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Breast cancer is the most prevalent cancer diagnosed in women and the major malignancy that threatens women health, thus we explored the role of long noncoding RNA LINC01605 in triple-negative breast cancer (TNBC). We collected tissue samples from TNBC patients and cultured breast cancer cells to detect LINC01605 levels by RT-PCR. We then constructed LINC01605 knockdown and LINC01605 overexpressed TNBC cell lines, cell proliferation was measured by CCK-8 and colony formation assays, cell migration and invasion were measured by Transwell assay, and aerobic glycolysis of cells was detected. Furthermore, a downstream target gene was found, and its role was confirmed by mouse allogeneic tumor formation. It discovered that LINC01605 expression was significantly increased in TNBC patients, and its high expression predicted a low survival prognosis for TNBC patients. Stable knockdown of LINC01605 remarkably inhibited cell proliferation, migration, and invasion, as well as aerobic glycolysis by inhibiting lactate dehydrogenase A in TNBC cell lines. Notably, knockdown of LINC01605 suppressed in vivo tumor formation and migration in TNBC transplanted mice. In conclusion, targeting long noncoding RNA LINC01605 might serve as a therapeutic candidate strategy to treat patients with TNBC.

Nutrition and lifestyle have a great impact on reproduction and infertility in humans, as they are essential for certain processes such as implantation, placental growth, angiogenesis, and the transfer of nutrients from the mother to the fetus. The aim of this review is to provide the interconnection between nutrition and reproductive health through the insight of omics approaches (including metabolomics and nutrigenomics). The effect of various macronutrients, micronutrients, and some food-associated components on male and female reproduction was discussed. Recent research work was collected through database search from 2010 to 2020 to identify eligible studies. Alterations of metabolic pathways in pregnant women were deliberated with an emphasis on different strategies of lifestyle and dietary interventions. Several nutritional methods, which are important for embryonic and child neurological development, nutritional supplements to lactation, and improved gestational length along with birth weight have been emphasized. Considerable advances in omics strategies show potential technological development for improving human reproductive health.

Widespread distribution of livestock in the natural habitats of large carnivores may negatively impact carnivore populations by reducing wild prey availability and increasing human-carnivore conflicts. In this study, we used camera-trapping data collected in the temperate forests of the Taihang Mountains in North China during 2016-2019 to examine whether and how free-ranging cattle affected habitat use and Diel activity patterns of the endangered North Chinese leopard (Panthera pardus japonensis) and its 2 wild prey species, Siberian roe deer (Capreolus pygargus), and wild boar (Sus scrofa). Residents were also interviewed to record livestock depredation events by leopards during 2015-2019. We found that roe deer spatially avoided sites frequented by cattle, but wild boar did not. In the growing seasons, leopards shared habitats with cattle and tended to increase their diurnal activities where cattle were present. All 3 study species exhibited fine-scale spatial-temporal segregation to cattle. Leopards selectively preyed on calves over adult cattle and livestock depredation frequency was positively correlated with the detection rates of cattle and wild prey, but not that of leopard. These findings not only show that through behavioral adaption large carnivores and their ungulate prey may persist under livestock disturbance, but also highlight how important proper livestock management is for conserving North Chinese leopards in this region. To enhance livestock management and mitigate human-leopard conflicts, we recommend specific actions, such as better guarding of free-ranging cattle or adoption of a captive farming system.

