http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Sun, 19 May 2013 16:19:40 +0000 http://www.hindawi.com/journals/ijps/2013/825296/ The optical and bactericidal properties of acetic and basic chitosan films were studied. By the ORD technique, we found that these films differed in the values of their specific optical rotation and of their rotary and dispersive constants. A sign inversion of was observed when the acetic chitosan films were heat-treated. The bactericidal activity of the initial and dehydrated acetic films was analyzed, and their moisture content and optical and biological activities were compared. A. B. Shipovskaya, V. I. Fomina, D. A. Rudenko, and S. Yu. Shchyogolev Copyright © 2013 A. B. Shipovskaya et al. All rights reserved. Wed, 08 May 2013 14:04:56 +0000 http://www.hindawi.com/journals/ijps/2013/514951/ This research work focuses on the processability and mechanical characterization of blends of polylactic acid (PLA) and tire (elastomeric part). Wasted tires used as filler in the PLA matrix were reduced by two different processes (thermal shock and pyrolysis) in order to acquire the solid residuals in powder to be characterized and compared. Elastomeric solids obtained from scraped tires were used as filler in the PLA matrix and mixed in a Brabender 60 cc mixer at different concentrations ranging from 0% to 60% of filler volume fraction. The blend was laminated, and then samples were obtained in order to undertake mechanical properties at tension and Izod impact tests. A fully detailed analysis on the solid powders by Differential Scanning Calorimeter (DSC), thermogravimetric analysis (TGA), infrared analysis (IR), and scanning electron microscopy analysis (SEM) identified them as a rich source of carbon. Blends were characterized thermally and mechanically showing a direct effect due to the tire nature (thermoset rubber) and concentration. Fracture mechanisms were also identified. Carlos Rolando Rios-Soberanis, Shuchi Wakayama, Takenobo Sakai, José de los Ángeles Rodriguez-Laviada, and Emilio Pérez-Pacheco Copyright © 2013 Carlos Rolando Rios-Soberanis et al. All rights reserved. Wed, 24 Apr 2013 14:29:27 +0000 http://www.hindawi.com/journals/ijps/2013/397027/ A water soluble branched cationic polyacrylamide (BCPAM) was synthesized using solution polymerization. The polymerization was initiated using potassium diperiodatocuprate, K5[Cu(HIO6)2](Cu(III)), initiating the self-condensing vinyl copolymerization of acrylamide and acryloxyethyltrimethyl ammonium chloride (DAC) monomer. The resulting copolymer was characterized by the use of Fourier-transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. Its flocculation properties were evaluated with standard jar tests of sewage. The effects of initiator concentration, monomer concentration, reaction temperature, and the mass ratio of monomers on intrinsic viscosity and flocculation properties of the product were determined using single-factor experiments and orthogonal experiment. Weimin Sun, Guangcheng Zhang, Ling Pan, Helin Li, and Aihua Shi Copyright © 2013 Weimin Sun et al. All rights reserved. Mon, 08 Apr 2013 13:20:24 +0000 http://www.hindawi.com/journals/ijps/2013/451398/ Decoloring methyl orange (MeOr) under sunlight was conducted in a photocatalytic membrane reactor (PMR). Zinc oxide nanoparticles (ZnO NPs) were suspended in the solution or immobilized on the membrane. The membrane was modified by grafting 2-hydroxyethyl methacrylate (HEMA) to enhance the adsorption of ZnO NPs on the hydrophobic membrane surface and improve the membrane permeability. The results show that the water fluxes through the modified membranes are higher than that through the unmodified membrane. After introducing ZnO NPs to the membrane, the water fluxes still rise with the immobilization degree of ZnO NPs. For the PMR with ZnO NPs in suspension, the photocatalytic decoloration percent (PDP) was over 98.2% after 40 min under sunlight. For the PMR with ZnO NPs immobilized on the membrane, the max of PDP was 74.3% after 6 h under sunlight, and maintained at 72% after repeated uses for five times. These results demonstrate that photocatalytic membrane reactor (PMR) based on ZnO NPs and polypropylene macroporous membrane(PPMM) could