International Journal of Polymer Science The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Recycling of Cooking Oil Waste into Reactive Polyurethane for Blending with Thermoplastic Polyethylene Thu, 08 Oct 2015 14:23:51 +0000 Driven by the need of growing to a more sustainable and environmentally friendly future, this research is started by mixing in-house produced biorenewable polymers (BP) from waste cooking oil with the standard low density polyethylene (LDPE) and high density polyethylene (HDPE) via melt-mixing at low ratios. These mixtures are then compounded via injection molding to produce tensile samples. By using the quality of individual compounds injected, the parameters obtained for all ratios of LDPE/BP were the same with neat LDPE whereas some adjustments were required for the HDPE/BP compounds. The corresponding mechanical behaviors of each ratio were also examined and the results showed that both tensile strength and strain of the LDPE/BP were better than neat LDPE. On the other hand, increasing the BP content in HDPE/BP will increase the toughness of the compound if compared to neat HDPE. Therefore, not only does the presence of BP provide renewable properties, but it also improves the mechanical properties. Moreover, the processing temperature and composition of BP will both influence the quality and mechanical behavior of the product made. Thus, this study may aid any intention on processing these in-house produced polymers by injection molding. Anika Zafiah M. Rus, N. Syamimi M. Salim, and N. Haiza Sapiee Copyright © 2015 Anika Zafiah M. Rus et al. All rights reserved. Effect of Temperature and Catalyst Concentration on Polyglycerol during Synthesis Thu, 08 Oct 2015 09:21:47 +0000 Morphology, molecular weight, polydispersity, functionality, and thermal properties are important characteristics when using polyglycerol as a building block in the development of materials for industrial applications such as hydrogels, surfactants, asphalts additives, cosmetics, pharmaceutical, biomedical, and drug delivery systems. In this study several experimental techniques are used to understand the effect of process variables during synthesis in the catalyzed etherification of glycerol, a coproduct of biodiesel industry. Biobased polyglycerol is a high-valued product, which is useful as building block material because of its remarkable features, for instance, multiple hydrophilic groups, excellent biocompatibility, and highly flexible aliphatic polyether backbone. A connection between polyglycerol characteristics and process variables during synthesis allows the control of glycerol polymerization through reaction conditions. We show that temperature and catalyst concentration can be tuned with the aim of tailoring fundamental polyglycerol parameters including molecular weight, polydispersity, morphology, and functionality. Carolina Ardila-Suárez, Diana Rojas-Avellaneda, and Gustavo E. Ramirez-Caballero Copyright © 2015 Carolina Ardila-Suárez et al. All rights reserved. Synthesis and Characterization of Chemically Cross-Linked Acrylic Acid/Gelatin Hydrogels: Effect of pH and Composition on Swelling and Drug Release Wed, 07 Oct 2015 08:46:27 +0000 This present work was aimed at synthesizing pH-sensitive cross-linked AA/Gelatin hydrogels by free radical polymerization. Ammonium persulfate and ethylene glycol dimethacrylate (EGDMA) were used as initiator and as cross-linking agent, respectively. Different feed ratios of acrylic acid, gelatin, and EGDMA were used to investigate the effect of monomer, polymer, and degree of cross-linking on swelling and release pattern of the model drug. The swelling behavior of the hydrogel samples was studied in 0.05 M USP phosphate buffer solutions of various pH values pH 1.2, pH 5.5, pH 6.5, and pH 7.5. The prepared samples were evaluated for porosity and sol-gel fraction analysis. Pheniramine maleate used for allergy treatment was loaded as model drug in selected samples. The release study of the drug was investigated in 0.05 M USP phosphate buffer of varying pH values (1.2, 5.5, and 7.5) for 12 hrs. The release data was fitted to various kinetic models to study the release mechanism. Hydrogels were characterized by Fourier transformed infrared (FTIR) spectroscopy which confirmed formation of structure. Surface morphology of unloaded and loaded samples was studied by surface electron microscopy (SEM), which confirmed the distribution of model drug in the gel network. Syed Majid Hanif Bukhari, Samiullah Khan, Muhammad Rehanullah, and Nazar Mohammad Ranjha Copyright © 2015 Syed Majid Hanif Bukhari et al. All rights reserved. Experimental Assessment on the Flexural Bonding Performance of Concrete Beam with GFRP Reinforcing Bar under Repeated Loading Mon, 05 Oct 2015 08:38:18 +0000 This study intends to investigate the flexural bond performance of glass fiber-reinforced polymer (GFRP) reinforcing bar under repeated loading. The flexural bond tests reinforced with GFRP reinforcing bars were carried out according to the BS EN 12269-1 (2000) specification. The bond test consisted of three loading schemes: static, monotonic, and variable-amplitude loading to simulate ambient loading conditions. The empirical bond length based on the static test was 225 mm, whereas it was 317 mm according to ACI 440 1R-03. Each bond stress on the rib is released and bonding force is enhanced as the bond length is increased. Appropriate level of bond length may be recommended with this energy-based analysis. For the monotonic loading test, the bond strengths at pullout failure after 2,000,000 cycles were 10.4 MPa and 6.5 MPa, respectively: 63–70% of the values from the static loading test. The variable loading test indicated that the linear cumulative damage theory on GFRP bonding may not be appropriate for estimating the fatigue limit when subjected to variable-amplitude loading. Minkwan Ju and Hongseob Oh Copyright © 2015 Minkwan Ju and Hongseob Oh. All rights reserved. Antioxidant Activity and Functional Properties of Polymerized Whey Products by Glycation Process Sun, 04 Oct 2015 12:51:40 +0000 The antioxidant properties of sweet and acid whey products were incremented by polymerization of their proteins by glycation of whey protein concentrates (WPC) and their hydrolyzates (WPCH) with ribose and glucose in individual experiments under similar concentration. Heating at 50°C during 20 h maximum and pH 7 and pH 9 were used in all tests. The higher activity was found in WPC glycosylates products with ribose at pH 7 and heating during 10–15 h. In comparable form, antioxidant activity in WPCH was incremented by prior hydrolysis to glycation with 25–45% of hydrolysis degree. Further functional properties of whey proteins (solubility, emulsion, and foam) were also improved by the polymerization with ribose. The color of polymerized products due to Maillard reactions was associated with antioxidant activity of each compound; however comparative color in glycosylates products with glucose and ribose did not show this effect. Liliana Ortega, Anabel Romero, Claudia Muro, and Francisco Riera Copyright © 2015 Liliana Ortega et al. All rights reserved. Recovery and Modification of Waste Tire Particles and Their Use as Reinforcements of Concrete Sun, 04 Oct 2015 12:50:31 +0000 Environmental pollution caused by solid wastes is increasing in the last decades; one of these is referred to automotive tires, which are recycled by different methods, including mechanical grinding. One of the most recurrent applications is to use recycled particles as fillers in building materials, as hydraulic concrete. Nevertheless, detrimental values on the mechanical properties are obtained when they are added. For solving these problems, in this work, a novel proposal is to modify the physicochemical properties of the waste automotive tire particles, previously obtained by grinding process, by using gamma irradiation in order to use them as reinforcements of hydraulic concrete. The results show that improvements on the mechanical properties depend of gamma irradiation as well as concentration and size of waste tire particles. Moreover, SEM images are related to mechanical properties; for instance, rough surface of the tire particles changes when applying irradiation; more smooth surfaces are created, due to the cross-linking of polymer chains. Nevertheless, for higher doses, cracks are observed which are produced by scission of the polymer chains. Eduardo Sadot Herrera-Sosa, Gonzalo Martínez-Barrera, Carlos Barrera-Díaz, Epifanio Cruz-Zaragoza, and Fernando Ureña-Núñez Copyright © 2015 Eduardo Sadot Herrera-Sosa et al. All rights reserved. An Experimental Investigation on the Failure Behavior of a Notched Concrete Beam Strengthened with Carbon Fiber-Reinforced Polymer Sun, 04 Oct 2015 11:38:24 +0000 This paper presents an experiment investigation on the failure behavior of a notched concrete beam reinforced with CFRP, by exploring the influences of the length, thickness, and CFRP bonding methods on the ultimate bearing capacity and failure mode. The interfacial shear stress has first been analytically derived and parametric analyses are then made to predict the failure mode. The experiment observation finds that failure mode significantly depends on CFRP length. The brittle fracture occurs only for nonstrengthened beams; the shear failure I mode mainly occurs when CFRP laminate is 100 mm long; the shear failure II mode mainly occurs when CFRP laminate is 200 mm long; and the delamination failure mode mainly occurs when CFRP laminate is 350 mm long. Meanwhile, the thickness and the bonding methods of CFRP also influence the final failure modes in terms of CFRP length. The measurement on ultimate load shows that an increase in the length of CFRP up to 200 mm significantly improves the bearing capacity of the reinforced beam. A comparison between a theoretical analysis and the experimental observation shows a good agreement in terms of failure modes indicating the accuracy and the validity of the experiment. Xia Huang, Jian Wang, Feng Zhang, Song-shan Niu, and