Efficient removal of per- and polyfluoroalkyl substances (PFAS) from contaminated waters is urgently needed to safeguard public and environmental health. In this work, novel magnetic fluorinated polymer sorbents were designed to allow efficient capture of PFAS and fast magnetic recovery of the sorbed material. The new sorbent has superior PFAS removal efficiency compared with the commercially available activated carbon and ion-exchange resins. The removal of the ammonium salt of hexafluoropropylene oxide dimer acid (GenX) reaches99 % within 30 s, and the estimated sorption capacity was 219 mg g

White matter hyperintensities (WMH) are common in elderly individuals and cause brain network deficits. However, it is still unclear how the global brain network is affected by the focal WMH. We aimed to investigate the diffusion of WMH‐related deficits along the connecting white matters (WM). Brain magnetic resonance imaging data and neuropsychological evaluations of 174 participants (aged 74 ± 5 years) were collected and analyzed. For each participant, WMH lesions were segmented using a deep learning method, and 18 major WM tracts were reconstructed using automated quantitative tractography. The diffusion characteristics of distal WM tracts (with the WMH penumbra excluded) were calculated. Multivariable linear regression analysis was performed. We found that a high burden of tract‐specific WMH was related to worse diffusion characteristics of distal WM tracts in a wide range of WM tracts, including the forceps major (FMA), forceps minor (FMI), anterior thalamic radiation (ATR), cingulum cingulate gyrus (CCG), corticospinal tract (CST), inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus‐parietal (SLFP), superior longitudinal fasciculus‐temporal (SLFT), and uncinate fasciculus (UNC). Furthermore, a higher mean diffusivity (MD) of distal tracts was linked to worse attention and executive function in the FMI, right CCG, left ILF, SLFP, SLFT, and UNC. The effect of WMH on the microstructural integrity of WM tracts may propagate along tracts to distal regions beyond the penumbra and might eventually affect attention and executive function., A high burden of tract‐specific WMH was related to an increased MD of distal WM tracts. A higher MD of distal tracts was linked to worse attention and executive function. The microstructural changes caused by WMH may propagate along tracts to distal regions beyond the penumbra.

Myocardial infarction (MI) leads to cardiac remodelling and heart failure. Cardiomyocyte apoptosis is considered a critical pathological phenomenon accompanying MI, but the pathogenesis mechanism remains to be explored. MicroRNAs (miRs), with the identity of negative regulator of gene expression, exist as an important contributor to apoptosis. During the experiment of this study, MI mice models were successfully established and sequencing data showed that the expression of miR-23a-5p was significantly enhanced during MI progression. Further steps were taken and it showed that apoptosis of cardiac cells weakened as miR-23a-5p was downregulated and on the contrary that apoptosis strengthened with the overexpression of miR-23a-5p. To explore its working mechanisms, bioinformatics analysis was conducted by referring to multi-databases to predict the targets of miR-23a-5p. Further analysis suggested that those downstream genes enriched in several pathways, especially in the PI3K/Akt singling pathway. Furthermore, it demonstrated that miR-23a-5p was negatively related to the phosphorylation of PI3K/Akt, which plays a critical role in triggering cell apoptosis during MI. Recilisib-activated PI3K/Akt singling pathway could restrain apoptosis from inducing miR-23a-5p overexpression, and Miltefosine-blocked PI3K/Akt singling pathway could restrict apoptosis from inhibiting miR-23a-5p reduction. In conclusion, these findings revealed the pivotal role of miR-23a-5p-PI3K/Akt axis in regulating apoptosis during MI, introducing this novel axis as a potential indicator to detect ischemic heart disease and it could be used for therapeutic intervention.

An outbreak of coronavirus disease 2019 (COVID‐19) pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), started in Wuhan City, Hubei Province, China. The real‐time reverse‐ transcriptase polymerase ‐ chain ‐ reaction (RT ‐ PCR) method can be used for the detection of SARS‐CoV‐2 in oral swabs1. Now, results have confirmed the presence of the live virus in stool samples from patients with COVID‐ 192.This article is protected by copyright. All rights reserved.

