bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of water‐soluble polyacrylate sodium modified by organomontmorillonite
Authors: Peng Xiaohong , Li Li , Peng Xiaochun 
Published: July 2008

AbstractWater‐soluble high intrinsic viscosity organomontmorillonite modified polyacrylate sodium (OMMT‐modified PNaA) was prepared via an in situ intercalation adiabatic polymerization of sodium acrylate in the presence of OMMT. The FTIR and XRD analyses correspond to the OMMT‐modified PNaA with exfoliated structure of OMMT. The influences of prepared conditions on intrinsic viscosity and dissolving time of the modified polymers had been investigated in this study. It was found that the incorporation of as little as 0.1 wt % of OMMT added to PNaA matrix could be effective to enhance intrinsic viscosity of the modified PNaA. TGA and DSC studies confirmed the enhancement of the thermal stability of the OMMT‐modified PNaA when compared with PNaA. Furthermore, the solution behavior studies of the modified PNaA showed the “antipolyelectrolyte” effect and high “antishearing” property. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, characterization, and biodegradation of carboxymethylchitosan‐g‐medium chain length polyhydroxyalkanoates
Authors: Bhatt Rachana , Panchal Bijal , Patel Kamlesh , Sinha Vijay Kumar , Trivedi Ujjval 
Published: July 2008

AbstractGrafting of medium chain length polyhydroxyalkanoates (mcl‐PHA) produced by Comamonas testosteroni onto carboxymethylchitosan (CMCH) using ceric ammonium nitrate (CAN) as an initiator was carried out under nitrogen atmosphere in aqueous medium. The grafting composition was 2 g CMCH, 0.2M CAN, and 0.5 g mcl‐PHA. The reaction was carried out at 40°C ± 1°C for 4.5 h, and reaction product was extracted by acetone precipitation. The CMCH‐g‐mcl‐PHA copolymers were characterized by Fourier transform infrared spectroscopy, Thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. The data obtained showed successful grafting of mcl‐PHA onto CMCH polymer. TGA results indicated that the graft was stable up to 380°C, and the solubility studies revealed a high % grafting efficiency. Biodegradation studies of the graft in terms of microbial growth, extracellular protein concentration, and % weight loss in the graft were carried out for 30 days using a bacterial isolate Burkholderia cepacia 202 and a fungal isolate Aspergillus fumigatus 202. 93% weight loss of the graft was obtained in case of A. fumigatus 202, whereas B. cepacia 202 showed 76% loss in weight of the graft. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preceramic polymer for SiBNC fiber via one‐step condensation of silane, BCl3, and silazane
Authors: Tang Yun , Wang Jun , Li Xiao‐Dong , Wang Hao , Li Wen‐Hua , Wang Xiao‐Zhou 
Published: July 2008

AbstractA preceramic polymer for SiBNC fiber, polyborosilazane, has been synthesized by one‐step condensation reaction of dichloromethylsilane, BCl3, and hexamethyldisilazane with high yield. The reaction mainly involves the condensation of SiCl and BCl with NSiMe3 followed by SiMe3Cl evaporation and dehydrogenation between NH and SiH. The resulted polymer is a soluble colorless transparent solid with melting point of 70°C and molecular weight of 10,800. The backbone of the polymer is mainly composed of SiNB‐bridge with some borazine rings. The polymer exhibits good processability and flexible polymer fibers with diameter of 15–20 μm were obtained by melt spinning. Pyrolysis of the as‐synthesized polymer to 1000°C under nitrogen atmosphere results in a ceramic yield of 63 wt %, and the obtained SiBNC ceramic remains fully amorphous up to 1700°C, and only small amount of poorly crystallized BN, Si3N4, and SiC phases were observed upon heating at 1850°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Prediction of the twisting moment and axial force in a circular rubber cylinder for combined extension and torsion based on the logarithmic strain approach
Authors: Kakavas P. A. , Giannopoulos G. I. , Vassilopoulos A. P. 
Published: July 2008

AbstractThe scope of the present work is the application of a particular class of strain energy function, based on the logarithmic strain, for the prediction of the twisting moment and axial force of a rubber circular cylinder under combined extension and torsion. The strain energy function involves four material parameters three of which are determined by fitting published experimental data from simple tensile and compression tests of natural rubber. One of the parameters of the proposed model has physical meaning, and it is equal to one ninth of the initial modulus of elasticity of the material. Hence, the number of unknown parameters is reduced to three. The logarithmic strain energy function is then applied to a combined extension and torsion problem of a rubber circular cylinder to check its performance for more complicated deformations. The results are compared with corresponding experimental and theoretical solutions available in the literature to validate the proposed model. It is found that the proposed strain energy function apart from predicting the common modes of deformations is also capable to determine more complicated types of deformation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Nonisothermal and isothermal crystallization kinetics of nylon‐12
Authors: McFerran Neil L. A. , Armstrong Cecil G. , McNally Tony 
Published: July 2008