Jun Ding Copyright © 2015 Xia Huang et al. All rights reserved. Rheological Properties of Polysaccharides from Longan (Dimocarpus longan Lour.) Fruit Sun, 04 Oct 2015 11:32:56 +0000 Longan polysaccharide (LP) was extracted from longan (Dimocarpus longan Lour.) pulp. The composition and rheological properties were determined by chemical analysis and dynamic shear rheometer. The flow behavior and viscoelastic behavior of longan polysaccharide (LP) solution were investigated by steady shear and small amplitude oscillatory shear (SAOS) experiments, respectively. The result shows that the solution is a pseudoplastic flow in a range of shear rate (1–100 s−1). The rheological behavior of LP was influenced by cations such as Na+ and Ca2+. With an increase of apparent viscosity, and were accompanied by addition of Na+ and Ca2+. Xingxun Liu, Yongyue Luo, Chunjie Zha, Sumei Zhou, Liya Liu, and Lei Zhao Copyright © 2015 Xingxun Liu et al. All rights reserved. Behavior of Full-Scale Porous GFRP Barrier under Blast Loads Sun, 04 Oct 2015 11:24:00 +0000 This research paper is part of the SAS (Security of Airport Structures) Project funded by the European Programme for Critical Infrastructure Protection, whose objective was to develop and deploy a fiber reinforced polymer (FRP) fencing system intended to protect airport infrastructures against terrorist acts. In the paper, the efficacy of the proposed glass FRP discontinuous (porous) barrier under blast loads is presented by showing the results of the blast test campaign conducted on full-size specimens with a focus on the reduction of the blast shock wave induced by the barrier. A simplified model predicting the reduction of the shock wave beyond the barrier is proposed and validated via the experimental data obtained in the project. D. Asprone, A. Prota, G. Manfredi, and A. Nanni Copyright © 2015 D. Asprone et al. All rights reserved. Bond Characteristics of Macro Polypropylene Fiber in Cementitious Composites Containing Nanosilica and Styrene Butadiene Latex Polymer Sun, 04 Oct 2015 11:22:59 +0000 This study evaluated the bond properties of polypropylene (PP) fiber in plain cementitious composites (PCCs) and styrene butadiene latex polymer cementitious composites (LCCs) at different nanosilica contents. The bond tests were evaluated according to JCI SF-8, in which the contents of nanosilica in the cement were 0, 2, 4, 6, 8, and 10 wt%, based on cement weight. The addition of nanosilica significantly affected the bond properties between macro PP fiber and cementitious composites. For PCCs, the addition of 0–2 wt% nanosilica enhanced bond strength and interface toughness, whereas the addition of 4 wt% or more reduced bond strength and interface toughness. The bond strength and interfacial toughness of LCCs also increased with the addition of up to 6% nanosilica. The analysis of the relative bond strength showed that the addition of nanosilica affects the bond properties of both PCC and LCC. This result was confirmed via microstructural analysis of the macro PP fiber surface after the bond tests, which revealed an increase in scratches due to frictional forces and fiber tearing. Jae-Woong Han, Ji-Hong Jeon, and Chan-Gi Park Copyright © 2015 Jae-Woong Han et al. All rights reserved. Inverse Emulsion Polymerization for the Synthesis of High Molecular Weight Polyacrylamide and Its Application as Sand Stabilizer Sun, 04 Oct 2015 11:14:53 +0000 Polyacrylamides constitute a class of polymers that can entirely dissolve or swell in water to form a solution or hydrogel, respectively. Free radical polymerization of acrylamide monomer, using both solution and inverse emulsion polymerization, was applied to produce polyacrylamide with various molecular weights. This investigation was focused on the production of polymers with varying molecular weight, depending on monomer to initiator ratio. Experimental conditions were designed to produce high molecular weight polymers that can be used in stabilization of sand dunes in the arid regions. Synthesized polyacrylamide samples were characterized using Gel Permeation Chromatography and solution viscosity in order to determine the molecular weights and molecular weights distribution. The rheological behavior was also investigated in different polymer concentrations and at various temperatures using Brookfield Rheometer. Lab-scale wind tunnel was used to determine the stability of the sand before and after treatment with the polymer. Compressive stress-strain test was also used to establish the mechanical behavior of the polymer-sand composite under controlled compressive load up to failure. The results showed that the use of high molecular weight polymer gave excellent mechanical and thermal stability. Mahmoud A. Mohsin and Nuha F. Attia Copyright © 2015 Mahmoud A. Mohsin and Nuha F. Attia. All rights reserved. Interface Bond Characterization between Fiber and Cementitious Matrix Sun, 04 Oct 2015 10:01:22 +0000 The use of high performance composite fibers allows for the improvement of the mechanical properties