be applied in decoloring dyes. Bing Hu, Jin Zhou, and Xiu-Min Wu Copyright © 2013 Bing Hu et al. All rights reserved. Thu, 04 Apr 2013 14:08:40 +0000 http://www.hindawi.com/journals/ijps/2013/256161/ The purpose was to interpret the varying morphology of electrospun cellulose acetate (CA) fibres produced from single and binary solvent systems based on solubility parameters to identify processing conditions for the production of defect-free CA fibrous webs by electrospinning. The Hildebrand solubility parameter () and the radius of the sphere in the Hansen space () of acetone, acetic acid, water, N,N-dimethylacetamide (DMAc), methanol, and chloroform were examined and discussed for the electrospinning of CA. The Hildebrand solubility parameter () of acetone and DMAc were found to be within an appropriate range for the dissolution of CA. The suitability of the binary solvent system of acetone: DMAc (2 : 1) for the continuous electrospinning of defect-free CA fibres was confirmed. Electrospun webs exhibited improved tensile strength and modulus after heat and alkali treatment (deacetylation) of the as-spun material, and no major fibre morphological degradation occurred during the deacetylation process. B. Ghorani, S. J. Russell, and P. Goswami Copyright © 2013 B. Ghorani et al. All rights reserved. Thu, 27 Dec 2012 18:18:10 +0000 http://www.hindawi.com/journals/ijps/2012/972541/ Novel soluble polyimides having long-chain alkyl groups on their side chain were synthesized via polymer reaction with the polyimides having phenolic OH groups and 3,4,5-tris(dodecyloxy)benzoic acid (12GA) using N,N′-dicyclohexylcarbodiimide (DCC) as a dehydration reagent. The polyimides having phenolic OH groups were synthesized from the tetracarboxylic dianhydrides such as 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (cyclohexene-DA), 4,4′-hexafluoroisopropylidendi(phthalic anhydride) (6FDA), and 3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride (DSDA) and aromatic diamines such as 4,4′-diamino-3,3′-dihydroxybiphenyl (HAB). The polymer reactions were carried out in NMP and the progresses of polymer reactions were quantitatively monitored by 1H NMR measurements (conversion; 12.2–98.7%). The obtained polyimides bearing long-chain alkyl groups have enough molecular weights, good film-forming ability, good solubility for various organic solvents, and enough thermal stability. The water contact angles of the polyimide films were investigated, and it is noted that the introduction of long-chain alkyl groups increases the hydrophobicity of polyimide surface. These polyimides are expected to be applicable as the functional materials for microelectronics such as the alignment layers of LCDs. Yusuke Tsuda, Yuki Matsuda, and Takaaki Matsuda Copyright © 2012 Yusuke Tsuda et al. All rights reserved. Mon, 17 Dec 2012 10:49:31 +0000 http://www.hindawi.com/journals/ijps/2012/453821/ Yoshiro Kaneko, E. Bryan Coughlin, Takahiro Gunji, Maki Itoh, Kimihiro Matsukawa, and Kensuke Naka Copyright © 2012 Yoshiro Kaneko et al. All rights reserved. Mon, 17 Dec 2012 10:26:53 +0000 http://www.hindawi.com/journals/ijps/2012/692604/ Arrays of iron oxides as precursors of iron clusters were prepared by oxygen plasma treatment of block copolymer microphase-separated nanostructures in thin films. Block copolymers composed of ferrocene-containing and silsesquioxane-containing polymethacrylate (PMAPOSS-b-PMAHFC) were successfully prepared, with different molecular weights and compositions and narrow molecular weight distributions, by living anionic polymerization. The formed microphase-separated nanostructures in the bulk were characterized by wide- and small-angle X-ray scattering (WAXS and SAXS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Thin films were prepared from a solution of PMAPOSS-b-PMAHFC in tetrahydrofuran by spin coating onto silicon wafers. Fingerprint-type line nanostructures were formed in the PMAPOSS-b-PMAHFCs thin films after solvent annealing with carbon disulfide. Oxygen plasma treatment provided the final line arrays of iron oxides based on the formed nanostructural patterns. Raita Goseki, Tomoyasu Hirai, Masa-aki Kakimoto, and Teruaki Hayakawa Copyright © 2012 Raita Goseki et al. All rights