bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation, characterization and in vitro drug release properties of polytrimethylene carbonate/polyadipic anhydride blend microspheres
Authors: Dinarvand Rassoul , Alimorad Mohammed Massoud , Amanlou Massoud , Akbari Hamid 
Published: May 2006

AbstractPolyadipic anhydride (PAA), an aliphatic polyanhydride, and polytrimethylene carbonate (PTMC), an aliphatic polycarbonate, were synthesized via ring opening polymerization of oxepan‐2,7‐dione and melt‐condensation of trimethylene carbonate (1,3 dioxan‐2‐one), respectively. PTMC–PAA blend microspheres containing different ratios of buprenorphine HCl (2, 5, and 10%) were prepared by an oil‐in‐oil emulsion solvent removal method. Microspheres with different ratios of PTMC–PAA (85/15, 70/30, and 55/45) containing 5% buprenorphine HCl were prepared. Microspheres were spherical with visible cracks and pores on the surface. The average particle size of microspheres was around 200 μm for all microspheres. Drug loading efficiency of PTMC–PAA microspheres (85/15, 70/30, and 55/45) was 97.2, 95.2, and 70.2%, respectively. With the increase in the PTMC ratio, the melting point and the enthalpy of melting were both decreased. The mechanism for drug release from PTMC–PAA blend microspheres were generally a combination of drug diffusion through polymers and biodegradation of the polymers. In first three days, the release from microspheres followed zero order kinetics and was dependent on the PAA content. After three days the drug release from microspheres followed first order kinetics. In conclusion it was demonstrated that buprenorphine HCl release from microspheres could be successfully controlled by using different ratios of PTMC–PAA blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2377–2383, 2006
Microwave promoted grafting of acrylonitrile onto Cassia siamea seed gum
Authors: Singh Vandana , Tripathi Devendra N. 
Published: May 2006

AbstractCassia siamea seed polysaccharide was grafted with acrylonitrile under microwave (MW) irradiation without adding any radical initiator or catalyst. Free radicals are generated here due to the dielectric heating caused by the localized rotation of the hydroxyl groups at the polysaccharide backbone and initiate grafting. To obtain the optimal conditions for the microwave promoted grafting, effect of reaction variables such as monomer/seed gum concentration; MW power and exposure time on the graft copolymerization was studied and the maximum %grafting (%G) and %efficiency (%E) observed were 150% and 43.54%, respectively. The representative graft copolymer was characterized by Fourier transform‐infrared, Thermogravimetric analysis and X‐ray diffraction measurement, taking C. siamea gum as reference. At the same monomer concentration, K2S2O8/ascorbic acid initiated grafting onto the seed gum could result into 80% grafting with 23.22% efficiency. Various properties of the MW synthesized grafted gum like water/saline retention, water retention after saponification and viscosity of the gum solutions were studied. The results have been compared with the conventionally synthesized grafted gum and the parent gum. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2384–2390, 2006
Copolymerization of N‐aryl substituted itaconimide with methyl methacrylate: Effect of substituents on monomer reactivity ratio and thermal behavior
Authors: Chauhan Rashmi , Choudhary Veena 
Published: May 2006

AbstractThe article describes the synthesis and characterization of N‐(4‐methoxy‐3‐chlorophenyl) itaconimide (MCPI) and N‐(2‐methoxy‐5‐chlorophenyl) itaconimide (OMCPI) obtained by reacting itaconic anhydride with 4‐methoxy‐3‐chloroanisidine and 2‐methoxy‐5‐chloroanisidine, respectively. Structural and thermal characterization of MCPI and OMCPI monomers was done by using 1H NMR, FTIR, and differential scanning calorimetry (DSC). Copolymerization of MCPI or OMCPI with methyl methacrylate (MMA) in solution was carried out at 60°C using AIBN as an initiator and THF as solvent. Feed compositions having varying mole fractions of MCPI and OMCPI ranging from 0.1 to 0.5 were taken to prepare copolymers. Copolymerizations were terminated at low percentage conversion. Structural characterization of copolymers was done by FTIR, 1H NMR, and elemental analysis and percent nitrogen content was used to calculate the copolymer composition. The monomer reactivity ratios for MMA–MCPI copolymers were found to be r1 (MMA) = 0.32 ± 0.03 and r2 (MCPI) = 1.54 ± 0.05 and that for MMA–OMCPI copolymers were r1 (MMA) = 0.15 ± 0.02 and r2 (OMCPI) = 1.23 ± 0.18. The intrinsic viscosity [η] of the copolymers decreased with increasing mole fraction of MCPI/or OMCPI. The glass transition temperature as determined from DSC scans was found to increase with increasing amounts of OMPCI in copolymers. A significant improvement in the char yield as determined by thermogravimetry was observed upon copolymerization. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2391–2398, 2006
Fast online acquisition and analysis for parison swell and sag in blow molding
Authors: Huang Han‐Xiong , Li Jiong‐Cheng 
Published: May 2006

