Blends of Polypropylene and Syndiotactic 1,2-Polybutadiene: Morphology, Crystallization Behaviors and Mechanical Properties

Morphologies, crystallization behavior and mechanical properties of polypropylene(PP)/syndiotactic 1,2-polybutadiene(s-1,2 PB) blends were investigated. Morphology observation shows the well dispersed domains of s-1,2 PB in PP matrix with the rather small domain sizes from 0.1 to 0.5 mu m when the s-1,2 PB content increases from 5% to 20% (mass fraction) in the blends, and the phase structure tends to become co-continuous as s-1,2 PB content further increases.

Topological Diversity of Coordination Polymers Containing the Rigid Terephthalate and a Flexible N,N'-Type Ligand: Interpenetration, Polyrotaxane, and Polythreading

Reactions of zinc(II) or cadmium(II) salts with terephthalic acid (H(2)tp) and 1,3-bis(4-pyridyl) propane (bpp) have afforded four coordination polymers at room temperature, [Zn(mu-tp)(mu-bpp)](n)center dot 2nH(2)O (1), [Cd-2(mu-tp)(2)(mu-bpp)(3)](n)center dot 2nH(2)O (2), [Cd(mu-tp)(mu-bpp)(H2O)](n)center dot nH(2)O (3), and [Cd-2(mu-tp)(mu-bpp)(2)(bpp)(2)Br-2](n) (4). Single-crystal X-ray diffraction has revealed interesting topological features for these compounds.

The study of banded spherulite patterns by coupled logistic map lattice model

Banded spherulite patterns are simulated in two dimensions by means of a coupled logistic map lattice model. Both target pattern and spiral pattern which have been proved to be existent experimentally in banded spherulite are obtained by choosing suitable parameters in the model. The simulation results also indicate that the band spacing is decreased with the increase of parameter mu in the logistic map and increased with the increase of the coupling parameter epsilon, which is quite similar to the results in some experiments. Moreover, the relationship between the parameters and the corresponding patterns is obtained, and the target patterns and spiral patterns are distinguished for a given group of initial values, which may guide the study of banded spherulite.

Molecular weight dependence of phase Behavior of PEO/P(EO-b-DMS) blends: Application of Sanchez-Lacombe lattice fluid theory

Molecular weight dependence of phase separation behavior of the Poly (ethylene oxide) (PEO)/Poly(ethylene oxide-block-dimethylsiloxane) (P(EO-b-DMS)) blends was investigated by both experimental and theoretical methods. The cloud point curves of PEO/P(EO-b-DMS) blends were obtained by turbidity method. Based on Sanchez-Lacombe lattice fluid theory (SLLFT), the adjustable parameter, epsilon*(12)/k (quantifying the interaction energy between different components), was evaluated by fitting the experimental data in phase diagrams. To calculate the spinodals, binodals, and the volume changes of mixing for these blends, three modified combining rules of the scaling parameters for the block copolymer were introduced.

Rheology, morphology and mechanical properties of compatibilized poly(vinylidene fluoride) (PVDF)/thermoplastic polyurethane (TPU) blends

Compatibilized blends of poly(vinylidene fluoride) (PVDF) and thermoplastic polyurethane (TPU) were developed using maleated PVDF (PVDF-g-MA). Excellent compatibilization between PVDF and TPU was demonstrated by theological, morphological, and mechanical measurements. The introduction of PVDF-g-MA into the PVDF/TPU blends caused an increase in viscosity and storage modulus. Much finer morphology was clearly observed by SEM. The tensile tests showed that the tensile strength and ultimate elongation achieved a significant improvement with addition of PVDF-g-MA.