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The pristine and acetylated cellulose nanocrystal (CNC) particles were incorporated with poly(ε-caprolactone) to prepare two kinds of green nanocomposite systems: the former is incompatible, while the latter compatible thermodynamically. A rheological study was then performed systematically with various flow fields, including linear and nonlinear dynamic shear flow, creep and start-up flow. Some interesting...
Polymeric materials with alternating multi-layer structure have gained much attention in the field of biomimic, where many methods were used to prepare materials with such structure for various functionalities. A simple method based on high speed thin-wall injection molding (HSTWIM) has been proposed in our previous studies for the easy fabrication of multi-layer functional polymeric materials. Herein,...
Research interest in electrochemical redox stimulus has grown considerably due to its easy trigger mode, in which the linkers have played important roles, such as the β-cyclodextrin-ferrocene (β-CD-Fc) linker. Star amphiphilic copolymers with well-defined and flexible structures are considered to be excellent choices for drug delivery systems (DDSs). Driven by the idea that using star polymers to...
For the toughening of thermoplastics by using elastomeric components, the relatively high contents of elastomeric phase are commonly demanded to trigger the brittle-to-ductile transition. However, an obvious drawback of remarkably decreased strength and rigidity may arise after incorporation of large amount of elastomeric species. The main thinking in our present work is to achieve a good toughness-strength...
The key for fiber reinforced polymer composites is the interfacial interaction between fiber and polymer matrix. The crystallization of polymer on the surface of fiber as a possible way to enhance the interfacial interaction has received increasingly attention. In this work, the transcrystalline (TC) formation and properties of isotactic polypropylene (iPP) on ramie fiber surface, as induced either...
Obtaining network-like morphology (rubber particles are unevenly distributed in the matrix, forming a discontinuous rubber network structure) has been considered to be an effective strategy to optimize the toughness of rubber-toughened polymers. However, it is very difficult to achieve using conventional processing method. In this work, taking elastomer-toughened polylactide (PLA) as an example, we...
To prepare composites with anisotropic conductive networks, electrical conductive polymer composites (CPCs) consisting of polypropylene (PP) and carbon nanotubes (CNTs) filled polyethylene (PE) are fabricated through high speed thin-wall injection molding. Morphological study demonstrates that CNTs are localized in PE phase while the alternating multilayer structure with different polymer phases elongated...
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...
Polypropylene random copolymer (PPR) is one of important polypropylene types for the application fields needing for excellent toughness. Because of the random copolymer chain configuration, the polymorphic behavior of PPR is difficult to be altered even by adding β-nucleating agent (β-NA). In this study, a promising method was developed by adding isotactic polypropylene (iPP) into PPR/β-NA blend,...
In this study, electrospun immiscible blend fibers of poly(vinylidene fluoride) (PVDF)/polysulfone (PSF) were prepared. Due to the strong shearing during electrospinning, cocontinuous fibers of PVDF in the PSF matrix were obtained despite the minor composition of PVDF (5–30 wt.%) in the blend. After annealing these electrospun blend fibers above the melting temperature of PVDF (170 °C) and the glass...
Crystalline structures especially the interfacial crystalline layers of semi-crystalline polymer/filler composites are markedly affected by the extensional force and keep an important role in macroscopic properties. In this study, we prepared the polypropylene and SiO 2 –MgO–CaO whisker (SMCW) composite fibers by melt-spun technology. The structure–property relationship of the PP/SMCW composite...
In this study, the effects of α- and β-nucleating agents (α-NA and β-NA) on the toughening behavior of impact polypropylene copolymer were ascertained with respect to three test temperatures (23, 0 and −15 °C). The addition of α-NA impacted the toughness slightly for all test temperatures. However, the tendency of impact strength vs. β-NA content at 0 °C significantly differs from that of the other...
By utilizing electrospun blend fibers of polystyrene (PS) and poly(ethylene oxide) (PEO) with diameters in sub-microns, nanodroplets of the minor component (PEO) were obtained by annealing the blend fibers above the glass transition temperature (T g ) of the matrix polymer (PS), as a result of the Rayleigh-Plateau instability in the melt. However, direct thermal annealing of the PS/PEO blend...
The polar crystalline phase is the most important crystal mode for poly(vinylidene fluoride) (PVDF); its high content is urgently desired in the large-scale processing fabrication likes injection-molding. In this study, we proposed a convenient pathway to achieve large amount of polar phase in injection-molding part through cooperation of exerting oscillatory shear field and adding nanoclay. The effects...
In this work, we investigated the epitaxial crystallization and its determinant factor in the blends of high density polyethylene (HDPE) and a low crystallizable propylene-ethylene random copolymer (PPR) during injection molding. For PPR dominated blend (blended with 30 wt.% HDPE), epitaxial growth of HDPE on the PPR crystals can be achieved, as demonstrated by two-dimensional wide-angle X-ray diffraction...
Effects of electric poling, mechanical stretching, and dipolar interaction on the formation of ferroelectric (β and/or γ) phases in poly(vinylidene fluoride) (PVDF) have been studied in electrospun fibers of PVDF/polyacrylonitrile (PAN) and PVDF/polysulfone (PSF) blends with PVDF as the minor component, using wide-angle X-ray diffraction and Fourier transform infrared techniques. Experimental results...
Large amount of work has been reported on the annealing of polypropylene (PP) and the related changes in mechanical properties. However, the structure–property correlations and the physical origin of annealing induced microstructural evolution are still not very clear. In this work, taking β-form PP (β-PP) as example, the microstructural changes induced by annealing were investigated from macromolecular...
Injection-molded products usually show hierarchical structure from skin to core due to the existence of shear gradient and temperature gradient. Investigating the hierarchical structure is helpful to better understand the structure-property relationship of injection-molded sample, which is important for design and preparation of polymer products with high performance. In this work, the hierarchical...
In this work, recycled Poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) plastic (PETG) was used to enhance the properties and lower the cost of polypropylene(PP). In order to adjust the interfacial adhesion, three triblock copolymers having the same styrene block at two ends but different block in the middle, were used a the compatibilizers, namely, styrene–ethylene/butylene–styrene...
The polymer matrix structure and the interface are strongly influenced by filler in semi-crystalline polymer composites because the fillers have the potential to nucleate the polymer crystallization. The structure of the nucleated crystalline polymer on filler is of particular interest and is a key to the interfacial enhancement. In this work, whiskers, with a large length/diameter ratio and with...
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