AbstractThe isothermal and nonisothermal crystallization behavior of Nylon 12 was investigated using differential scanning calorimetry (DSC). An Avrami analysis was used to study the isothermal crystallization kinetics of Nylon 12, the Avrami exponent (n) determined and its relevance to crystal growth discussed and an activation energy for the process evaluated using an Arrhenius type expression. The Lauritzen and Hoffman analysis was used to examine the spherulitic growth process of the primary crystallization stage of Nylon 12. The surface‐free energy and work of chain folding were calculated using a procedure reported by Hoffmann and the work of chain folding per molecular fold (σ) and chain stiffness of Nylon 12 (q) was calculated and compared to values reported for Nylons 6,6 and 11. The Jeziorny modification of the Avrami analysis, Cazé and Chuah average Avrami parameter methods and Ozawa equation were used in an attempt to model the nonisothermal crystallization kinetics of Nylon 12. A combined Avrami and Ozawa treatment, described by Liu, was used to more accurately model the nonisothermal crystallization kinetics of Nylon 12. The activation energy for nonisothermal crystallization processes was determined using the Kissinger method for Nylon 12 and compared with values reported previously for Nylon 6,6 and Nylon 11. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Compatibilization and properties of SAN/EPDM blends with the addition of coagents
Authors: Taheri Mona , Morshedian Jalil , Esfandeh Masoud 
Published: July 2008

AbstractSAN and EPDM are not miscible. In this work, the dry blending of SAN and EPDM using Centrex (acrylonitrile/EPDM/styrene graft copolymer) and EPMMA (EPDM‐g‐Mah) as coagents was studied. Centrex content was used at 6–20 wt %. EPMMA content in the mixture was 20 wt %. The effects of coagent type and content on the mechanical properties and morphology were investigated. SEM micrographs of SAN/EPDM/Centrex and SAN/EPDM/EPMMA blends showed that both Centrex and EPMMA have an effective role in forming a finer morphology. For the ternary blends, the addition of coagent resulted in a significant reduction in the size of the dispersed phase. The mechanical properties of SAN/EPDM/coagent blends were improved significantly in comparison to the simple SAN/EPDM blends. SAN/EPDM/Centrex blends showed higher stress‐at‐break and SAN/EPDM/EPMMA blends showed higher impact strength. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and in situ foaming of biodegradable malonic acid ESO polymers
Authors: Doğan Engin , Küsefoğlu Selim 
Published: July 2008

AbstractIn this study, biodegradable rigid cellular materials were synthesized from the reaction of malonic acid with epoxidized soybean oil. Malonic acid reacts with two epoxy groups to give a network polymer. In the course of this reaction, initially formed malonic acid monoester (MAME) can decarboxylate and produce CO2, which acts as the blowing agent leading to in situ foaming of the polymer. Epoxide addition and decarboxylation reactions of MAME occur competitively and simultaneously and by controlling their relative rates, foams of controlled density were produced. 1H NMR spectrum of the synthesized foams showed that increasing the temperature increases the rate of decarboxylation reaction of MAME and decreases crosslink density leading to softer and lower density foams. Addition of 1,4‐diazabicyclo[2.2.2]octane (DABCO) as a catalyst also increases the rate of decarboxylation. Load deflection curves of the cellular materials showed that decreasing the temperature and addition of DABCO increase compressive modulus of samples. Cell morphology was studied by microscopic images of foam samples that showed that foam samples have a closed cell structure and a wide distribution of cell volume. Soil burial test was done to determine rate of biodegradation of foam samples. A half‐life of 815 days showed that foam samples are highly biodegradable. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of a multistructural film with CM‐chitosan and PVA, and in vitro ornidazole release from the carrier
Authors: Wang Ling Chong , Chen Xi Guang , Sheng Liu Cheng , De Li Li , Xia Ji Qiu , Jun Yu Le 
Published: July 2008

