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While blending with flexible polymers has been a commonly employed strategy to enhance the toughness of polylactic acid (PLA), it's still a great challenge to avoid the sacrifice of tensile strength at the same time. In this work, we demonstrate a promising route to simultaneously improve the strength and toughness of PLA by compounding PLA with poly(ε‐caprolactone) (PCL) and PLA grafted multi‐walled carbon nanotubes core‐shell nanofiller (MWNT‐PCLPLA) via a two‐step ring‐opening polymerization and have analyzed the strengthening and toughening mechanism through molecular dynamics simulation. The double polymer layers of MWNT‐PCLPLA effectively improve the interfacial interaction between MWNTs and the matrix, in which the outer PLA layer has the same molecular structure with the matrix and facilitates stress transfer, while the flexible PCL layer can absorb energy through self‐deformation and induce local plastic deformation of the matrix. When the content of MWNTs was only 1 wt%, the strength and elongation at break of PLA/MWNT‐PCLPLA nanocomposites were increased by 47.92% and 690.11% compared to neat PLA. Furthermore, the toughness of nanocomposites reached 11.93 MJ/m3, which is about 16 times that of neat PLA. This novel core‐shell nanofiller with double polymer layers is expected to be further applied in other polymer systems. Highlights: A core‐shell nanofiller with double polymer layers was synthesized.Improved dispersion and interfacial compatibility of nanofillers in matrix.The crystallization ability of PLA was improved by functionalized MWNTs.Simultaneously improved strength and toughness of PLA/MWNT‐PCLPLA nanocomposite. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) was loaded on spherical cellulose‐immobilized tannin resin (CC‐TA) with AgNO3 solution as the silver source, where CC‐TA was prepared by the cross‐linking polymerization of tannin‐based pre‐polymer and cellulose. The tannin introduced onto the cellulose backbone was used as a reduction reagent for silver ions and a stabilizing agent for AgNPs. The AgNPs are uniform, and the average size is about 6.44±3.19 nm. The catalytic activity of AgNPs supported on cellulose‐immobilized tannin resin(CC‐TA@AgNPs)was detected by the reaction of 4‐nitrophenol (4‐NP) to 4‐aminophenol (4‐AP). This reaction could be accomplished within 1.5 min with an apparent rate constant of 2.32 min−1. The CC‐TA@AgNPs has good cycle catalytic performance, and the conversion rate of 4‐NP to 4‐AP in the presence of CC‐TA@AgNPs is about 100 % after five consecutive cycles. Therefore, the CC‐TA@AgNPs is expected to be a promising catalytic material. [ABSTRACT FROM AUTHOR]

The first trans‐selective β‐hydrophosphorylation of ynamides, which provides a facile approach to (Z)‐β‐phosphor‐enamide derivatives in moderate to excellent yields and with excellent regio‐ and stereoselectivity, is described. This transition‐metal‐free reaction is featured with operationally simple procedure, mild reaction conditions, readily available starting materials, broad substrate scope and good functional‐group tolerance. It is noted that the (Z)‐β‐phosphor (V)‐enamides can be prepared from the oxidation of the corresponding phosphine derivatives or the direct β‐hydrophosphorylation of ynamides with diphenylphosphine oxide. In addition, cis‐trans isomerization of (Z)‐β‐phosphor (V)‐enamides can be easily realized to furnish the corresponding (E)‐β‐phosphor (V)‐enamides. This advantageous feature enables the preparation of (Z)‐β‐phosphor (V)‐enamides as well as (E)‐β‐phosphor (V)‐enamides from the same starting materials. [ABSTRACT FROM AUTHOR]

A highly selective synthesis of acyl isoureas and imides from readily accessible amides, isocyanides, alcohols and carboxylates based on reaction solvent selection is described. In the presence of a catalytic amount of [1,1′‐bis(diphenylphosphino)ferrocene]dichloropalladium(II) and cupric acetate, treatment of amides and isocyanides in alcohols at 60 °C provided acyl isoureas in high yields. Interestingly, when other solvents such as acetonitrile was used instead of alcohols, imides were exclusively produced in good to excellent yields via direct N‐acylation of amides with carboxylates as the acyl sources. This protocol offers an attractive alternative approach toward isoureas and imides. [ABSTRACT FROM AUTHOR]

The HMG-CoA reductase ( HMGCR) pathway is an important metabolic route, which is not only present in almost every organism, but also involves virus infection. It has recently been shown that expression levels of IFN-responsive genes were significantly increased in HMGCR-downregulated cells and HMGCR inhibitor-treated cells. The aim of this study was to determine whether inhibition of HMGCR by atovastatin would significantly affect Porcine circovirus type 2 ( PCV2) infection and immunological reaction in BALB/c mice. The results showed atovastatin significantly stimulated PCV2 replication in vivo. Immunological reaction in atovastatin-treated mice was also significantly enhanced during PCV2 infection. Atovastatin also enhanced PCV2-induced illness in mice. The results of this study will provide new insight into the role of atovastatin in PCV2 infection. [ABSTRACT FROM AUTHOR]