of cement composites. Previous research results indicate that the mechanical properties of such composites are determined predominantly by the interface properties between the fiber and cementitious matrix. Many researchers have conducted single-fiber pull-out tests using cementitious composites to quantify the interfacial properties between the fiber and cement matrix. This paper aims to establish a design methodology that employs coefficients to represent the design parameters for the interfacial properties for three types of fibers: carbon fiber, polypropylene fiber, and twisted wire strand steel cord. The parameters for each type of fiber include the water-to-binder ratio and fiber embedment length. The adopted equation used for the numerical analysis was calibrated using experimental data, and design coefficients are proposed accordingly. The developed models could be validated successfully, and the pull-out characteristics of each fiber type are presented. Won-Chang Choi, Seok-Joon Jang, and Hyun-Do Yun Copyright © 2015 Won-Chang Choi et al. All rights reserved. Evaluation of Microcrystalline Chitosan and Fibrin Membranes as Platelet-Derived Growth Factor-BB Carriers with Amoxicillin Sun, 04 Oct 2015 09:09:23 +0000 The aim of this study was to describe the mechanical and sorption features of homogeneous and composite membranes which consist of microcrystalline chitosan (MCCh) and fibrin (Fb) in various proportions as well as the in vitro kinetics of platelet-derived growth factor-BB (PDGF-BB) released from ten types of membranes in the presence or absence of amoxicillin (Am). The films were characterized by Fourier transform infrared (FTIR) spectroscopy, mechanical tests: breaking strength (Bs) and elongation at break (Eb), as well as SEM images, and swelling study. The influence of the form of samples (dry or wet) on Young’s modulus (E) was also examined. The homogeneous MCCh (M1) and composite M3 and M4 (MCCh : Fb = 2 : 1 and 1 : 1) membranes were characterized by good sorption properties and higher mechanical strength, when compared with Fb (M2) membrane. Connecting MCCh with Fb decreases release of PDGF-BB and increases release of Am. The most efficient release of PDGF-BB was observed in the case of M4 (the optimum MCCh : Fb ratio was 1 : 1) membrane. It was found that the degree of PDGF-BB release from the membrane is influenced by the physicochemical and mechanical characteristics of the films and by its affinity to growth factor PDGF-BB. Kazimiera H. Bodek, Karolina M. Nowak, Marcin Kozakiewicz, Andrzej Bodek, and Marta Michalska Copyright © 2015 Kazimiera H. Bodek et al. All rights reserved. A Review on Natural Fiber Reinforced Polymer Composite and Its Applications Thu, 01 Oct 2015 16:05:46 +0000 Natural fibers are getting attention from researchers and academician to utilize in polymer composites due to their ecofriendly nature and sustainability. The aim of this review article is to provide a comprehensive review of the foremost appropriate as well as widely used natural fiber reinforced polymer composites (NFPCs) and their applications. In addition, it presents summary of various surface treatments applied to natural fibers and their effect on NFPCs properties. The properties of NFPCs vary with fiber type and fiber source as well as fiber structure. The effects of various chemical treatments on the mechanical and thermal properties of natural fibers reinforcements thermosetting and thermoplastics composites were studied. A number of drawbacks of NFPCs like higher water absorption, inferior fire resistance, and lower mechanical properties limited its applications. Impacts of chemical treatment on the water absorption, tribology, viscoelastic behavior, relaxation behavior, energy absorption flames retardancy, and biodegradability properties of NFPCs were also highlighted. The applications of NFPCs in automobile and construction industry and other applications are demonstrated. It concluded that chemical treatment of the natural fiber improved adhesion between the fiber surface and the polymer matrix which ultimately enhanced physicomechanical and thermochemical properties of the NFPCs. Layth Mohammed, M. N. M. Ansari, Grace Pua, Mohammad Jawaid, and M. Saiful Islam Copyright © 2015 Layth Mohammed et al. All rights reserved. Investigations on the Structural and Mechanical Properties of Polyurethane Resins Based on Cu(II)phthalocyanines Thu, 01 Oct 2015 13:57:26 +0000 This work report was reported on the effect of the addition of organic filler, that is, 2(3),9(10),16(17),23(24)-octahydroxycopper(II)phthalocyanine [(OH)8CuPc] (3), on the thermal, tensile, and morphological properties of a polyurethane matrix. The mechanical and dynamic mechanical thermal tests together with microstructural characterization of CuPc/PU composites were performed. The three PU composite films containing up to 1, 15, and 30 wt% of CuPc have different behaviors in terms of their morphological issues, thermal properties, and tensile behavior in comparison with the PU film as the