Duchenne muscular dystrophy (DMD) is a lethal genetic muscle disorder caused by recessive mutations in dystrophin gene, affecting 1/3000 males. Gene therapy has been proven to ameliorate dystrophic pathology. To investigate therapeutic benefits from long-term effect of human mini-dystrophin and functional outcomes, transgenic mdx mice (Tg-mdx) containing a single copy of human mini-dystrophin (∆hDys3849) gene, five rods (Rods1-2, Rods22-24), and two hinges (H1 and H4) driven by a truncated creatine-kinase promoter (dMCK) in a recombinant adeno-associated viral vector (rAAV) backbone, were generated and used to determine gene expression and improvement of muscle function. Human mini-dystrophin gene expression was found in a majority of the skeletal muscles, but no expression in cardiac muscle. Dystrophin-associated glycoproteins (DAGs) such as sarcoglycans and nNOS were restored at the sarcolemma and coincided with human mini-dystrophin gene expression at the ages of 6, 10, and 20 months; Morphology of dystrophic muscle expressing the human mini-dystrophin gene was improved and central nuclei were reduced. Myofiber membrane integrity was improved by Evans blue dye test. Improvement in treadmill running and grip force was observed in transgenic mice at 6 months. Tetanic force and specific force of tibialis anterior (TA) muscle were significantly increased at the ages of 6, 10, and 20 months. Pseudohypertrophy was not found in TA muscle at 10 and 20 months when compared with wild-type C57 (WT) group. This study demonstrated that the long-term effects of human mini-dystrophin effectively ameliorated pathology and improved the functions of the dystrophic muscles in the transgenic DMD mouse model.

Cardiac remodeling is a common pathophysiological change associated with acute myocardial infarction (AMI). Recent evidence indicates that microRNAs are strong posttranscriptional regulators which play an important role in regulating the microenvironment of myocardial tissue after AMI. In this study, we sought to explore the potential role and underlying mechanism of miR-130 in AMI. H9c2 cells were cultured under hypoxic conditions to simulate myocardial infarction. The influence of aberrantly expressed miR-130 on H9c2 cells under hypoxia was also estimated with RT-PCR, western blot and enzyme-linked immunosorbent assay. Using bioinformatics methods, of miR-130 target genes were verified with luciferase reporter assay. Then, the effects of miR-130 on AMI were identified in an induced myocardial injury model in rats. The results show that miR-130 downregulation remarkably decreased hypoxia-induced inflammation and fibrosis related protein expression in H9c2 cells and reversed hypoxia-induced peroxisome proliferator-activated receptor γ (PPAR-γ) inhibition. A bifluorescein reporter assay further confirmed that PPAR-γ was a target gene of miR-130. This study verified that PPAR-γ has a cardioprotective effect by inhibiting NFκB-mediated inflammation and TGF-β1-mediated fibrosis. In vivo experiments confirmed that downregulation of miR-130 expression promotes PPAR-γ-mediated cardioprotective effects by suppressing inflammation and myocardial fibrosis. Taken together, these findings suggest that miR-130 knockdown alleviates infarction-induced myocardial injury by promoting PPAR-γ expression.

Given the advantages of the latex compounding method, clay was nanodispersed into a styrene butadiene rubber (SBR) matrix, and butadiene–styrene–vinyl pyridine rubber (VPR) latex was introduced to in situ-modified clay to support strong interfacial interaction between clay layers and SBR matrix. The strong interfacial interaction was investigated through Fourier-transform infrared spectra, X-ray photoelectron spectroscopy, and dynamic mechanical properties. The structure and properties of SBR/VPR/clay nanocomposites were studied through X-ray diffraction, high-resolution transmission electron microscope, and mechanical and abrasion testing. The aspect ratio of clay layers was calculated using Halpin–Tsai model. The largely improved mechanical properties and abrasion resistance was adequate evidence that the exfoliated structures with large aspect ratios and strong interfacial interaction play critical roles in nano-reinforcement. POLYM. COMPOS., 2017. © 2017 Society of Plastics Engineers