reserved. Thu, 06 Dec 2012 15:58:05 +0000 http://www.hindawi.com/journals/ijps/2012/484523/ Our recent results on the synthesis and properties of a novel family of polysilsesquioxanes having oligothiophenes were reviewed. The polymers anchored on SiO2 or ITO substrates showed excellent mechanical hardness due to the formation of a three-dimensional siloxane network structure and chemical linkage between polymer and the surface of metal-oxide substrates. Optical, electrochemical, and electrical properties of polymers were also investigated. Ichiro Imae, Shotaro Takayama, Daisuke Tokita, Yousuke Ooyama, Kenji Komaguchi, Joji Ohshita, and Yutaka Harima Copyright © 2012 Ichiro Imae et al. All rights reserved. Tue, 04 Dec 2012 09:22:03 +0000 http://www.hindawi.com/journals/ijps/2012/684278/ This paper deals with our recent studies on the preparation of ionic silsesquioxanes (SQs) with regular structures. Cationic ladder-like polySQs (PSQs) with hexagonally stacked structures were successfully prepared by the sol-gel reactions of amino group-containing organotrialkoxysilanes in strong acid aqueous solutions. Self-organization of an ion pair (a salt) prepared from the amino group in the organotrialkoxysilane and an acid is the key factor for the formation of such regular structures of the PSQs. It is also reported that the control of the conformational structure of the PSQs was performed by the introduction of the chiral moieties. In addition, we investigated the correlation between the of acid-catalysts and the structures of SQs prepared by the hydrolytic condensation of amino group-containing organotrialkoxysilane, that is, the use of the superacid aqueous solution resulted in the formation of cage-like octaSQ, while the ladder-like PSQs with hexagonally stacked structures were formed from the strong acid aqueous solutions under the same reaction conditions. Furthermore, anion-exchange behaviors of the cationic ladder-like PSQ were investigated with various organic and inorganic compounds, such as anionic surfactants, a polymer, and layered clay minerals, to obtain the functional hybrid materials. Yoshiro Kaneko, Hisaya Toyodome, Miki Shoiriki, and Nobuo Iyi Copyright © 2012 Yoshiro Kaneko et al. All rights reserved. Thu, 29 Nov 2012 15:59:37 +0000 http://www.hindawi.com/journals/ijps/2012/967276/ In this study the influence of fullerenes in concentrations from 0.5 to 1.5 phr on both the vulcanization characteristics of the compounds and physicomechanical, dynamic, and dielectric properties and thermal aging resistance of nanocomposites on the basis of natural rubber has been investigated. The effect of the filler dispersion in the elastomeric matrix has been also investigated. Neat fullerene and the composites comprising it have been studied and characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Omar A. Al-Hartomy, Ahmed A. Al-Ghamdi, Falleh Al-Salamy, Nikolay Dishovsky, Desislava Slavcheva, and Farid El-Tantawy Copyright © 2012 Omar A. Al-Hartomy et al. All rights reserved. Tue, 27 Nov 2012 15:37:07 +0000 http://www.hindawi.com/journals/ijps/2012/852063/ Printable organic thin-film transistor (O-TFT) is one of the most recognized technical issues nowadays. Our recent progress on the formation of organic-inorganic hybrid thin films consists of polymethylsilsesquioxane (PMSQ), and its applications for the gate-insulating layer of O-TFTs are introduced in this paper. PMSQ synthesized in toluene solution with formic acid catalyst exhibited the electric resistivity of higher than 1014 Ω cm after thermal treatment at 150°C, and the very low concentration of residual silanol groups in PMSQ was confirmed. The PMSQ film contains no mobile ionic impurities, and this is also important property for the practical use for the gate-insulating materials. In the case of top-contact type TFT using poly(3-hexylthiophene) (P3HT) with PMSQ gate-insulating layer, the device properties were comparable with the TFTs having thermally grown SiO2 gate-insulating layer. The feasibility of PMSQ as a gate-insulating material for O-TFTs, which was fabricated on a flexible plastic substrate, has been demonstrated. Moreover, by the modification of PMSQ, further functionalities, such as surface hydrophobicity, high