reference material. Very high elongations at break from 910% to 1230%, as well as high tensile strengths, illustrate excellent ultimate tensile properties of the prepared samples. The best mechanical and thermomechanical properties were found for the sample filled with 30 wt% of CuPc. Tamer E. Youssef, Hamad Al-Turaif, and AbdulAziz A. Wazzan Copyright © 2015 Tamer E. Youssef et al. All rights reserved. Mixture Design Approach on the Physical Properties of Lignin-Resorcinol-Formaldehyde Xerogels Thu, 01 Oct 2015 13:32:04 +0000 Organic xerogels were functionalized by incorporating sugarcane bagasse lignin from soda pulping black liquor, not used so far in this materials, with the aim of introducing new functional groups on traditional gels that could improve its adsorptive capacity. Two mixing designs were applied to identify the reactive combinations that allow a well gel formation and to adjust models that predict physical properties. The designs study five components: resorcinol (, 0.04–0.3), lignin (, 0.004–0.14), formaldehyde (, 0.08–0.17), water (, 0.45–0.8), and NaOH (, 0.0003–0.0035). The first experimental design was an extreme vertices design and its results showed shrinkage between 4.3 and 59.7 and a bulk density from 0.54 to 1.3; a mass ratio near 1.5 was required for gel formation. In the second design a D-Optimal was used to achieve better adjusted coefficients and incorporate the largest possible amount of lignin in the gels. Bulk density varies from 0.42 to 0.9, shrinkage varies from 3.42 to 25.35, and specific surface area reaches values of 451.86 m2/g with 13% lignin and 270 m2/g with 27% lignin. High catalyst content improves lignin dissolution and increase shrinkage and bulk density of xerogels and bulk density. Lignin contributes to reducing shrinkage and specific surface area due to his compact and rigid structure. Chris D. Castro and Germán C. Quintana Copyright © 2015 Chris D. Castro and Germán C. Quintana. All rights reserved. Phase Transition of Waxy and Normal Wheat Starch Granules during Gelatinization Thu, 01 Oct 2015 13:15:37 +0000 The phase transition of waxy and normal wheat starches was systematically studied by light microscopy (LM) with a hot-stage, confocal laser scanning microscopy (CLSM) and differential scanning calorimetry (DSC). While being heated in water, waxy wheat starch showed a higher gelatinization enthalpy than that for the normal starch, which was also verified by the changes in birefringence. As confirmed by LM and CLSM, starch granules displayed an increased swelling degree with temperature increasing, and the gelatinization initially occurred at the hilum (botanical center) of the granules and then spread rapidly to the periphery. While the temperature range of birefringence was narrower than that of granule size change, the crystalline structure was melted at lower temperatures than those for the molecular orders. These results indicate that starch gelatinization was a complex process rather than a simple order-to-disorder granule transition. Pei Chen, Xingxun Liu, Xiao Zhang, Parveen Sangwan, and Long Yu Copyright © 2015 Pei Chen et al. All rights reserved. Behavior and Performance of GFRP Reinforced Concrete Columns with Various Types of Stirrups Thu, 01 Oct 2015 11:36:21 +0000 Fiber reinforced polymer (FRP) composites are gaining acceptance in concrete structural applications due to their high ratio of strength/stiffness to self-weight and corrosion resistance. This study focused on the structural behavior and the performance of concrete columns internally reinforced with glass fiber reinforced plastic (GFRP) rebars. Twelve series of concrete columns with varied longitudinal reinforcement, cross section, concrete cover, and type of lateral reinforcement were tested under compression loading. The results show that the amount of GFRP longitudinal and lateral reinforcement slightly affects the column strength. The lateral reinforcement affects the confining pressure and inelastic deformation, and its contribution to the confined compressive strength increases with the GFRP reinforcement ratio. In addition, the confining pressure increases both concrete strength and deformability in the inelastic range. The confinement effectiveness coefficient varied from 3.0 to 7.0 with longitudinal reinforcement. The average deformability factors were 4.2 and 2.8 with spirals and ties, respectively. Lateral reinforcement had a more pronounced effect on deformability than on column strength. Woraphot Prachasaree, Sitthichai Piriyakootorn, Athawit Sangsrijun, and Suchart Limkatanyu Copyright © 2015 Woraphot Prachasaree et al. All rights reserved. Characterization of Jatropha curcas L. Protein Cast Films with respect to Packaging Relevant Properties Thu, 01 Oct 2015 11:02:45 +0000 There is increasing research ongoing towards the substitution of petrochemical based plastics by more sustainable raw materials, especially in the field of bioplastics. Proteins of different types such as whey, casein, gelatine, or zein show potential beyond the