Compatibilization of Polymer Blends

Most polymer blends are immiscible and need to be compatibilized. The compatibilization must accomplish: (i) optimization of the interfacial tension, i.e., the degree of dispersion; (ii) stabilize the morphology against high stresses during forming, and (iii) enhance adhesion between the phases in the solid state. Compatibilization is accomplished either by addition of a compatibilizer or by reactive processing. The presentation will focus on the fundamental aspects, viz. description of the interphase, compatibilization by addition and reactive compatibilization.Peer reviewed: NoNRC publication: Ye

Compounding Multi-phase Polymeric Systems

Peer reviewed: NoNRC publication: Ye

Rigid ballistic composites (Review of literature)

Peer reviewed: NoNRC publication: Ye

PNC polymeric nanocomposites : Fundamentals & technology

Peer reviewed: NoNRC publication: Ye

Preface (to special issue dedicated to memory of Prof. Robert Simha)

Peer reviewed: NoNRC publication: Ye

Robert Simha

Peer reviewed: NoNRC publication: Ye

Rheological Properties of Different Nanocomposites Based on Polyamide-6

Peer reviewed: NoNRC publication: Ye

Polystyrenes with macro-intercalated organoclay. Part I: Compounding and Characterization

Nanocomposites of polystyrene (PS) were prepared using a melt compounding or co-solvent method. Two commercial PS were used, and two organoclays—one prepared in this laboratory (COPS), and the other commercial Cloisite® 10A (C10A). The COPS is a product of clay intercalation with a copolymer of styrene and vinyl benzyl tri-methyl ammonium chloride. According to the XRD diffraction data, the clay platelets in COPS and its PNC with PS were relatively well dispersed, i.e. with the interlayer spacings of d001=7–8 nm. By contrast, d001 in PNC prepared with C10A was only 4 nm. However, the number of clay platelets per stack in PS/COPS was found to be significantly larger than that in PS/C10A, viz. m=3–12, compared to m=2–6. The scanning and transmission electron microscopy indicated that in the PS matrix COPS existed in form of large, immiscible domains

Polystyrenes with macro-intercalated organoclay. Part II: Rheology and Mechanical Performance

Polymeric nanocomposites (PNC) of polstyrene (PS) with organoclay were studied for their rheological and mechanical behavior. The organoclay (COPS) is a product of clay quaternization with a copolymer of styrene with vinyl benzyl tri-methyl ammonium chloride. PNC preparation and characterization was described in Part I of this paper. The clay platelets in COPS and its PNC\u27s are well dispersed, i.e. with the interlayer spacings of d001=7–8 nm. By contrast, d001=3–4 nm for PNC with Cloisite® 10A. However, the COPS in PS formed large, deformable domains. At concentration exceeding 5.8-wt% of COPS, the domains started to form a three-dimensional network with enhanced elasticity and progressive viscoelastic non-linearity. At temperatures of 160–180 °C the neat COPS did not flow; its behavior resembled that of a crosslinked elastomer. Application of the time–temperature superposition led to master curves of bending moduli vs. 19 decades of reduced frequency. The curves indicated a transition at ca. 180 °C, most likely associated with the disintegration of ammonium ion clusters. With the same amount of clay the mechanical properties of PNC with COPS were slightly worse than those with Cloisite® 10A—the immiscibility of COPS, and the presence of extractable (by the matrix) low molecular weight compounds explain the behavior