Here, a simplified synthesis of graphitic carbon nitride quantum dots (g-C3 N4 -QDs) with improved solution and electroluminescent properties using a one-pot methylamine intercalation-stripping method (OMIM) to hydrothermally exfoliate QDs from bulk graphitic carbon nitride (g-C3 N4 ) is presented. The quantum dots synthesized by this method retain the blue photoluminescence with extremely high fluorescent quantum yield (47.0%). As compared to previously reported quantum dots, the g-C3 N4 -QDs synthesized herein have lower polydispersity and improved solution stability due to high absolute zeta-potential (-41.23 mV), which combine to create a much more tractable material for solution processed thin film fabrication. Spin coating of these QDs yields uniform films with full coverage and low surface roughness ideal for quantum dot light-emitting diode (QLED) fabrication. When incorporated into a functional QLED with OMIM g-C3 N4 -QDs as the emitting layer, the LED demonstrates ≈60× higher luminance (605 vs 11 Cd m-2 ) at lower operating voltage (9 vs 21 V), as compared to the previously reported first generation g-C3 N4 QLEDs, though further work is needed to improve device stability.

A highly dispersed montmorillonite (MMT)/styrene-butadiene rubber (SBR) nanocomposite is prepared by combining the latex compounding method and spray-drying process. The MMT layers exhibit a nearly exfoliated structure in the spray-dried powder. But when subjected to strains higher than 40%, the sprayed powdered nanocomposite goes through an irreversible transformation of the MMT network, showing a dramatic decrease in the storage modulus. XRD, SEM, and high resolution transmission electron microscopy results confirm the structure transformation of the MMT/SBR nanocomposite during processing. With intensive shearing during milling, the MMT layers are oriented, and further aggregations are observed in the vulcanizate. The processing procedures greatly alter the structures of the MMT/SBR nanocomposite. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Due to the lack of tumor-specific anticancer agents, the discovery and development of new types of highly selective anticancer agents is still a very urgent topic. Herein, we present our contribution to concise construction of novel chiral spirooxindole-type pyranopyrimidines exhibiting a unique profile of biological activities. We have found that this new type of spiro alkaloid could inhibit the proliferation of various cancer cells in a preliminary biological evaluation. These findings suggested that spirooxindole-type pyranopyrimidines, developed by an asymmetric Michael/cyclization strategy, can potentially serve as a new kind of anticancer candidate.

The high cost of halogenated butyl rubber, traditional inner liner compound, has been an obstacle for the further development of tire industry. SBR/rectorite nanocompound was developed to reduce the cost, but it has relatively poor processability because of strong filler network interaction. In this work, SBR/rectorite nanocompound filled with 60 phr rectorite was prepared by latex compounding method, and glycerin was introduced to reduce the filler network interaction, besides, aromatic oil was added to further improve the processability. The addition of glycerin or aromatic oil could not change the microstructure of the nanocomposite. FTIR spectra indicated the hydrogen bond interaction between glycerin and rectorite layers. RPA analysis showed that the filler network interaction was reduced by adding glycerin or aromatic oil. With the addition of glycerin, the mechanical property of the nanocomposites was improved, along with the disappearance of delayed vulcanization, and the high gasbarrier property was maintained. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

In practice, rubber articles often fail attributed to crack growth under static and dynamic conditions. In this work we designed various experimental methods with precut samples to characterize the effect of nanodispersed clay on the crack growth resistance. The results indicate that the incorporation of nanodispersed clay can greatly improve the crack growth resistance of natural rubber (NR)/carbon black (CB), as evidenced by the enhancement of the tensile strength under static conditions, and improvement of flex-fatigue properties under dynamic conditions, which could find wide application in the industry. Furthermore, the scanning electron microscopy (SEM) observations and molecular simulations are combined to uncover the underlying mechanism of the crack growth resistance, highlighting the enhanced polymer orientation and highly stretched ligaments, and the orientation of the clay sheets. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers

Drug lead synthesis by the rapid construction of chiral molecular complexity around the biologically relevant framework using a highly efficient strategy is a key goal of organic synthesis. Herein, a highly efficient and convenient strategy that allows the rapid synthesis of highly optically active methylthioimidazolines through the novel rosin-derived thiourea-catalyzed asymmetric synthesis of cyclic thioureas with high levels of enantio- and diastereoselectivity (up to 99% ee, and 20:1 dr) via Mannich reaction is described fior the first time. Several of the new methylthioimidazolines showed extremely promising antipyretic activity in the development of neuroinflammation through preliminary biological studies. Additionally, to gain a better understanding of the structural stability-activity relationships, explicit molecular dynamics (MD) simulations in water at room temperature and at body temperature were investigated.

Accidental ingestion or injection of household products sometimes occurs due to their accessibility, but the toxic manifestations have not been well characterized when they are internally administered. The aim of this study was to investigate the toxic effects induced by ingestion or injection of different ionic surfactants and disinfectants in rats. The test drugs involved benzalkonium and benzethonium (BZK and BZT, both cationic surfactants used as disinfectants), alkyldiaminoethylglycine (AEG, an amphoteric surfactant used as a disinfectant), linear alkylbenzenesulfonate (LAS, an anionic surfactant), polyoxyethylene cetylether (PEC, a nonionic surfactant), chlorhexidine (CHX, not a surfactant but a disinfectant) and saline (control). Male Sprague–Dawley rats were administered one of the test drugs orally (p.o.), intravenously (i.v.) or intraarterially (i.a.). The fatal effects appeared rapidly ( 5 h) in i.a./p.o.-administered rats after a dose of around LD50, although the progress and degree of toxic effects varied among the drugs tested. In intravascular administration, BZK and BZT were fatal at doses of 15–20 mg kg−1. Higher concentrations in lung and kidney than in blood were determined. CHX showed a high toxic effect compared with cationic surfactants. The rats administered anionic (LAS) or amphoteric (AEG) surfactant died in less than 24 h at doses over 100 mg kg−1. In p.o. administration, the toxic effects were concentration/dose-dependent, and all rats administered high doses of surfactants except for PEC died at 5–20 h. The overall toxic ranks could be: cationic surfactant/CHX> anionic/amphoteric surfactant > nonionic surfactant. Copyright © 2011 John Wiley & Sons, Ltd.

Dopamine (DA) polymerization has received significant attention in many fields, however, almost all of the works are limited to aqueous solution and hamper its wide application. This paper reports that amines can trigger DA polymerization by capturing the H+ from DA hydrochloride and intermediates to accelerate the generation of radical species in water or organic solvents. Increasing concentration and decreasing pKb of amines cause the reaction equilibrium to shift toward the product polydopamine (PDA). Water-soluble and easily-removable Na2 SO4 nanowires and NaCl cubes can be used as templates to prepare different morphologies of hollow PDA structures by DA polymerization in ethanol solution. The carbonization production of PDA nanotubes at 900 °C (PDNC-900) is obtained and demonstrates electrochemical activity in the oxygen reduction reaction that is comparable to that of Pt/C.

Poly(lactic acid) (PLA)-block-poly(norbornene) (PNB) copolymers which bear photocrosslinkable cinnamate side-chains are synthesized by combining the ring-opening metathesis polymerization (ROMP) of norbornenes with the ring-opening polymerization (ROP) of lactides. Highly porous 3D scaffolds with tunable pore sizes ranging from 20 to 300 µm are fabricated through liquid–solid phase separation. Scaffolds with an average pore size around 250 µm, which are under investigation as bone grafting materials, are reproducibly obtained from freeze-drying 5% w/v benzene solutions of PLA-b-PNB copolymers at −10 °C. As a demonstration of the impact of photocrosslinking of cinnamate side-chains, scaffolds are exposed to UV radiation for 8 h, resulting in a 33% increase in the compressive modulus of the polymeric scaffold. The foams and the methodology described herein represent a new strategy toward polymeric scaffolds with potential for use in regenerative medicine applications.