permittivity that allows low driving voltage, and photocurability that allows photolithography, could be appended to the PMSQ gate-insulating layers. Kimihiro Matsukawa, Mitsuru Watanabe, Takashi Hamada, Takashi Nagase, and Hiroyoshi Naito Copyright © 2012 Kimihiro Matsukawa et al. All rights reserved. Sun, 11 Nov 2012 09:45:59 +0000 http://www.hindawi.com/journals/ijps/2012/174942/ There remains a substantial shortfall in the treatment of severe skeletal injuries. The current gold standard of autologous bone grafting from the same patient has many undesirable side effects associated such as donor site morbidity. Tissue engineering seeks to offer a solution to this problem. The primary requirements for tissue-engineered scaffolds have already been well established, and many materials, such as polyesters, present themselves as potential candidates for bone defects; they have comparable structural features, but they often lack the required osteoconductivity to promote adequate bone regeneration. By combining these materials with biological growth factors, which promote the infiltration of cells into the scaffold as well as the differentiation into the specific cell and tissue type, it is possible to increase the formation of new bone. However due to the cost and potential complications associated with growth factors, controlling the rate of release is an important design consideration when developing new bone tissue engineering strategies. This paper will cover recent research in the area of encapsulation and release of growth factors within a variety of different polymeric scaffolds. Keith A. Blackwood, Nathalie Bock, Tim R. Dargaville, and Maria Ann Woodruff Copyright © 2012 Keith A. Blackwood et al. All rights reserved. Tue, 06 Nov 2012 16:11:00 +0000 http://www.hindawi.com/journals/ijps/2012/637837/ The current work focuses on fundamental investigations regarding the barrier properties of grafted PVOH layers produced by the Transfer Method. The layers (or papers) used for the different experiments were produced and grafted during the course of this work. Papers with different types of PVOH (different Mowiol types) were produced by coating. Experiments using different parameters (temperature, reaction duration, and concentration) were performed using the Transfer Method. Contact angle measurements and Cobb60 measurements were carried out on the grafted and untreated PVOH layers. Furthermore, the water vapour transmission rate of the PVOH layers was determined. The results of this work showed that the method of chromatogeny or chromatogenic chemistry improves the water vapour barrier properties of grafted PVOH layers enormously. Markus Schmid, Andreas Benz, Camelia Stinga, Daniel Samain, and Klaus Peter Zeyer Copyright © 2012 Markus Schmid et al. All rights reserved. Thu, 01 Nov 2012 11:24:53 +0000 http://www.hindawi.com/journals/ijps/2012/391325/ The insertion reaction of various guest species, such as rare gases (He, Ne, and Ar), cations of group 1 (Li+, Na+, and K+), and anions of group 17 (F− and Cl−) elements, into the Ti analogues of POSS (polyhedral oligomeric silsesquioxanes), Ti-POSS, [HTiO1.5]n ( and 10), has been investigated by ab initio molecular orbital and density functional methods. For each case, the properties of the exohedral and endohedral complexes and transition-state structure connecting them on the potential energy surface and energetics are discussed in comparison with the case of POSS. Furthermore, in order to understand the origin of the stability of these structures, the binding energy () and the energy barrier of the encapsulation are analyzed by an energy decomposition method. As a result, some similarities and differences between Ti-POSS and POSS were explored. Yosuke Komagata, Takaaki Iimura, Nobuhiro Shima, and Takako Kudo Copyright © 2012 Yosuke Komagata et al. All rights reserved. Wed, 31 Oct 2012 13:08:41 +0000 http://www.hindawi.com/journals/ijps/2012/984501/ Highly water-dispersible silsesquioxane/zirconium oxide hybrid nanoparticles (SQ/ZrO2-NPs) were prepared by the following two-step reactions. First, a mixture of 3-aminopropyltrimethoxysilane (APTMOS) and zirconium tetra-n-butoxide (ZTB) was stirred in a mixed solvent of 0.1 mol/L methanolic