Miscibility enhancement on the poly(vinylchloride)/poly(methylmethacrylate) blend and characterization by inverse gas chromatography: The corrected polymer–polymer interaction parameters from the probes dependency

The miscibility of poly(vinyl chloride)/poly(methylmethacrylate) (PVC/PMMA) system was improved by introducing some pyrrolidone units into the main chains of PMMA. For that purpose, we have synthesized two copolymers of poly(methylmethacrylate‐co‐vinylpyrrolidone) (MMVP) through a radical polymerization and carried out a comparative study of PVC/MMVP blends by inverse gas chromatography (IGC) and differential scanning calorimetry (DSC) methods. The adequacy of seven n‐alkane probes has been tested to determine the thermodynamic parameters. The miscibility of the two systems has been proved by a single T_g for each blend. This observation was also confirmed by DSC analysis. To highlight the presence of interaction and its intensity between PVC and MMVP in the blends, the polymer–polymer interaction parameters have been evaluated by IGC trough which the influence of the solute has been resolved. The Schneider approach confirmed the miscibility of these systems as the K deviates positively from unity. The miscibility has been appeared highlighted from the positive difference in surface energy between the pure polymers and their blends. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Relaxation dynamic and electrical mobility for poly(methyl methacrylate)‐polyaniline composites

Composites of emeraldine form of polyaniline (PAni) and poly(methyl methacrylate) (PMMA) are prepared by emulsion polymerization method in definite ratios. The chemical structure of the samples and their morphologies have been investigated by different techniques including FTIR, UV–vis, XRD, SEM, and TGA. Enhancement in thermal stability of the obtained composites by PAni additions has been confirmed. Alpha analyzer, in frequency range 0.1 Hz to 20 MHz, was employed to investigate the molecular dynamics of the prepared samples and the accompanied electrical conductivity at temperatures ranging from 223 to 423 K. Conductivity investigations showed that mobility has the more dominant effect on the charge transportation. The dynamic peak at lower temperatures of the PMMA has high activation energy (83.8 kJ/mol). While, Maxwill‐Wagner‐Siller process due to the interfacial polarization in the composites has only 7.5 kJ/mol activation energy. This is a clear indication of the ease of the investigated dynamic. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45415.     

Synthesis,characterization, and comparison of polyurethane dispersions based on highly versatile anionomer,ATBS, and conventional DMPA

Polyurethane dispersions (PUDs) are one such class of coatings that comply well with stringent VOC regulations. In this study, PUDs were prepared as aqueous dispersions using a new highly versatile crosslinkable anionomer, 2-acrylamido 2 methylpropanesulfonic acid (ATBS), which is commercially available, yet not explored by the coating industry. The influence of this novel anionomer on the performance properties of polyurethane resins was evaluated by comparing performance/properties of this newly synthesized PUD with dispersion based on conventional anionomer, DMPA. Analyses of their physico-chemical and thermo-mechanical properties revealed that PUD based on ATBS showed comparatively much better thermal, mechanical, and chemical and coating properties than the PUD based on DMPA anionomer.     

Evaluation of the Suitability of Agriglasses Containing ZnO for Plant Fertilization

Six different samples from borosilicate and phosphate glassy systems have been synthesized. Glass batches were prepared from chemically pure materials and melted in platinum or porcelain crucibles and at temperatures in the range 1,000–1,450 °C for 2-3 h until homogeneity was reached. The prepared specimens were annealed at the appropriate temperatures of 380 or 520 °C for the phosphate and borosilicate glasses, respectively. Samples of 2 mm dimensions were tested for dissolution behavior in 2% citric acid solution for 1, 2, 3, and 4 weeks and the released phosphorous and potassium ions (macroelements) and zinc ions (microelement) were measured. Also, Infrared (IR) absorption spectra of the samples were measured before and after immersion in the leaching solution. The experimental results indicate that the release of the macroelements and microelements depends primarily on the composition of the agriglass and the percent of constituent ions and the released ions vary slightly from 1 week to 4 weeks. The IR spectra show characteristic IR absorption bands due to vibrations of collective silicate, phosphate, and borate groups, depending on the agriglass composition and the chains or units seem to be interconnected with each other within the glass network. The interpretation of the dissolution behavior is based on a suggested mechanism for the release of the easily soluble components from the glass specimens. The IR absorption spectra support and confirm the proposed behaviour for the corrosion mechanism.     

Rice Bran Oil Improves Insulin Resistance by Affecting the Expression of Antioxidants and Lipid‐Regulatory Genes

The present study investigated the molecular effects of rice bran oil (RBO) on lipid‐regulatory genes (sterol regulatory element binding protein‐1 [Srebf1] and peroxisome proliferator‐activated receptors‐α [Ppara]) and the expression of catalase (CAT) and superoxide dismutase (SOD1) genes in insulin‐resistant rats. Rats were divided into five groups: animals that received standard diet (control); rats fed standard diet containing RBO as the sole source of fat (RBO); a high‐fructose diet (HFD) group, which was further divided into two subgroups: rats fed HFD either for only 1 month (HFD1) or for 2 months (HFD2) and rats fed HFD containing RBO for 1 month; while rats in the last group fed HFD for 30 days then treated with RBO for another 30 days. The HFD induced a state of insulin resistance (IR) as indicated by the hyperinsulinemia and elevated homeostasis model assessment insulin resistance index. Hepatic lipid levels and radical scavenging enzymes were altered by the HFD. Lipid‐regulatory genes, Srebf1 and Ppara, were upregulated while Sod1 and Cat were downregulated in insulin‐resistant rats. Addition of RBO to the two diet regimens alleviated the disorders of IR to some extent. RBO reduced the hepatic levels of triacylglycerol, malondialdehyde, SREBP, and PPAR‐α mRNA. Hepatic SOD and CAT were elevated at gene and protein levels. The HFD induces de novo lipogenesis by upregulating the lipid‐regulatory genes resulting in increased serum and hepatic triacylglycerol. Moreover, IR induced by the HFD caused a state of oxidative stress. Supplementation of RBO to fructose‐fed rats not only improves insulin resistance but also downregulates lipogenic genes and improves the unbalanced oxidative status.     