The effect of dispersion of clay in rubber on the mechanical properties and flame retardance of rubber/montmorillonite (MMT) nanocomposites and rubber/MMT microcomposites were investigated in the present article, and the results were compared with the performance of silica reinforced rubber composites. Cone calorimeter test and limiting oxygen index test were employed to evaluate the flame retardance. From the results, it could be seen that the rubber/MMT nanocomposites always possessed the best flame retardance, such as lower peak heat release rate and higher fire performance index value. In addition, the rubber/MMT nanocomposites also showed better mechanical properties than the pure rubber and the other composites, especially in tear strength. With the rubber/silica composites, as expected, the silica could appropriately endow the rubber with flame retardance. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Based on the fact that rubber can be chemically modified by sulfur, and sulfur can diffuse into rubber driven by a concentration gradient and chemical reaction, a new approach for the preparation of a polymer with a gradient from rubbery to glassy phase has been developed using the sulfur-vulcanization reaction of rubber. The gradient polymer obtained exhibits a wide transition range spanning over 100°C with a peak half-width of 69 °C. The mechanism of forming the gradient structure is also discussed.

The styrene butadiene rubber (SBR)–clay nanocompounds were prepared by the latex compounding method, and then hexadecyl trimethyl ammonium bromide (C16) and 3-aminopropyl triethoxy silane (KH550) were added into these nanocompounds on a two-roll mill to prepare nanocomposites with strong interfacial interaction. The structure and properties of SBR–clay nanocomposites were carefully studied by X-ray diffraction (XRD) studies, transmission electron microscopy (TEM), Rubber Process Analyzer (RPA), and mechanical testing. Compared with unmodified nanocomposites, the dispersion structure of modified SBR–clay nanocomposites is better with part rubber-intercalated or part modifier-intercalated structure. The tensile strength and the modulus at 300% elongation of modified SBR–clay nanocomposites are higher than three times of those of unmodified nanocomposites, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1826–1833, 2007

Natural rubber (NR)–clay (clay is montmorillonite) and chloroprene rubber (CR)–clay nanocomposites were prepared by co-coagulating the rubber latex and clay aqueous suspension. Transmission electron microscopy showed that the layers of clay were dispersed in the NR matrix at a nano level, and the aspect ratio (width/thickness) of the platelet inclusions was reduced and clay layers aligned more orderly during the compounding operation on an open mill. However, X-ray diffraction indicated that there were some nonexfoliated clay layers in the NR matrix. Stress–strain curves showed that the moduli of NR were significantly improved with the increase of the amount of clay. At the same time, the clay layers inhibited the crystallization of NR on stretch, especially clay content of more than 10 phr. Compared with the carbon-black-filled NR composites, NR–clay nanocomposites exhibited high hardness, high modulus, high tear strength, and excellent antiaging and gas barrier properties. Similar to NR–clay nanocomposites, CR–clay nanocomposites also exhibited high hardness, high modulus, and high tear strength. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 318–323, 2005

Rectorite/styrene–butadiene copolymer (SBR) nanocomposite was prepared by cocoagulating SBR latex and rectorite/water suspension. Transmission electron microscopy showed that the layers of rectorite were well dispersed in the SBR matrix and the aspect ratio (width/thickness) of it was higher than that of montmorillonite (MMT). X-ray diffraction indicated that the nanocomposite produced by this method was of neither intercalated type nor exfoliated type. The gas barrier properties and mechanical properties of the novel nanocomposites were excellent. The nanocomposites are expected to be candidates for tire tube or inner materials. Rectorite appears to be a promising filler for the nanocomposite. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 324–328, 2005

