A revised morphological model for the crimp structure of tendon is presented. The 300–500 μ diameter tendons mature rat tail are comprised from one to more than ten substructures, called fascicles, 80–320μ diameter. Fascicles each possess a "crimp structure" demonstrable in polarizing microscope and neighboring fascicles within usually exhibit registry.The fascicle itself shown be cylindrical array planar-zig-zag crimped 500–5000Å collagen fibrils. approximate symmetry demonstrated by SEM‡...

The design and fabrication of ultrathin polymer layers are increasing importance because the rapid development nanoscience nanotechnology. Confined, two-dimensional crystallization polymers presents challenges opportunities due to long-chain, covalently bonded nature macromolecule. Using an innovative layer-multiplying coextrusion process obtain assemblies with thousands nanolayers, we discovered a morphology that emerges as confined polyethylene oxide (PEO) made progressively thinner. When...

Abstract Polylactide (PLA)/clay nanocomposites loaded with 3 wt % organomodified montmorillonite and PLA/clay microcomposites containing sodium were prepared by melt blending. We investigated the morphology thermal properties of compared them unfilled PLA, keeping same thermomechanical history. The influence processing temperature on structural characteristics systems was determined. investigations performed differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X‐ray...

Plane strain compression in a channel die is kinematically very similar to drawing; however, the possibility of void formation limited due compressive component stress. In drawing, voids were detected by small-angle X-ray scattering (SAXS) and density measurements poly(methylene oxide) (POM), polypropylene (PP), high-density polyethylene (HDPE), but no voiding was found polyamide 6 (PA 6), low-density polyethylenes (LDPEs), ethylene−octene copolymer (EOC). The slope shape initial elastic...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMorphological alterations during texture-producing plastic plane strain compression of high-density polyethyleneA. Galeski, Z. Bartczak, A. S. Argon, and R. E. CohenCite this: Macromolecules 1992, 25, 21, 5705–5718Publication Date (Print):October 1, 1992Publication History Published online1 May 2002Published inissue 1 October 1992https://doi.org/10.1021/ma00047a023RIGHTS & PERMISSIONSArticle Views1031Altmetric-Citations198LEARN ABOUT THESE...

The process of cavitation during tensile deformation polypropylene was studied. It shown that in injection-molded samples cavities appear the center a sample shortly before yielding. With increasing change their size, number, and orientation from elongated perpendicular to parallel deformation. is visible also as rapid increase volume deformed material. could be suppressed by changing internal morphology fast cooling. prepared compression molding followed quenching, with less perfect...

Abstract Semi‐crystalline polymers can be deformed up to a very high strain. The deformation process involves frequently complete molecular rearrangement of the chain‐folded lamellar morphology into more or less chain‐unfolded fibrillar microstructure. This transformation is likely occur through an intermediate state disorder at local scale. It led formulation concept strain‐induced melting‐recrystallization as main mechanism structure transformation. In contrast, several structural features...

A universal method for determining the modulus of interlamellar amorphous phase semicrystalline polymers was proposed. The basics were presented on example high-density polyethylene (HDPE). local deformation component induced by introduction a swelling agent (hexane). swelling-induced strain and stress estimated based changes long period yield stress, respectively. determined HDPE (≈40 MPa) an order magnitude higher than bulk rubbery (≈3 MPa). other polymers, such as polypropylene (PP),...

The solid state structure and properties of homogeneous copolymers propylene 1-hexene were studied by examining melting behavior, dynamic mechanical response, morphology primarily with atomic force microscopy, wide- (WAXS) small-angle X-ray scattering, tensile deformation. Chain microstructure was analyzed 13C NMR. results indicate that used in this study have an essentially random distribution comonomer. For less than 10 mol% hexane, crystallinity decreases increasing comonomer content, as...

Abstract Polypropylene (PP) thick films were subjected to tensile drawing at various temperatures from the room temperature 100 °C. Morphological alterations during followed by wide‐angle X‐ray scattering, small‐angle and scanning electron microscopy (SEM) of sectioned etched samples, volume strain measurement, light transparency measurement level strain. The morphological observations paralleled with stress–strain determination. Samples drawn 25 40 °C undergo severe cavitation contributing...

The effect of stabilizers, additives, and low molecular weight fractions on cavitation during tensile drawing was studied in polypropylene. additives were extracted from compression molded samples by critical CO2 also a mixture nonsolvents. extract an oily liquid composed antioxidant, processing stabilizer, spectrum Purified polypropylene exhibited surprisingly more intense than pristine as it determined small-angle X-ray scattering volume strain measurements. Intensification the process...

A common belief is that liquids have no strength. An example tap water. However, devoid of dissolved gases and impurities exhibit By analogy, it was expected purification would reduce cavitation increase polymer In contrast to expectation, purified polymers exhibited surprisingly more intense during tensile deformation than pristine ones. It concluded initiated in amorphous phase from homogeneous nuclei are fluctuations free volume. seems introducing a liquid penetrant into interlamellar...

Wide-angle X-ray scattering in conjunction with pole figure technique was used to study the texture of poly(vinylidene fluoride) (PVDF) α and γ phase crystals nanolayered polysulfone/poly(vinylidene films (PSF/PVDF) produced by layer-multiplying coextrusion. In all as-extruded PSF/PVDF films, PVDF nanolayers crystallized into crystals. A large fraction those oriented macromolecular chains perpendicular interface as evidenced from (021) figures. Further refinement occurs during isothermal...