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White circularly polarized organic light‐emitting diodes (CP‐WOLEDs) are central to prospective 3D displays and lighting sources. However, owing to the unwanted charge trapping effect and inefficient chirality transfer, the development of CP‐WOLEDs with a high color rendering index (CRI) and large dissymmetry factor (gEL) is challenging. Herein, a pioneering strategy of chiral co‐assembly‐sensitized circularly polarized luminescence (CCS‐CPL) is proposed for improving the performance of white circularly polarized electroluminescence (CP‐EL). Chiral co‐assembled sensitizers ((S‐/R‐Cz)0.2‐(I‐P)0.8) are smartly developed using π–π stacking interactions between the chiral binaphthyl derivatives (S‐/R‐Cz) and achiral conjugated pyrene‐based polymer (I‐P) in a molar ratio of 1:4. Using the chiral co‐assembly‐sensitized strategy on achiral aggregation‐induced emission (AIE) dyes for emitting layers (EMLs) of OLEDs, full‐color achiral AIE‐active dyes can be sensitized by chiral co‐assembly (S‐/R‐Cz)0.2‐(I‐P)0.8. The color‐tunable white CP‐EL performance can be achieved at the CIE coordinates of (0.33, 0.33) with an ultrahigh CRI of 93 and a large gEL value up to 0.071. This study thus provides a valuable guidance for CCS‐type CP‐WOLEDs. [ABSTRACT FROM AUTHOR]

The properties of modified polypropylene (PP) materials are closely related to their phase structure. In this work, polyolefin elastomer (POE)‐toughened PP materials with different phase structures were designed by using various types of POEs (ethylene‐butene 710, 110, ethylene‐propylene 6202, ethylene‐octene 8200). Then, the effects of phase separation in PP/POE blends on both thermal and tensile properties as well as ultraviolet (UV) resistance were investigated. The results revealed that the POE type hardly affected the melt flow rate, melting or crystallization behavior of the modified PP samples. Moreover, scanning electron microscopy results showed that POE6202 had a smaller dispersed phase size in PP (0.1–0.5 μm), which improved the low‐temperature elongation at break. PP/POE110 blends with a larger microdomain (1–5 μm) had better high‐temperature tensile strength. Further, when toughened with POE110 and POE6202 simultaneously, modified PP had excellent low‐temperature elongation (272%@ −40°C) without sacrificing as much of its high‐temperature tensile strength (10.4 MPa@70°C). Finally, Electron Paramagnetic Resonance tests showed that the addition of amorphous POE decreased the intensity of free radicals generated in PP during irradiation and promoted their attenuation during decay. This indicated that the introduction of POE improved the UV resistance of PP. [ABSTRACT FROM AUTHOR]

White circularly polarized organic light‐emitting diodes (CP‐WOLEDs) are of great significance in potential lighting sources and full‐color 3D displays. However, High‐performance white CP‐EL sources are almost unexplored. We have constructed full‐color CP‐EL devices based on chiral co‐assemblies by using three achiral conjugated pyrene‐based dyes (BP, w‐WP and c‐WP) doped with chiral binaphthyl‐based enantiomers (S‐/R‐M) as the EMLs through an intermolecular chirality induction mechanism. (S‐/R‐M)0.2‐(c‐WP)0.8 films exhibit regular helix nanofibers under annealing treatment and emit strong white CPL. Significantly, remarkable CP‐WOLEDs based on (S‐/R‐M)0.2‐(c‐WP)0.8 were achieved with |gEL| values as high as 6.2×10−2 and an excellent CRI of 98 at the CIE coordinates of (0.33, 0.33). These are the highest gEL and CRI values of reported CP‐WOLEDs to date. This is the first achievement of CP‐WOLEDs based on chiral co‐assembled helix nanofiber emitters, and provides a valuable strategy with which to develop white CP‐EL for future practical applications. [ABSTRACT FROM AUTHOR]

The application of polypropylene (PP) is greatly restricted by its poor low‐temperature tensile properties. In this work, a polypropylene random copolymer (rPP) and polypropylene/ethylene‐propylene‐diene monomer graft copolymer (gPP) were used to improve the toughening effect of polyolefin elastomer (POE) on PP. The influences of this addition on the phase morphology, crystallization, and rheological and mechanical properties were investigated. The results revealed that rPP both reduced the size of PP spherulites and improved the interfacial cohesion of the PP/POE blend, which endowed the material with greater tensile properties and melt flow rate. The elongation at break of PP/POE/rPP at 23, 0, −20, and −40°C was 400%, 221%, 205%, and 106%, respectively. These represented increases of more than 200% compared with those of PP/POE. The tensile strengths of PP/POE/rPP were 15.0, 19.1, 21.5, and 27.4 MPa at 23, 0, −20, and −40°C, respectively, which were comparable to those of PP/POE. Finally, the effects of the injection molding process parameters on the mechanical properties and phase morphology of rPP‐modified PP/POE blends were studied. [ABSTRACT FROM AUTHOR]