Four organoclay (OC)/ethylene–propylene–diene rubber (EPDM) nanocomposites with different ethylene contents were prepared by melt blending. X-ray diffraction spectrum (XRD) and transmission electronic microscope (TEM) photos showed that OC/EPDM nanocomposites were intercalated, and the ethylene content had little influence on the dispersion of OC. The addition of OC prolonged the optimum cure time and reduced the crosslink density of OC/EPDM. The improvement in tensile strength of OC/EPDM nanocomposites with high ethylene contents (67–70%) was larger than that of OC/EPDM nanocomposites with low ethylene contents (52–52.5%). XRD results of the stretched samples testified that the extension promoted orientation of silicate layers, and induced crystallization of polyethylene (PE) segments in OC/EPDM nanocomposites with high ethylene contents. The highly oriented micro-fibrillar structure and more oriented amorphous chains, which resulted from strain-induced crystallization of PE segments and the orientation of clay layers in OC/EPDM nanocomposites with high ethylene contents (67–70%), should be responsible for larger improvement in tensile strength than that of those nanocomposites with low ethylene contents (52–52.5%) © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 914–919, 2006

The flammability of montmorillonite (MMT)/SBR nanocomposites, prepared by the technique of cocoagulating rubber latex and clay aqueous suspension, was investigated. Flammability studies, performed on the cone calorimeter, showed that the maximum heat release rate (HRR) of SBR decreased from 1987 to 1442 kw/m2 with the introduction of nanoclay (20 phr). This nanocomposite had the lowest mass loss rate and the largest amount of char upon combustion compared with conventional SBR composites with the same clay loading and pure SBR. The permeability properties of MMT/SBR composites were also measured. It was deduced that the lowered permeability was responsible for the reduced mass loss rate and hence the lower HRR. Unfortunately, the oxygen index (OI) of the nanocomposites was not as high as expected. Combination of Mg(OH)2 and clay was effective for the improvement of both mechanical properties and OI. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 844–849, 2005

The size and comcentration of free-volume holes of two kinds of montmorillonite (MMT)/styrene-butadiene rubber (SBR) nanocomposites were investigated by positron annihilation lifetime spectroscopy (PALS). Strong interfacial interaction caused an apparent reduction of the free-volume fraction of rubber probaly by depressing the formation of free-volume holes in the interfacial region. Interfacial interaction in MMT/SBR nanocomposites was weaker than that in SBR filled with carbon black.

Summary: Three rubber-based nanocomposites, natural rubber (NR), styrene-butadiene rubber (SBR), and ethylene-propylene-diene rubber (EPDM) matrixes, were prepared with octadecylamine modified fluorohectorite (OC) by melt blending. X-ray diffraction (XRD) revealed that the SBR/OC and EPDM/OC nanocomposites exhibited a well-ordered intercalated structure and a disordered intercalated structure, respectively. In the case of the NR/OC nanocomposite, it exhibited an intermediate intercalated and even exfoliated structure. These results were in good agreement with transmission electron microscopy (TEM) observations. Furthermore, in the NR/OC and SBR/OC systems, the mixing process played a predominant role in the formation of nanometer-scale dispersion structure, whereas the intercalated structure of EPDM/OC formed mainly during the vulcanization process. The tensile strength of SBR/OC and EPDM/OC nanocomposites loading 10 phr OC was 4–5 times higher than the value obtained for the corresponding pure rubber vulcanizate, which could be ascribed to the slippage of the rubber molecules and the orientation of the intercalated OC. For the strain-induced crystallization NR, the exfoliated OC efficiently improved the modulus of the NR/OC nanocomposite relative to the pure NR. However, its hindrance on NR crystallization during the tensile process may be the main reason for the decrease in tensile strength of NR/OC. XRD diffraction patterns of three nanocomposites containing 10 phr organoclay.

Summary: Several rubber/starch composites in which the starch particles are in an amorphous state and are smaller than 1 μm, prepared by directly mixing and co-coagulating rubber latex and starch paste, exhibit higher hardness, stress at 100%, tensile strength, and tear strength relative to the corresponding rubber/starch composites prepared by direct blending. TEM micrograph of starch/SBR composite.