food and feed industry as, for instance, the application in packaging. Protein based coatings provide different packaging relevant properties such as barrier against permanent gases, certain water vapour barrier, and mechanical resistance. The aim of this study was to explore the potential for packaging applications of proteins from Jatropha curcas L. and to compare the performance with literature data on cast films from whey protein isolate. As a by-product from oil extraction, high amounts of Jatropha meal are obtained requiring a concept for its sustainable utilization. Jatropha seed cake includes up to 40% (w/w) of protein which is currently not utilized. The present study provides new data on the potential of Jatropha protein for packaging applications. It was shown that Jatropha protein cast films show suitable barrier and mechanical properties depending on the extraction and purification method as well as on the plasticiser content. Based on these findings Jatropha proteins own potential to be utilized as coating material for food packaging applications. Gabriele Gofferje, Markus Schmid, and Andreas Stäbler Copyright © 2015 Gabriele Gofferje et al. All rights reserved. Shear Flow Induced Alignment of Carbon Nanotubes in Natural Rubber Wed, 30 Sep 2015 13:55:04 +0000 A new procedure for the fabrication of natural rubber composite with aligned carbon nanotubes is provided in this study. The two-step approach is based on (i) the preparation of mixture latex of natural rubber, multiwalled carbon nanotubes, and other components and (ii) the orientation of carbon nanotubes by a flow field. Rubber composite sheets filled with variable volume fraction of aligned carbon nanotubes were fabricated and then confirmed by transmission electron microscopy and Raman spectroscopy studies. An obvious increase in thermal conductivity has been obtained after the alignment of carbon nanotubes. The dynamic mechanical analysis was carried out in a tear mode for the composite. Yan He, Zhifang Cao, and Lianxiang Ma Copyright © 2015 Yan He et al. All rights reserved. Effects of Elevated Temperatures on the Compressive Strength Capacity of Concrete Cylinders Confined with FRP Sheets: An Experimental Investigation Wed, 30 Sep 2015 09:00:18 +0000 Due to their high strength, corrosion resistance, and durability, fiber reinforced polymers (FRP) are very attractive for civil engineering applications. One of these applications is the strengthening of concrete columns with FRP sheets. The performance of this strengthening technique at elevated temperature is still questionable and needs more investigations. This research investigates the effects of exposure to high temperatures on the compressive strength of concrete cylinders wrapped with glass and carbon FRP sheets. Test specimens consisted of 30 unwrapped and 60 wrapped concrete cylinders. All specimens were exposed to temperatures of 100, 200, and 300°C for periods of 1, 2, and 3 hours. The compressive strengths of the unwrapped concrete cylinders were compared with their counterparts of the wrapped cylinders. For the unwrapped cylinders, test results showed that the elevated temperatures considered in this study had almost no effect on their compressive strength; however, the wrapped specimens were significantly affected, especially those wrapped with GFRP sheets. The compressive strength of the wrapped specimens decreased as the exposure period and the temperature level increased. After three hours of exposure to 300°C, a maximum compressive strength loss of about 25.3% and 37.9%, respectively, was recorded in the wrapped CFRP and GFRP specimens. Sherif El-Gamal, Khalifa Al-Jabri, Ahmed Al-Mahri, and Saud Al-Mahrouqi Copyright © 2015 Sherif El-Gamal et al. All rights reserved. Modification of Urushiol Derivatives by Liquid Crystal Epoxy Resin Sun, 30 Aug 2015 08:29:48 +0000 Urushiol derivatives have vast potentials for using as coating materials. However, the cured coatings are quite brittle, limiting their applications. In this study, urushiol-furfural (UFUR) was chosen as an example of urushiol derivatives and a liquid crystal (LC) epoxy resin, tetramethylbiphenyl diglycidyl ether (TMBPDE), was for the first time utilized to modify UFUR. Fourier transform infrared spectroscopy and solid-state 13C nuclear magnetic resonance showed the reactions between TMBPDE and UFUR after the UFUR/TMBPDE composite resin was cured. Differential scanning calorimetry analysis showed that the significantly increased after the addition of TMBPDE. Thermogravimetry analysis indicated that the cured UFUR/TMBPDE composite resin exhibited increasing thermodecomposition temperature as the TMBPDE concentration increased, indicating its great potential for high temperature applications. Moreover, the presence of TMBPDE enhanced the toughness of UFUR as observed by impact test and reflected in the morphologies observed from SEM images of fracture surfaces. It would also be novel and effective to modify urushiol derivatives by the LC polymer. Gongwen Tang, Zhishan