A novel process for obtaining controlled morphologies in polymer blends is modeled numerically. Particles of one type of polymer are allowed to dissolve in a matrix of a dissimilar polymer. Prior to complete dissolution the blend is quenched into the two-phase region, such that phase separation takes place. The combination of the incomplete dissolution and the wavelength selection process assoc...

Mixtures of ideal polymers with hard spheres whose diameters are smaller than the radius of gyration of the polymer, exhibit extensive immiscibility. The interfacial tension between demixed phases of these mixtures is estimated, as is the barrier to nucleation. The barrier is found to scale linearly with the radius of the polymer, causing it to become large for large polymers. Thus for large po...

We present a study of flow-induced phase transitions in microemulsion phases of ternary polymer blends. The results match qualitatively with the recent experimental observations on such systems but differ from the behavior expected and observed in the analogous system of surfactants. We rationalize this contrast from a molecular viewpoint suggesting that the interplay between polymer chain conf...

5.1 Chapter Summary Bicomponent fibers, in the range of 100 nm to a few microns, of miscible poly(vinylchloride)/segmented polyurethane (PVC/Estane) and immiscible poly(vinyl chloride)/poly(vinylidienefluoride) (PVC/PVDF) were produced respectively by electrospinning two polymer solutions in a side-by-side approach. For each of the pairs investigated, PVC/Estane and PVC/PVDF, energy dispersive ...

Incorporation of liquid crystalline polymers (LCPs) into commodity polymers remains a challenge in the design of high-performance, low-cost polymeric blends. Blends of a thermoplastic polymer and a nematic LCP are produced here by mechanical alloying. Functionality sensitive X-ray microscopy reveals LCP dispersions as small as 100 nm in diameter. Intimate mixing remains upon subsequent melt pro...

A b s t r w A series of blends at molecular level dispersion between an organic polymer and metal oxide (mainly silica) are described. These blends are called "organicinorganic polymers hybrids". The dimension of dispersion of "hybrids" is much smaller than that of the so-called "composites". The most suitable organic polymers for the formation of hybrids are those which consist of repeating un...

This review provides a comprehensive assessment on polymer blends and nanocomposite systems for articular cartilage tissue engineering applications. Classification of various types of blends including natural/natural, synthetic/synthetic systems, their combination and nanocomposite biomaterials are studied. Additionally, an inclusive study on their characteristics, cell responses ability to mim...

The dynamic dilution theory of stress relaxation, quantitative for star polymer melts, cannot be directly applied to star-linear blends. The linear chains on their reptation time scale τd release constraints on the star arms, resulting in constraint-release Rouse motion for the star arms not described by dynamic dilution. We present a microscopic theory without adjustable parameters for stress ...

Immiscible homopolymers are often blended mechanically to obtain blends with properties significantly superior to those of the component polymers. The creep recovery of such blends was studied in the previous paper, henceforth referred to as I. Surface-active compatibilizers are commonly added to such blends to improve blending of the immiscible phases and to improve the mechanical properties o...

The objective of this study was to determine if a high Tg polymer (Eudragit(®) S100) could be used to stabilize amorphous domains of polyethylene oxide (PEO) and hence improve the stability of binary polymer systems containing celecoxib (CX). We propose a novel method of stabilizing the amorphous PEO solid dispersion through inclusion of a miscible, high Tg polymer, namely, that can form strong...