The Most Effective Model for Describing the Universal Behavior of a Noisy Kuramoto–Sivashinsky Equation as a Paradigmatic Model

We study a noisy Kuramoto–Sivashinsky (KS) equation which describes unstable surface growth and chemical turbulence. It has been conjectured that the universal long-wavelength behavior of the equation, which is characterized by scale-dependent parameters, is described by a Kardar–Parisi–Zhang (KPZ) equation. We consider this conjecture by analyzing a renormalization-group equation for a class of generalized KPZ equations. We then uniquely determine the parameter values of the KPZ equation that most effectively describes the universal long-wavelength behavior of the noisy KS equation.     

New methodology for synthesizing polyolefinic graft block copolymers and their morphological features

This paper describes a new synthetic route for polyolefinic graft block copolymers by adopting coupling reaction between terminally hydroxylated polyolefins and maleic anhydride grafted polyolefins. Terminally hydroxylated polypropylene (PP-OH) was coupled with maleic anhydride modified polyethylene (PE-g-MAH) and such ethylene-propylene random copolymer (EPR-g-MAH) to give polyolefinic graft block copolymers (PE-g-PP and EPR-g-PP, respectively). The formation of PE-g-PP was confirmed by enhancement on molecular weight and it brought about distinctive decrease in size of dispersed domain in its phase separation morphology. Occurrence of coupling reaction to give EPR-g-PP was indicated by extreme decrease in its solubility to n-decane and it led to unique morphology demonstrating lamella microstructure that had never been reported for a comparable polyolefin composite.     

Polymacromonomers with polyolefin branches synthesized by free-radical homopolymerization of polyolefin macromonomer with a methacryloyl end group

Polymacromonomers with polyolefin branches were successfully synthesized by free-radical homopolymerization of polyolefin macromonomer with a methacryloyl end group. Propylene-ethylene random copolymer (PER) with a vinylidene end group was prepared by polymerization using a metallocene catalyst. Then, the unsaturated end group was converted to a hydroxy end group via hydroalumination and oxidation. The PER with the hydroxy end group was easily reacted with methacryloyl chloride to produce methacryloyl-terminated PER (PER macromonomer; PERM). The free-radical polymerization of thus-obtained PERM was done using 2,2′-azobis(isobutyronitorile) (AIBN) as a free-radical initiator. From NMR analyses, the obtained polymers were identified as poly(PERM). Based on gel permeation chromatography (GPC), the estimated degree of polymerization (D_p) of these polymers were about 30. Thus, new class of polymacromonomers with polyolefin branches was synthesized.     

Free radical polymerization within mesoporous zeolite channels

Free radical polymerization of methyl methacrylate (MMA) within the uniform channels of the mesoporous zeolite MCM-41 proceeds at 100°C to give a high molecular weight polymer (PMMA). The formation of long-living propagating polymer-radicals is observed by electron paramagnetic resonance (EPR). The molecular weight of PMMA within the mesopores can be controlled over a wide range by changing the monomer-to-initiator mole ratio.     

Characterizing the universal rigidity of generic tensegrities

Mathematical Programming - A tensegrity is a structure made from cables, struts, and stiff bars. A d-dimensional tensegrity is universally rigid if it is rigid in any dimension $$d'$$ with...