hydrochloric acid and n-butanol at room temperature, followed by heating in an open system until the solvent was completely evaporated. Then, the aqueous solution obtained by adding water to the resulting product was heated in an open system until the water was completely reevaporated. The products (SQ/ZrO2-NPs) obtained with a feed molar ratio of APTMOS/ZTB of more than 0.3 were dispersed well in water, and their aqueous dispersions were highly transparent, which was confirmed by UV-Vis measurements. In addition, the solid product obtained by drying its aqueous dispersion was redispersed in water. The volume-average particle sizes of SQ/ZrO2-NPs (APTMOS/ZTB ≥ 0.3) were assessed to be ca. 4.6–23.8 nm by dynamic light scattering measurements in water. The theoretical refractive index of the SQ/ZrO2-NP (APTMOS/ZTB = 0.3) was estimated to be 1.66. It was assumed that the water-dispersible property of the SQ/ZrO2-NPs probably originated from the ZrO2-SiO1.5(CH2)3Cl- core-shell structures. Yoshiro Kaneko and Tomoyuki Arake Copyright © 2012 Yoshiro Kaneko and Tomoyuki Arake. All rights reserved. Tue, 30 Oct 2012 09:39:49 +0000 http://www.hindawi.com/journals/ijps/2012/173624/ This paper presents a short overview of recent advances in the design and synthesis of organic-inorganic hybrids using silsesquioxane-based nanoparticles having nanometer size, relatively narrow size distribution, high functionalities, and various characteristic features, mainly focusing on our recent researches related to the subject. A highlight of this paper is the water-soluble silsesquioxane-based nanoparticles, including hydroxyl-functionalized and cationic silsesquioxanes, which were synthesized via the one-step condensation of the bulky triethoxysilane precursors. The design and synthesis of R-SiO1.5/SiO2 and R-SiO1.5/TiO2 hybrids by hydrolytic cocondensation of a triethoxysilane precursor and metal alkoxides are briefly introduced. This paper also deals with recent results in stimuli-responsive hybrids based on the water-soluble silsesquioxane nanoparticles and fluorinated and amphiphilic silsesquioxane hybrids. Hideharu Mori Copyright © 2012 Hideharu Mori. All rights reserved. Thu, 18 Oct 2012 17:34:52 +0000 http://www.hindawi.com/journals/ijps/2012/526795/ Structural characterization of a polymethylsilsesquioxane (PMSQ) and a DT-type methyl silicone resin (MeDT) has been carried out by various instrumental analyses including GPC, NMR, gas chromatography, and gas chromatography-mass spectrometry. Although the PMSQ had a Mw around 5000, the resin contained a significant amount of low molecular weight species consisting of T2 [MeSi(OH)O2/2] and T3 [MeSiO3/2] units, ranging from to including many isomers. One isomer of was isolated of which structure was determined as a cage structure. The species are supposed to consist mainly of cyclotetra- and cyclopentasiloxanes, but presence of strained rings such as cyclotrisiloxane rings also was suggested. In MeDT, species in which the T2 units in the molecules from PMSQ is replaced with D2 [Me2SiO2/2] were found, for example, , suggesting that general silicone resins consist of similar structures as silsesquioxanes. The Mark-Houwink exponent for these methyl resins was ~0.3, indicating the molecular shape to be compact. Investigation on the formation chemistry of the cubic octamers indicates that siloxane bond rearrangement is an important mechanism in the molecule build-up process. Maki Itoh, Fukuyo Oka, Michitaka Suto, Simon D. Cook, and Norbert Auner Copyright © 2012 Maki Itoh et al. All rights reserved. Thu, 04 Oct 2012 11:38:10 +0000 http://www.hindawi.com/journals/ijps/2012/723892/ Laddersiloxanes, that is, ladder silsesquioxanes with defined structures, could be obtained by stepwise synthesis starting from cyclic silanols. These compounds were shown to have high thermal stability. As an extension of the previous work, the first nonacyclic ladder silsesquioxanes were synthesized by the reaction of bicyclic silanol with tricyclic tetrachloride, which were obtained from cyclic silanols. The structure was confirmed by spectral measurements, and the spectral features of a series of ladder polysilsesquioxanes with determined structures were analyzed. Masafumi