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The simultaneous orientation of poly(1,4-butylene)succinate (PBS) and 4,4′-bis(2-benzoxazolyl)stilbene (BBS) or 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene (BBT) in PBS–BBS and PBS–BBT films was investigated during stretching at 80 °C, about 33 °C below the PBS melting temperature. The PBS orientation was first investigated using the 3430 cm −1 infrared band and its order parameter <P...
Macroscopically aligned isotactic polypropylene (iPP) fibers with different diameters ranging from 0.7 to 13.2 μm were successfully fabricated by high-temperature solution electrospinning using an infrared (IR) heating system. Polarized optical microscope (POM), scanning electron microscope (SEM), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and polarized Fourier transform...
Controlling the hierarchical structure of melt-processed polymers is vital to “structuring” processing and tailoring properties of the product. In this work, polypropylene (PP)/octene-ethylene copolymer (POE) blends were injection-molded using so-called dynamic packing injection technique, which imposed oscillatory shear on the gradually cooled melt during the packing solidification stage. In this...
In this study, a novel approach has been developed to introduce orientation to bundle-like β spherulite in iPP samples. The addition of UHMWPE phase, which plays the role of maintaining orientation of iPP chains, into β-nucleation agent nucleated iPP samples leads to the formation of oriented β spherulite in the inner region of injection molded samples. Accordingly, both the tensile strength and impact...
To relate a morphological structure of polymeric specimens to the applied conditions of the production process requires to be able to analyse the morphology and composition of the specimen with high spatial resolution, ideally with a single technique. Infrared microscopy (μFTIR) is a highly attractive technique to map the crystallinity and additive content of polymer samples due to its simplicity...
We investigate the effect of a temperature gradient on the orientation of phase-separated structures in a polyolefin blend system. Phase contrast optical microscopy (PCOM) has been used to measure the morphology of phase separation via spinodal decomposition as a function of phase separation time and temperature gradient. The bicontinuous and interconnected tubelike structure, the characteristic morphology...
Polymorphism and crystal transition are of great significance for property mediation in polymer materials. Isotactic polypropylene (iPP) with β – crystal has been widely utilized for the preparation of high performance plastics or films. In the present work, the structural evolution of initially isotropic β – nucleated iPP (β – iPP) during uniaxial stretching at different temperatures was investigated...
Highly-oriented poly(l-lactic acid) (PLLA) with fibrillar structure and micro-grooves was fabricated through solid hot drawing technology for further improving the mechanical properties and blood biocompatibility of PLLA as blood-contacting medical devices. In order to enhance the melt strength and thus obtain high orientation degree, PLLA was first chain extended with ethylene glycol diglycidyl ether...
Charge carrier transport is one of the most important functions of semiconducting polymers when they are used in organic electronic devices. Due to the transport path limited in two directions, i.e., along the π-conjugated backbone and intermolecular π–π stacking, the backbones are required to be oriented in the desired motifs with respect to the substrate, such as “edge-on” and “face-on” in order...
The superstructures developed in the welds between injection molded plates made from α-nucleated and non-nucleated isotactic polypropylene (iPP) were analyzed by infrared (IR) microscopy, polarized light microscopy (PLM) and differential scanning calorimetry (DSC). Layers of distinct structures and size formed during welding in the welds were identified by PLM. Deformation of spherulites occurred...
Controlling solid-state order of π-conjugated polymers through macromolecular design is essential for achieving high electronic device performance. Our work investigates the various effects of polymer structure on solid-state packing, especially, regarding polymer-packing orientation (edge-on vs. face-on). Various number of thiophene-containing isoindigo polymers (P4TI, P4TI-3, P4TI-4, P6TI-3 and...
As other kinds of polymer materials, amorphous starch obtained by extrusion exhibits shape memory properties when submitted to a specific type of thermomechanical treatment, called Shape Memory Creation Procedure (SMCP). Depending on the draw temperature used in SMCP, X-ray diffraction shows that the amorphous structure of starch is modified, with increasing anisotropy for low temperatures. Concurrently,...
In this work, the different effects of organic montmorillonite (OMMT) particles and shear flow on the crystallization behavior of isotactic polypropylene (iPP) were discussed. While neat iPP and OMMT filled iPP were treated using the multistage stretching extrusion technology, changing the number of laminating-multiplying elements (LMEs) can obtain samples with different dispersion degree of OMMT...
The properties of self-reinforced single polymer composites produced by the Leeds hot compaction process are highly dependent on the compaction temperature as well as the constituent oriented elements used to produce the compacted sheets. In this paper, the variation in tensile mechanical properties of uniaxial hot compacted sheets manufactured from drawn polypropylene (PP) tapes with change in compaction...
The need exists for processing methods that increase the mechanical performance of biodegradable polymers. Recognizing the gap in performance between articles processed using fiber spinning and injection molding, we sought here to develop processing methodology that bridged these two processes while allowing for compositional diversity via blending. Thus, dual electrospinning was utilized to prepare...
The dielectric properties of nanocomposites of polystyrene-b-poly (ethylene-co-butylene)-b-polystyrene (SEBS) triblock copolymers containing organically modified clay nanoparticles featuring controlled spatial orientation at the nanoscale: isotropic, totally oriented and partially oriented, have been investigated and correlated with the nanocomposite morphologies. A slow dielectric relaxation process...
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