Yan, Linrong Ma, and Xin Huang Copyright © 2015 Gongwen Tang et al. All rights reserved. Enzymatic Digestion and Mass Spectroscopies of N-Linked Glycans in Lacquer Stellacyanin from Rhus vernicifera Sun, 30 Aug 2015 06:17:22 +0000 Lacquer stellacyanin was isolated and purified from lacquer acetone powder by continuous Sephadex column chromatographies using Sephadex C-50, DEAE A-50, and C-50 gels. The purified lacquer stellacyanin had a blue color with one major and three minor bands around 26 k Dain SDS PAGE. Trypsin- and chymotrypsin-treated lacquer stellacyanins were examined by LC/MS/MS to determine three N-glycosylation sites (N28, N60, and N102) and were further analyzed by MALDI TOF MS, indicating that the N-linked glycans were attached to the three asparagine (Asn) sites, respectively. In addition, after trypsin digestion and PNGase A and PNGase F treatments to cleave N-linked glycans from the Asn sites, it was found that lacquer stellacyanin had a xylose containing a biantennary N-linked glycan with core fucosylation consisting of 13 sugar residues (a complex type N-linked glycan) by MALDI TOF MS analysis. This is the first report on the structure of an N-linked glycan in lacquer stellacyanin. Oyunjargal Tumurbaatar and Takashi Yoshida Copyright © 2015 Oyunjargal Tumurbaatar and Takashi Yoshida. All rights reserved. Preparation and Characterization of Urushiol Methylene Acetal Derivatives with Various Degrees of Unsaturation in Alkyl Side Chain Thu, 27 Aug 2015 14:04:47 +0000 Preparation of urushiol derivatives was carried out in response to the drug industry’s increasing demand for new synthetic anticancer agents. Urushiol methylene acetal derivatives were synthesized in high yields by reaction of urushiol with methylene chloride under the catalytic action of NaOH. Four kinds of urushiol methylene acetal monomers were separated by silica-gel column and preparative HPLC, and their structures were elucidated by extensive spectroscopic methods, including 1D-NMR and 2D-NMR (1H, 13C-NMR, 1H-1HCOSY, HSQC, and HMBC) as well as TOF-MS. They were identified as 3-[pentadecyl] benzene methylene ether (compound 1), 3-[8′-pentadecatrienyl] benzene methylene ether (compound 2), 3-[8′,11′-pentadecatrienyl] benzene methylene ether (compound 3), and 3-[8′,11′,14′-pentadecatrienyl] benzene methylene ether (compound 4). This research provides a theoretical reference for exploration of these interesting and potentially bioactive compounds. Chengzhang Wang, Yuanfeng He, Hao Zhou, Ran Tao, Hongxia Chen, Jianzhong Ye, and Yusi Zhang Copyright © 2015 Chengzhang Wang et al. All rights reserved. Simultaneous Organic and Inorganic Analysis of Colored Oriental Lacquerware by Pyrolysis-Gas Chromatography/Mass Spectrometry Thu, 27 Aug 2015 13:52:44 +0000 Organic analysis and inorganic analysis are generally based on different physical principles, and for this reason it is difficult to analyze resins and pigments simultaneously. For these reasons, we have performed Py-GC/MS measurements of red-, yellow-, and green-colored lacquer films applied to lacquerware items to assess the feasibility of simultaneously detecting resin ingredients together with certain pigments. We have also compared our findings to the results of SEM-EDS, X-ray fluorescence spectrometry (XRF), and X-ray diffractometry (XRD) measurements. XRD analysis yielded molecular-level information (information on binding states) regarding mercury (Hg) and iron (Fe); however, the information obtained for arsenic (As) and sulfur (S) was insufficient. In contrast, Py-GC/MS analyses simultaneously yielded molecular-level information on arsenic (As) and sulfur (S) together with detection of the primary ingredients of the lacquer. For this reason, it shows that several pieces of information is provided easily and quickly when the colored lacquer cultural heritage is measured using the Py-GC/MS method. Yoshimi Kamiya, Takayuki Honda, Atsushi Ohbuchi, and Tetsuo Miyakoshi Copyright © 2015 Yoshimi Kamiya et al. All rights reserved. Properties of Polymer-Composite Used as Fills of Asian Lacquerware: Issues on Restoration Processes of Lacquered Objects from Cultural Heritage Thu, 27 Aug 2015 13:47:05 +0000 One of the common problems encountered in lacquerware issued from cultural heritage is the appearance of lifting areas and some losses of material. Composite systems made of commercial polymer and different fills were tested as filling agents for the cracking, splitting, and losses compensation of Asian lacquer. For that purpose, the stability of traditional and modern commercially available materials usually used in the restoration practice of historical lacquerware was assessed. Their thermomechanical and chemical properties and surface state were evaluated by a set of techniques (TGA, DMA, mechanical test, contact angle value, and microtopography). There is a drastic change of the behavior of the interface between fill and Asian lacquer, dependent on the nature of the composite fillers. So the evaluation of materials and processes for the restoration