Unno, Tomoe Matsumoto, and Hideyuki Matsumoto Copyright © 2012 Masafumi Unno et al. All rights reserved. Sat, 29 Sep 2012 11:11:47 +0000 http://www.hindawi.com/journals/ijps/2012/460835/ By combining the micellar templating in nanometer scale with the polymerization-induced phase separation in micrometer scale, ethylene-bridged polysilsesquioxane gels with hierarchical macropores and mesopores are prepared. The difference of mesopore structures depending on the method of the solvent removal has been observed by the X-ray diffraction and the nitrogen adsorption-desorption measurements. During the hydrothermal treatment under the basic condition, the reorganization of the polysilsesquioxane gel network occurred differently depending on the alkoxy group contained in the precursors. From 29Si CP/MAS NMR measurements, it was revealed that the crosslinking density of the hydrothermally treated gels was increased so that the highly ordered mesostructure of the wet gel could be preserved even after the evaporative drying of solvent. Atsushi Mushiake, Kazuyoshi Kanamori, and Kazuki Nakanishi Copyright © 2012 Atsushi Mushiake et al. All rights reserved. Thu, 27 Sep 2012 19:01:04 +0000 http://www.hindawi.com/journals/ijps/2012/568301/ Polysilsesquioxane having an ethoxysulfonyl group as a side chain was synthesized to prepare a proton-conductive film composed of a main chain of siloxane. At first, sodium 4-(2-methylallyloxy)benzenesulfonate was chlorinated with thionyl chloride. Next, hydrosilylation with trichlorosilane was carried out in the presence of platinum catalyst followed by treatment with ethanol. Finally, the hydrolytic polycondensation was carried out to provide poly(3-(4-ethoxysulfonylphenoxy)-2-methylpropyl)silsesquioxane. This polysilsesquioxane was heated to form a free-standing film that was brittle and brown in color. Takahiro Gunji, Kazuki Yamamoto, Akira Tomobe, Noritaka Abe, and Yoshimoto Abe Copyright © 2012 Takahiro Gunji et al. All rights reserved. Tue, 25 Sep 2012 07:55:31 +0000 http://www.hindawi.com/journals/ijps/2012/586594/ A synthetic route to potentially biocidal silsesquioxanes functionalized by quaternary pyridinium functionalities has been developed. N-Alkylation reactions of the precursor compounds 4-(2-(trimethoxysilyl)ethyl)-pyridine (5) and 4-(2-trichloro-silylethyl)pyridine (6) with iodomethane, n-hexylbromide, and n-hexadecylbromide cleanly afforded the corresponding N-alkylpyridinium salts (7–10). The synthesis of a 4-(2-ethyl)pyridine POSS derivative (2) was achieved by capping of the silsesquioxane trisilanol Cy7Si7O9(OH)3 (1) via two different preparative routes. Attempts to use compound 2 as precursor for quaternary pyridinium salt-functionalized POSS derivatives were met with only partial success. Only the reaction with iodomethane cleanly afforded the new N-methylpyridinium salt 12 in high yield, whereas n-hexylbromide and n-hexadecylbromide failed to react with 2 even under forcing conditions. Nataliya Kostenko, Jochen Gottfriedsen, Liane Hilfert, and Frank T. Edelmann Copyright © 2012 Nataliya Kostenko et al. All rights reserved. Wed, 12 Sep 2012 08:11:37 +0000 http://www.hindawi.com/journals/ijps/2012/846710/ Polyaniline salt form (PANI-ES) was synthesized by oxidative polymerization of aniline using potassium persulfate as an oxidant and an acid-exchanged montmorillonite clay called Maghnite-H+ as an effective catalyst. The clay, which was used as a catalyst, was supplied by a local company known as ENOF Maghnia (Western Algeria). The chemical stability of PANI has been investigated by thermogravimetry and differential scanning calorimetry, that a good thermal stability of PANI could be improved by combining PANI with montmorillonite. TGA results illustrated that there were two major stages for weight loss of the ES-form PANI powder sample. The different forms of PANI were characterized by infrared spectroscopy, thermal analysis, and H-NMR spectroscopy and conductivity measurements. Rahmouni Abdelkader, Harrane Amine, and Belbachir Mohammed Copyright © 2012 Rahmouni Abdelkader et al. All rights reserved. Mon, 03 Sep 2012 14:15:10 +0000 http://www.hindawi.com/journals/ijps/2012/290571/ The objectives of the present work were to evaluate the chemical