AbstractIn this study, carboxymethyl‐chitosan microspheres (CCMS) were prepared by a method of emulsification combined with two‐step solidification and loaded ornidazole as model drug. The ornidazole loaded CCMS were incorporated into Poly(vinyl alcohol) (PVA) film to form a multistructure drug system for feasibly releasing drug in local site. The appearance, particle size, drug loading and encapsulation efficiency, and drug release profiles of CCMS could be tailored in the preparation. Appropriate enhancement of drug amount in the microsphere would bring optimum effect on drug loading percentage and release profile. The use of dimethylsulfoxide (DMSO) could produce spherical spheres with smooth surface and small size, but depress the drug loading and encapsulation efficiency and hasten the burst drug release. For the multistructure carrier materials, the outer PVA film rapidly breaks up to pieces after about 30 min of placement in water and then entirely dissolved. Drug release from the multistructure carriers was a little faster than that from the pure CCMS. Ornidazole release from the carriers performed a burst release in the initial 2 h then followed a gradual release. It could be achieved the controlled release pattern of ornidazole by dispersing the well prepared CCMS into PVA film. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polymer micro or nanofibers for optical device applications
Authors: Yang Qing , Jiang Xiaoshun , Gu Fuxing , Ma Zhe , Zhang Jiangyang , Tong Limin 
Published: July 2008

AbstractSilica taper incorporated polymer micro or nanofibers have been fabricated by direct drawing. This method could provide stable and high‐optical‐coupling efficiency. The as‐fabricated polymethyl methacrylate (PMMA) fibers not only show low‐optical losses, but also offer good flexibility, making them promising elements for sharp‐bending waveguides and ring resonators. A low‐loss microcoupler has been assembled with two 860‐nm‐diameter PMMA fibers and a polymeric knot resonator with a loaded Q‐factor of about 3000 has been assembled using a 3‐μm‐diameter PMMA microfiber. Thermostability of the PMMA fibers has also been investigated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Comparison of mechanical properties of PP/SEBS blends at intermediate and high strain rates with SiO2 nanoparticles vs. CaCO3 fillers
Authors: Mae Hiroyuki , Omiya Masaki , Kishimoto Kikuo 
Published: July 2008

AbstractThe present article focuses on the effect of two types of inorganic fillers (SiO2 and CaCO3) on the mechanical properties of PP/SEBS blend. The nominal particle diameters of SiO2 and CaCO3 are 7 nm and 1 μm, respectively. The studied blend ratios were PP/SEBS/SiO2 (CaCO3) = 75/22/3 and 73/21/6 vol %. The morphology of polymer blends was observed and the distributions of the SEBS, SiO2, and CaCO3 particles were analyzed by transmission electron microscopy (TEM). Tensile tests were conducted at nominal strain rates from 3 × 10−1 to 102 s−1. The apparent elastic modulus has the local strain‐rate dependency caused by SiO2 nanoparticles around SEBS particles in the blend of PP/SEBS/SiO2. The yield stress has weak dependency of morphology. The absorbed strain energy has strong dependency of the location of SiO2 nanoparticle or CaCO3 fillers and SEBS particle in the morphology. It is considered that such morphology, in which inorganic nanoparticles are located around SEBS particles, can prevent the brittle fracture while the increased local strain rate can enhance the apparent elastic modulus of the blend at the high strain rate. On the basis of the results of this study, the location and size of inorganic nanoparticles are the most important parameters to increase the elastic modulus without decreasing the material ductility of the blend at both low and high strain rates. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Rheology of 1‐butyl‐3‐methylimidazolium chloride cellulose solutions. I. Shear rheology
Authors: Sammons R. J. , Collier J. R. , Rials T. G. , Petrovan S. 
Published: July 2008

AbstractIn this article, shear rheology of solutions of different concentrations obtained by dissolution of cellulose in the ionic liquid (IL) solvent 1‐butyl‐3‐methylimidazolium chloride ([Bmim]Cl) was studied by measuring the complex viscosity and dynamic moduli at different temperatures. The obtained viscosity curves were compared with those of lyocell solutions and melt blowing grade polypropylene melts of different melt flow rates (MFR). Master curves were generated for complex viscosity and dynamic moduli by using Carreau and Cross viscosity models to fit experimental data. From the Arrhenius plots of the shift factors with respect to temperature, the activation energies for shear flow were determined. These varied between 18.99 and 24.09 kCal/mol, and were compared with values for lyocell solutions and different polymeric melts, such as polyolefins, polystyrene, and polycarbonate. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polythiophene gold nanoparticles composite film for application to glucose sensor
Authors: Pandey Pratibha , Arya Sunil K. , Matharu Zimple , Singh S. P. , Datta Monika , Malhotra B. D. 
Published: July 2008

