flow model is coupled with the program AlphaMELTS, which provides at the moment possibly the m...