compatibility between coir (Cocos nucifera L.) and cement and to study treatment methods to improve this compatibility. In the inhibition test, cement hydration temperature evolution was measured in the absence and presence of untreated and treated coir fibres (cold water, hot water and NaOH), besides the addition of 4% of CaCl2. The chemical characterization of untreated and treated coir fibres was done by determining the content of extractives, lignin, and holocellulose. The inhibition test graded the untreated fibre as “extreme inhibition,” ratifying the need to provide it a treatment. Treatments done on coir fibres affected positively the compatibility between cement and fibre, reducing the inhibition. The treatments reduced the lignin coir fibres’ and extractives proportion, whose variation was significantly correlated with the reduction of the inhibitory index. These results indicate a possibility for future incorporation of these fibres into the production of mineral composites. Joana M. Ferraz, Cláudio H. S. Del Menezzi, Mario R. Souza, Esmeralda Y. A. Okino, and Sabrina A. Martins Copyright © 2012 Joana M. Ferraz et al. All rights reserved. Mon, 27 Aug 2012 09:22:02 +0000 http://www.hindawi.com/journals/ijps/2012/679252/ This study focused on exploring the feasibility of green composites made from biodegradable and renewable materials as potential alternatives to petroleum polymer composites and understanding the reinforcing mechanisms in composites containing kenaf fibers (KF). KF-reinforced poly(lactide) acid (PLA) composites were made using melt compounding and injection molding, and their properties were compared to that of KF-reinforced polypropylene (PP) composites. The flexural properties and thermomechanical behavior were determined as a function of the fiber content, the crystallization of PLA and PP was studied using X-ray diffraction and differential scanning calorimetry, and the composites’ morphology was investigated using scanning electron microscopy. It was concluded that PLA exhibits higher modulus and Tg compared to those of neat PP. The modulus of the composites at 40 wt% fibers is 6.64 GPa and 2.96 GPa for PLA and PP, respectively. In general, addition of kenaf results in larger property enhancement in PP due to better wetting of the fibers by the low melt viscosity PP and the crystallization behavior of PP that is significantly altered by the fibers. The novelty of this work is that it provides one-to-one comparison of PLA and PP composites, and it explores the feasibility of fabricating green composites with enhanced properties using a simple scalable process. Seong Ok Han, Mehdi Karevan, I. Na Sim, Md A. Bhuiyan, Young Hun Jang, Jonathan Ghaffar, and Kyriaki Kalaitzidou Copyright © 2012 Seong Ok Han et al. All rights reserved. Mon, 18 Jun 2012 18:31:41 +0000 http://www.hindawi.com/journals/ijps/2012/827967/ A novel approach to design chitosan-polyester materials is reported. The method is based on mechanical activation and effective intermixing of the substrates under high pressure and shear deformation in the course of solid-state reactive blending. The marked departure of this approach from previous practice resides on exploitation of a variety of chemical transformations of the solid polymers that become feasible under conditions of plastic flow. Low temperatures (above Tg but below the melting points of the crystalline polymers) are maintained throughout the process, minimizing mechanical and oxidative degradation of the polymers. Morphology as well as structural, mechanical, and relaxation properties of those prepared blends of chitosan with semicrystalline poly(L,L-lactide) and amorphous poly(D,L-lactide-co-glycolide) has been studied. Grafting of polyester moieties onto chitosan chains was found to occur under employed pressures and shear stresses. The prepared polymer blends have demonstrated an amphiphilic behavior with a propensity to disperse in organic solvents that widens possibilities to transform them into promising materials for various biomedical applications. Tatiana A. Akopova, Tatiana S. Demina, Alexander N. Shchegolikhin, Tikhon S. Kurkin, Christian Grandfils, Nikolay S. Perov, Alexander S. Kechekyan, and Alexander N. Zelenetskii