In situ preparation of magnetic Fe3O4.Cu2O.Fe3O4/cryogel nanocomposite powder via a reduction–coprecipitation method as adsorbent for methylene blue water pollutant

Magnetic nanocomposites have attracted great attention as adsorbents for the removal of water pollutants, which respond to an external magnet that is used to remove both pollutants and composite nanomaterial traces from water. They are environmentally friendly and effective adsorbents for water treatment. In this respect, a simple in situ preparation method was used to prepare cryogel powder composite based on Fe₃O₄.Cu₂O.Fe₃O₄ nanomaterials. The ionic cryogel based on 2‐acrylamido‐2‐methylpropane sulfonate sodium salt and styrene sulfonate sodium salt was prepared by crosslinking polymerization at low temperature. The new magnetic nanoparticles based on Fe₃O₄.Cu₂O.Fe₃O₄ were successfully prepared inside the cryogel networks by a simple reduction–coprecipitation method based on reaction of Fe³⁺ with sodium sulfite and Cu²⁺ in the presence of hydroxylamine and ammonia solution. The thermal stability, accurate Fe₃O₄.Cu₂O.Fe₃O₄ content, magnetic properties, crystal lattice structure, particle sizes and morphology of the prepared cryogel composite were evaluated. The optimum conditions such as pH, contact time, adsorbate concentrations, adsorption equilibrium and adsorption kinetics were investigated to determine the efficiency of the prepared composite as an adsorbent to remove toxic methylene blue (MB) pollutant from aqueous solution. The data for MB adsorption confirmed the high ability of the prepared composite to remove more than 4.696 mmol L^?1 of MB from water during 6 min. The regeneration and reuse experiments showed excellent data for the synthesized new dye as an effective adsorbent for water treatment. © 2018 Society of Chemical Industry     

Gamma irradiation of (styrene butadiene rubber)/(devulcanized waste rubber) blends modified by organoclay

In this study, the physicomechanical properties and morphology evolution of irradiated (styrene butadiene rubber)/(devulcanized waste rubber)/(organically modified montmorillonite) nanocomposites were realized. The improvement in the physicomechanical properties provides a possible mechanism on how organically modified montmorillonite influences the general properties of irradiated nanocomposites. X‐ray diffraction data illustrated that there is an increase in the basal spacing of sodium montmorillonite clay due to modification and/or polymer intercalation. The results of mechanical properties showed that the as‐prepared nanocomposites have superior irradiation‐resistant properties to the (styrene butadiene rubber)/(devulcanized waste rubber) blend. J. VINYL ADDIT. TECHNOL., 24:50–57, 2018. © 2015 Society of Plastics Engineers     

Weighted Version of Extended Nearest Neighbors

This paper investigates the problem of stability analysis for switched complex dynamical networks with mixed time-varying delays and parameter uncertainties. The switched complex dynamical networks are composed of m modes that are switched from one to another based on time, state, etc. Although, the active subsystem is known in any instance, but the switching law such as transition probabilities are not known. The model for each mode is considered affine with matched and unmatched perturbations. The main purpose of the addressed problem is to design a filter error for the switched complex dynamical networks such that the dynamics of the error converges to the asymptotically irrespective of the admissible parameter variations with the gains. Then, by utilizing the Lyapunov functional method, the stochastic analysis combined with the matrix inequality techniques, a sufficient condition in terms of linear matrix inequalities is presented to ensure the $$H_\infty $$ performance of the complex dynamical system models. Finally, a numerical example is presented to illustrate the effectiveness of the proposed design method.     

Coping with adults' angry behavior: Behavioral, physiological, and verbal responses in preschoolers.

This study replicated and extended a study of Cummings (1987) by examining 4- and 5-year-olds' behavioral and verbal responses to adults' angry behavior and collected data on physiological responses. We found behavioral and verbal responses of distress and that systolic blood pressure increased in response to anger. As in Cummings (1987), children's behavioral emotional responses to anger predicted other aspects of responding. Angry/ambivalent children showed a complex heart rate pattern, including a decrease with the onset of anger, whereas heart rate increased in response to anger for concerned/distressed children. Both groups reported more emotional distress (mostly anger) than unresponsive children, and angry–ambivalent children reported the most nonplay responses (e.g., leave, mediate). The results provide more support for discrete patterns of responding to adults' angry emotions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parent Functioning in Families of Preadolescents With Spina Bifida: Longitudinal Implications for Child Adjustment.

The purpose of this study was to test a strength-of-association model regarding possible longitudinal and bidirectional associations between parent functioning and child adjustment in families of children with spina bifida (n = 68) and families of able-bodied children (n = 68). Parent functioning was assessed across 3 domains: parenting stress, individual psychosocial adjustment, and marital satisfaction. Child adjustment was indexed by teacher-reported internalizing and externalizing symptoms, self-reported depressive symptoms, and observed adaptive behavior. Findings revealed that all 3 parent functioning variables predicted child adjustment outcomes, and that such results were particularly strong for externalizing symptoms. Associations between parent functioning and child adjustment tended to be in the direction of parent to child and were similar across both groups. These findings have implications for potential interventions targeted at helping families manage the transition into early adolescence in families of children with spina bifida as well as families of healthy children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)