AbstractRegioregular poly‐3‐hexylthiophene (regP3HT) and dithiobissuccinimidyl propionate (DTSP) have been used to prepare bifunctionalized gold nanoparticles (Bf AuNPs). Processable properties of regP3HT have been used to obtain regP3HT‐AuNPs‐DTSP film on a gold‐coated glass surface and the succinimidyl group of DTSP in this regP3HT‐AuNPs‐DTSP/Au electrode has been utilized for covalent immobilization of glucose oxidase (GOx). The UV‐visible (UV‐vis), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopic studies have been used to characterize regP3HT‐AuNPs‐DTSP/Au and GOx‐regP3HT‐AuNPs‐DTSP/Au electrode, respectively. This GOx‐regP3HT‐AuNPs‐DTSP/Au bioelectrode shows response time of 10 s, linearity from 25 to 300 mg/dL of glucose and the value of Michaelis‐Menten constant as 5.85 mM (105.3 mg/dL). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Branched poly(p‐phenylenevinylene): Synthesis, optical and electrochemical properties
Authors: Huo Lijun , Hou Jianhui , Zhou Yi , Han Minfang , Li Yongfang 
Published: July 2008

AbstractA series of poly(p‐phenylene vinylene) (PPV) derivatives with phenylene vinylene side chains (branched PPVs), PPV0, PPV1, PPV2, and PPV3, were synthesized by the Heck coupling reaction and characterized by TGA, absorption spectra, photoluminescence (PL) spectra, and electrochemical cyclic voltammetry. The branched PPVs showed two absorption peaks in the UV–vis region, corresponding to the conjugated side chains (UV absorption) and the main chains (the visible absorption). Especially the absorption spectrum of PPV3 covers a broad wavelength range from 300 to 500 nm. Introducing the electron‐donating alkoxy substituents on the PPV main chains and increasing the content of the alkoxy groups lead to bathochromic shift of both absorption and PL spectra from PPV1 to PPV2 to PPV3. The onset oxidation potential of the branched PPVs is lower by 0.1–0.2 V than that of PPV, indicating that the electron‐donating ability of the branched PPVs enhanced in comparison with that of PPV. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Gas permeation properties of polyvinylchloride/polyethyleneglycol blend membranes
Authors: Sadeghi M. , Pourafshari Chenar M. , Rahimian M. , Moradi S. , Dehaghani A. H. Saeedi 
Published: July 2008

AbstractIn this study, the effect of the molecular weight of polyethyleneglycol (PEG) on the gas permeability and selectivity of a series of polyvinylchloride/polyethyleneglycol (PVC/PEG) blend membranes was investigated. The molecular weight of polyethylene glycol ranged from 400 to 4000. PVC/PEG blend membranes were prepared via thermal phase inversion of PVC/PEG/dimethylformamide solution at 60°C. The permeabilities of pure CO2, CH4, O2, and N2 gases through prepared membranes were determined at room temperature (25°C) and 20 bar feed pressure. The blend membranes having PEG with 4000 molecular weight showed higher values of CO2 permeability, and CO2/CH4 and CO2/N2 ideal selectivities (the ratio of pair gas permeabilities) compared with other blend membranes containing PEGs of lower molecular weights. It was also found that the gas permeabilities of PVC/PEG4000 blend membrane rapidly increased with an increase in PEG concentration (weight fraction). The PVC/PEG blends containing 10, 20, and 30 wt % of PEG4000 showed CO2 permeabilities equal to 0.84, 2.38, and 5.82 Barrer (1 Barrer = 10−10 cm3 (STP) cm/cm2 s cmHg), respectively. The CO2/N2 ideal selectivities of 10, 20, and 30 wt % of PEG4000/PVC blend membranes were 49, 70, and 109, respectively. This is a great improvement compared with the pure PVC membrane, which showed CO2 permeability and CO2/N2 ideal selectivity of 0.13 Barrer and 14.5, respectively. These results and comparison of CH4 and N2 permeabilities of PVC membrane and PVC/PEG blend membranes indicated that the gas solubility is dominant in the permeation of gases through abovementioned blend membranes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and properties of novel soluble polychloro substituted aromatic polyamides
Authors: Sheng Shou‐Ri , Liu Zhuo , Liu Xiao‐Ling , Liu Yan , Song Cai‐Sheng 
Published: July 2008