Copyright © 2012 Tatiana A. Akopova et al. All rights reserved. Tue, 12 Jun 2012 16:09:51 +0000 http://www.hindawi.com/journals/ijps/2012/959035/ This article presents the effect of increasing weight percentage natural nanoclay additives on the structure, morphology and mechanical properties of nylon-6-blown films. Combination of X-ray diffraction, thermal analysis and microscopy were used to determine nanocomposite film morphology. The nanoclay additives in the films act as nucleating agent facilitates γ-crystalline forms and results in fine grained spherulite with smaller lamellar size. Increase in tensile, burst, and tear strength is observed for films with up to 5% clay loading. Even though microscale property like tensile and tear strength drops at higher add on levels, near-surface nanoscale hardness and toughness of the film keep on increasing. There is a direct correlation between nanoclay additive add on level and increase in surface energy and wetting behavior of films. Raghavendra R. Hegde, Gajanan S. Bhat, and Bhushan Deshpande Copyright © 2012 Raghavendra R. Hegde et al. All rights reserved. Wed, 06 Jun 2012 11:17:49 +0000 http://www.hindawi.com/journals/ijps/2012/454359/ This paper presents a novel approach to reduce the water vapor transmission rate (WVTR) and water absorbance of wheat gluten/paperboard laminates by introducing a hydrophobic component (oleic acid (OA)) into the hydrophilic plasticizer (glycerol). Whereas the paperboard showed immeasurably high WVTR, the laminate with gluten/glycerol yielded finite values. More importantly, by incorporating 75 wt.% OA into the plasticizer, the WVTR and water absorbance were reduced by, respectively, a factor of three and 1.5–2. Of particular interest was that the mechanical properties were not changing dramatically between 0 and 50 wt.% OA. The results showed clear benefits of combining a gluten film with paperboard. Whereas the paperboard provided toughness, the WG layer contributed with improved moisture barrier properties. In addition, WVTR indicated that the paperboard reduced the swelling of the outer gluten/glycerol layer in moist conditions; a free standing gluten/glycerol film would yield infinite, rather than finite, WVTR values. Sung-Woo Cho, Thomas O. J. Blomfeldt, Helena Halonen, Mikael Gällstedt, and Mikael S. Hedenqvist Copyright © 2012 Sung-Woo Cho et al. All rights reserved. Sun, 03 Jun 2012 14:38:52 +0000 http://www.hindawi.com/journals/ijps/2012/168412/ Eri Yoshida, Takashi Kaneko, Toshifumi Satoh, Yusuf Menceloglu, and Atsuyoshi Nakayama Copyright © 2012 Eri Yoshida et al. All rights reserved. Wed, 30 May 2012 09:42:27 +0000 http://www.hindawi.com/journals/ijps/2012/216137/ A long-term absorbable monofilament suture was developed using poly-4-hydroxybutyrate (P4HB) made from a biosynthetically produced homopolymer of the natural metabolite 4-hydroxybutyrate. The suture, called MonoMax, has prolonged strength retention. At 12 weeks, a size 3-0 MonoMax suture retains approximately 50% of its initial tensile strength in vivo and is substantially degraded in one year with minimal tissue reaction. In contrast, PDS II monofilament suture (Ethicon, Inc., Somerville, NJ) has no residual strength in vivo after 12 weeks. In vivo, the MonoMax suture is hydrolyzed primarily by bulk hydrolysis, and is then degraded via the Krebs cycle. MonoMax is substantially more compliant than other monofilament sutures, and incorporates an element of elasticity. Its tensile modulus of 0.48 GPa is approximately one-third of the value of the PDS II fiber providing an exceptionally flexible and pliable fiber with excellent knot strength and security. These features are further enhanced by the fiber's elasticity, which also improves knot security and may help prevent wound dehiscence. Because of its performance advantages, this suture may find clinical utility in applications where prolonged strength retention, and greater flexibility are required, particularly in procedures like abdominal wall closure where wound dehiscence is still a significant post-surgical complication. Erich K. Odermatt, Lutz Funk, Rainer Bargon, David P. Martin, Said Rizk, and Simon F. Williams Copyright © 2012 Erich K. Odermatt et al. All rights reserved.