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The interphase boundary of incompatible polymer blends such as poly(methyl methacrylate)(PMMA)/natural rubber(NR) and polystyrene(PS)/NR, and of compatible blends such as PMMA/NR/epoxidized NR(ENR) and PS/NR/styrene–butadiene–styrene(SBS) block copolymer, where ENR and SBS were used as compatibilizers, was studied by means of microindentation hardness(H) and microscopy. Cast films of neat PMMA and PS, and blended films of PMMA/NR, PS/NR, PMMA/NR/ENR, and PS/NR/SBS were prepared by the solution method using a common solvent(toluene). Hardness values of 178 and 173 MPa were obtained on the surfaces of the neat PMMA and PS, respectively. After the inclusion of soft phases, the binary(incompatible) and the ternary(compatible) blend surfaces show markedly lower H-values. Scanning electron and optical microscopy reveal a clear difference at the phase boundary of the surface of compatible(smooth boundary) and incompatible(sharp boundary) blends. The compatibilized blends were characterized by using microhardness measurements, as having the thinnest phase boundary(∼30 µm), while incompatible blends were shown to present a boundary of about 60 µm. The hardness values indicate that the compatibilizer is smoothly distributed across the interface between the two blend components. Results highlight that the microindentation technique, in combination with microscopic observations, is a sensitive tool for studying the breadth and quality of the interphase boundary in non- or compatibilized polymer blends and other inhomogeneous materials. [ABSTRACT FROM AUTHOR]

The structure and property of the films produced from natural rubber latexes such as field latex (FL) and single, double, and triple centrifuged latexes were studied by x-ray diffraction and mechanical testing methods, respectively. Mechanical test shows that tensile strength of the film increases after single centrifugation and then decreases with higher order centrifugation, whereas elongation-at-break (EB) decreases with successive centrifugation. X-ray diffraction study clearly reveals a change of average molecular packing and structural element of the centrifuged films. These results clarify that purification of rubber latex by single centrifugation promotes tensile strength resulting from the elimination of inhibitor type of nonrubbery constituents. Higher order centrifugation causes a decrease of this property because of the elimination of accelerator type nonrubbery elements having the sizes of 1.4–2.5 nm and 18–42 nm. The decrease of EB with sequential centrifugation is associated with the removal of both accelerator and inhibitor type particles. [ABSTRACT FROM AUTHOR]

Considering experimental results obtained on three prototype compounds, TMMC, CsCoCl 3 (or CsCoBr 3 ), and Cu Benzoate, we discuss the importance of non-linear excitations in the physics of quantum (and classical) antiferromagnetic spin chains. soliton dyons spinons breathers [ABSTRACT FROM AUTHOR]

Although testicular teratoma in childhood is regarded as a benign tumor, little is known about the consequences of pediatric teratoma being left untreated. We report herein a case of malignant transformation observed in a mature testicular teratoma that was presumed to have remained benign for >50 years. [ABSTRACT FROM AUTHOR]