The 3-hydroxy-3-methylglutaryl-coenzyme A reductase ( HMGCR) pathway is an important metabolic route that is present in almost every organism. However, whether HMGCR affects the expression of interferon ( IFN)-responsive genes is unclear. In the present study, expression levels of IFN-responsive genes were monitored by real time polymerase chain reaction and enzyme-linked immunosorbent assay. The results showed that expression levels of IFN-responsive genes were significantly increased in HMGCR-downregulated cells and HMGCR inhibitor-treated cells, indicating that inhibition of HMGCR activates the expression of IFN-responsive genes. The result in this study will provide new insight into the role of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in antiviral research. [ABSTRACT FROM AUTHOR]

The isothermal crystallization kinetics of nylon 6/graphene (NG) composites prepared by in situ polymerization was investigated by differential scanning calorimetry. The Avrami equation was used to study the crystallization kinetics. Comparing with nylon 6, it is found that the NG composites (NG-0.1, NG-0.5, and NG-1.0, where the number describes the wt% content of graphene) had higher crystallization rates; the crystallization rate increased remarkably with 0.1 wt% graphene. However, too many crystallization nuclei could not accelerate the crystallization process effectively. The tmax values obtained from the plots of heat flow versus time were in agreement with the tmax values calculated from the half time of crystallization when the graphene content was lower than 1.0 wt%, which means that the values of the Avrami parameters calculated from the half time of crystallization might be in better agreement with the actual crystallization mechanism than that determined from the Avrami plots. The n values of the NG composites ranged between 1.1 and 1.8, which can be interpreted as meaning both one-dimensional and two-dimensional crystallization growth occurred during isothermal crystallization process. The activation energies, which were determined by the Arrhenius' method, varied within the range from −188 to −142 kJ/mol. POLYM. ENG. SCI., 54:2610-2616, 2014. © 2013 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The nonisothermal crystallization kinetics was investigated by differential scanning calorimetry for the nylon 6/graphene composites prepared by in situ polymerization. The Avrami theory modified by Jeziorny, Ozawa equation, and Mo equation was used to describe the nonisothermal crystallization kinetics. The analysis based on the Avrami theory modified by Jeziorny shows that, at lower cooling rates (at 5, 10, and 20 K/min), the nylon 6/graphene composites have lower crystallization rate than pure nylon 6. However, at higher cooling rates (at 40 K/min), the nylon 6/graphene composites have higher crystallization rate than pure nylon 6. The values of Avrami exponent m and the cooling crystallization function F( T) from Ozawa plots indicate that the mode of the nucleation and growth at initial stage of the nonisothermal crystallization may be as follows: two-dimensional (2D), then one-dimensional (1D) for all samples at 5-10 °C/min; three-dimensional (3D) or complicated than 3D, then 2D and 1D at 10-20 and 20-40 °C/min. The good linearity of the Mo plots indicated that the combined approach could successfully describe the crystallization processes of the nylon 6 and nylon 6/graphene composites. The activation energies (Δ E) of the nylon 6/graphene composites, determined by Kissinger method, were lower than those of pure nylon 6. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1381-1388, 2011 [ABSTRACT FROM AUTHOR]

Recently, electroactive biomass‐based hydrogels have attracted great attention for flexible supercapacitor electrodes due to its porous, renewable, earth‐abundant, low‐cost, and environmentally friendly characters. However, it is challenging to facilely prepare biomass‐based hydrogels with simultaneously possesses high mechanical strength and excellent electrochemical performance. In this work, the lignosulfonate/polypyrrole (Lig/PPy) hydrogel (LP54) is obtained. In order to further improve the mechanical strength and electrochemical performance of LP54, functionalized porous carbon nanospheres/lignosulfonate/polypyrrole hydrogel (FPCSLP54) is prepared by introducing a trace of FPCS (≈4.5 wt%) fabricated by hydrothermal treatment the mixture of PCS and pyrrole into the prepared LP54 system. FPCS can be uniformly anchored into Lig/PPy framework. The LP54 and FPCSLP54 exhibit compressive strength of 6.0 and 9.3 kPa with the water content of 94.9% and 94.3%, respectively. Meanwhile, as‐prepared LP54 and FPCSLP54 are separately assembled into symmetric flexible supercapacitors with cellulose/H2SO4 hydrogel electrolytes, which exhibit superior areal capacitance (463 and 522 mF cm−2), good rate capability and outstanding energy density (41.2 and 72.5 µWh cm−2). Remarkably, flexible supercapacitors present outstanding electrochemical stability even suffering 1000 bending cycles. In this work, the strategy to construct electroactive biomass‐based hydrogels is contributed and a new method to enhance the properties of hydrogels is provided. [ABSTRACT FROM AUTHOR]