AbstractA novel monomer of tetrachloroterephthaloyl chloride (TCTPC) was prepared by the chlorination of terephthaloyl chloride catalyzed by ferric chloride at 175–180°C for 10 h, and confirmed by FTIR, MS, and elemental analysis. A series of new polychloro substituted polyamides with inherent viscosities of 1.17–1.28 dL/g have been prepared from TCTPC with various aromatic diamines. All the polyamides were amorphous and readily soluble in polar solvents such as NMP, DMAc, DMF, and DMSO at room temperature, and could afford flexible and tough films via solution casting. The cast films exhibited good mechanical properties with tensile strengths of 83.6–106.8 MPa, elongations at breakage of 3.9–7.1%, and tensile modulus of 2.28–3.98 GPa. These polyamide films also exhibited good thermal stability with the glass transition temperature of 250–284°C, the temperature at 5% weight loss of 470–504°C and high char yields of 57.8–59.7% in nitrogen. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Quantitative Analysis and Localization of mRNA Transcripts of Type I Collagen, Osteocalcin, MMP 2, MMP 8, and MMP 13 During Bone Healing in a Rat Calvarial Experimental Defect Model
Authors: Itagaki Tomoko , Honma Takahiro , Takahashi Ichiro , Echigo Seishi , Sasano Yasuyuki 
Published: July 2008

AbstractThe study examined the expression of matrix metalloproteinases (MMPs), type I collagen and osteocalcin during bone healing in a rat calvarial experimental defect model. Twelve‐week‐old male Wistar rats were used. A full‐thickness standardized trephine defect was made in the parietal bone, with the rat under anesthesia. RNA was extracted from tissue that filled the original bone defect on days 1 and 3 and in weeks 1, 2, 3, 5, 8, 10, 12, 18, and 24 and processed for quantitative analysis of expression of type I collagen, osteocalcin and matrix metalloproteinases (MMPs) 2, 8, and 13 by using real‐time polymerase chain reaction. Alternatively, the rats were fixed by perfusion through the aorta and resected calvaria were processed for in situ hybridization for these molecules. The expression of type I collagen, osteocalcin and MMPs 2 and 13 increased toward week 2 and decreased thereafter, whereas the expression of MMP 8 was the highest on day 1. The mRNA transcripts of type I collagen and osteocalcin were localized in osteoblasts and osteocytes, some of which expressed MMPs 2, 8, and 13. Osteoblasts and osteocytes may play a role in the remodeling of extracellular matrices with MMPs during healing of a defect in bone. Anat Rec, 291:1038–1046, 2008. © 2008 Wiley‐Liss, Inc.
Nasal Fossa of Mouse and Dwarf Lemurs (Primates, Cheirogaleidae)
Authors: Smith Timothy D. , Rossie James B. 
Published: July 2008

AbstractDimensions of the external midface in mammals are sometimes related to olfactory abilities (e.g., “olfactory snouts” of strepsirrhine primates). This association hinges on the largely unexplored relationship between the protruding midface and internal topography of the nasal fossae. Herein, serially sectioned heads of embryonic to adult cheirogaleid primates (mouse and dwarf lemurs) and a comparative sample were studied. To assess the anteroposterior distribution of olfactory epithelium (OE) within the nasal fossa, the surface area of OE and non‐OE was measured in two mouse lemurs (one adult, one infant). Prenatally, ethmoturbinal projections appear in an anteroposterior sequence. Fetal mouse lemurs, tenrecs, voles, and flying lemurs have four ethmoturbinals that project toward the nasal septum. Major distinctions among these mammals include the number of turbinals in recesses and the extent of the olfactory recess. Surface area measurements in the adult mouse lemur reveal that 31% of the entire nasal fossa is lined with OE. The majority is sequestered in a posterior recess (70% OE). Anterior to this space, only 28% of the nasal fossa is lined with OE. Ethmoturbinal I is lined with relatively less OE (35%) compared with more posterior ethmoturbinals (46–57%). Age comparisons support the idea that OE increases less than non‐OE between ages. Regionally, results suggest that most growth in surface area occurs in turbinals. But in all ethmoturbinals, surface area of non‐OE differs between ages more than that of OE. This study shows that the anterior part of the nasal fossa is mostly nonolfactory in Microcebus murinus. Anat Rec, 291:895–915, 2008. © 2008 Wiley‐Liss, Inc.
The Nasal Fossa of Mouse and Dwarf Lemurs (Primates, Cheirogaleidae)
Authors: Smith Timothy D. , Rossie James B. 
Published: July 2008

AbstractVentral view of a computer‐generated, 3D reconstruction of the nasal capsule in a 16 mm CRL Microcebus murinus. The position of the eyes is lateral to the nasal capsule. See Smith et al., Anatomical Record 291:895–915.