of Asian lacquer were emphasized. The commercial Paraloid B72 used with glass microspheres as additives appeared to be the most stable of all of the investigated fillers. Anne-Solenn Le Hô, Isabelle Fabre-Francke, and Caroline Thiphavong Copyright © 2015 Anne-Solenn Le Hô et al. All rights reserved. Polymerization of Oriental Lacquer (Urushi) with Epoxidized Linseed Oil as a New Reactive Diluent Thu, 27 Aug 2015 13:43:54 +0000 A hybrid lacquer (HBL) paint prepared by combining a natural kurome lacquer (KL) paint and an amino silane reagent, for example, N-(2-aminoethyl)-3-aminopropyl triethoxysilane (AATES), produced a polymerized film faster than the KL paint alone. However, the viscosity of the HBL paint was too viscous for easy handling. Addition of 10 wt% of an epoxidized linseed oil, ELO-6, with 6.4 mol% epoxidation as a reactive diluent to the HBL paint decreased the viscosity by 1/2 from 25476 mPas to 12841 mPas and improved the ease of coatability. The polymerization mechanism was elucidated by NMR measurements of extracts from the resulting polymerization films, suggesting that amino groups in the HBL paint reacted with epoxy groups of ELO-6 in the lacquer matrix, and then the complex reacted with double bonds of the urushiol side-chain by autooxidation and cross-linking reactions to give a hard polymerized film with a high quality of color and gloss. These results indicate that the addition of ELO-6 improved the polymerizability of both KL and HBL paints without decreasing the quality of the resulting films. Takahisa Ishimura and Takashi Yoshida Copyright © 2015 Takahisa Ishimura and Takashi Yoshida. All rights reserved. Prepolymerization of Lacquer Sap under Pure Oxygen Atmosphere and Its Effects on the Properties of Lacquer Film Thu, 27 Aug 2015 13:17:23 +0000 A series of lacquer saps were prepared by prepolymerization under oxygen atmosphere. The prepolymerization process was investigated by GPC, UV-Vis, FT-IR, NMR, and microscope. The results showed that the polymerization of urushiol monomer was accelerated. The content of monomer in the lacquer sap swiftly decreased from 82.68% to 47.75% in 0.5 h. The mechanism of polymerization was complex and was involved in the coupling reaction of phenyl ring, the addition reaction of the unsaturated carbon-carbon double bond groups with urushiol hydroxyl groups, and other reactions that occurred on the side chains. In addition, the prepolymerization also improved significantly the drying property of lacquer film, especially at low relative humidity. At the same time, the sizes of the water drops in the lacquer saps significantly decreased with increasing the stirring time and the surface of lacquer film became smoother, which resulted in its excellent gloss (109–125). Due to the prepolymerization, the pencil hardness and the thermal stability of lacquer film were slightly improved as well. Jianhong Yang, Jianfeng Zhu, Wanghui Liu, Jianping Deng, and Yuanyuan Ding Copyright © 2015 Jianhong Yang et al. All rights reserved. Characterization of Vietnamese Lacquer Collected in Different Seasons Thu, 27 Aug 2015 13:12:43 +0000 Vietnamese lacquers collected every month from June to March of next year were characterized. Composition analysis showed that lacquer collected in rainy season contained much water, while those collected in dry season contained more lipid component. Although hardness of lacquer films is not very hard, lacquers tapped in all seasons can reach hard dry (HD) within 48 hours. Refining lacquer can accelerate drying time but the water concentration should be maintained around 10 wt% for laccase activity. Rong Lu, Kenichiro Anzai, Bach Trong Phuc, and Tetsuo Miyakoshi Copyright © 2015 Rong Lu et al. All rights reserved. Use of Rubber Process Analyzer for Characterizing the Molecular Weight Parameters of Natural Rubber Wed, 26 Aug 2015 13:33:18 +0000 The aim of this work is to introduce a simple and rapid method for characterizing the molecular weight parameters and other molecular structure parameters of natural rubber (NR) using a rubber process analyzer (RPA). In this work, NR of different molecular weights was prepared by milling. Molecular weight parameters were measured by gel permeation chromatography coupled with laser light scattering (GPC-LLS) for comparison with RPA results. It was verified that increasing of milling time leads to a decrease of the number-average molecular weight (), weight-average molecular weight (), and molecular weight distribution (MWD). The dynamic and rheological properties were evaluated on RPA by tests of strain sweep, frequency sweep, and stress relaxation. These results were used to characterize the average molecular weight, MWD, and viscosity of NR and were found to agree with those from GPC-LLS. This convenient and rapid technology for characterizing NR molecular weight parameters would be especially useful in the elastomer industry. Tianming Gao, Ruihong Xie, Linghong Zhang, Hongxing Gui, and Maofang Huang Copyright © 2015 Tianming Gao et al. All rights reserved.