AbstractIt is critical to quantitatively and reliably characterize the effects of swell and sag phenomena on the final parison dimensions in extrusion blow molding. To achieve this goal, an online image acquisition and analysis technique was developed. The successive images of parison were automatically taken using the online acquisition apparatus. These images were then analyzed by the combined use of the conventional digital image processing method and the new one developed by the authors. So the development of parison diameter and thickness swells with the extrusion time could be determined online. On the basis of the online obtained actual swell values, the pure swell and sag components were quantitatively determined. The developed technique was tested through a series of experiments using several resins under different processing parameters and die types. Shown in the present article were the results for a converging die under three different die gaps and a high‐density polyethylene. Some new phenomena were observed using the proposed technique. The results showed that the technique yields fast and accurate determination of the evolution of diameter, thickness, and length of parison during its extrusion. The technique can be employed as a part of the closed loop control for blow molded part thickness. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2399–2406, 2006
Effect of solution concentration on the properties of nanocomposites
Authors: Maiti Madhuchhanda , Bhowmick Anil K. 
Published: May 2006

AbstractThough a large number of nanocomposites prepared by solution process has been reported in the literature, effect of solution concentration on properties of the nanocomposites has not been studied. In the present work, new fluorocarbon–clay nanocomposites were prepared by a solution mixing process. Characterization of the nanocomposites was done with X‐ray diffraction technique and atomic force microscopy. Effects of different rubber‐solution concentrations (5, 10, 15, 20, and 25 wt %) on the mechanical and dynamic mechanical properties of the resultant nanocomposites were investigated. Optimum properties were achieved at 20 wt % solution. The data could be explained with the help of structure of the nanocomposites and dispersion of the clay. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2407–2411, 2006
Synthesis, characterization, and ligating behavior of poly[N,N‐p‐phenylene bisacryl (methacryl)amide]
Authors: Al‐Fulaij Othman A. , Elassar Abdel‐Zaher A. , El‐Dissouky Ali 
Published: May 2006

AbstractMonomers of diacylated amine were synthesized by the reaction of acryloyl chloride or methacryloyl chloride with p‐phenylenediamine. Heating DMF solution of these monomers at 75°C in the presence of AIBN as an initiator gave the corresponding polymer. The solid metallopolymer complexes with different metal salts were isolated either by the in situ addition of the monomer, metal salt, and initiator at 75°C or by the reaction of the isolated polymer with the metal salt at 150°C. The monomers, polymers, and their metallopolymer compounds were characterized using elemental analysis, IR, NMR (1H and 13C), and MS spectral measurements in addition to thermal analysis. The IR data showed that the coordinating atoms of the polymer are dependent on the reaction temperature. The ion selectivity of the isolated polymers toward different metal ions either for a single metal ion or in a mixture as aqueous solutions are studied by the batch techniques. Energy dispersive spectroscopy (EDS) measurements showed that both polymers are more selective to Hg2+ and Pb2+. The morphology of the polymers and their metallopolymer complexes at different temperature was also studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2412–2422, 2006
The tensile properties of strain‐crystallizing vulcanizates. II. Stress relaxation and hysteresis
Authors: Van Der Horst M. , McGill W. J. , Woolard C. D. 
Published: May 2006

AbstractStress relaxation on cessation of extension and hysteresis were examined in conventional and peroxide vulcanizates over a range of crosslink densities at room temperature and at 90°C. The rate of relaxation decreases with an increase in temperature and is attributed to slower nucleation of strain‐induced crystallites. The decrease in the volume fraction of extendable material as a result of strain‐induced crystallites has only a small effect on the rate at which the slope of the stress–strain curve rises. Crystallites that form on cooling, melt on heating, leaving an unaltered network, but when strain‐induced crystallites are melted by heating, they do not reform on cooling. The relaxed network now extends further before failure than a network in which extension was not interrupted by a heating–cooling cycle. This supports proposals in the preceding article that strain‐induced crystals increase tensile properties by altering the network deformation pattern and not by the deflection of propagating flaws, whose mechanism would require the heated sample to fail earlier due to its lower crystalline content. Hysteresis increases sharply at strains at which crystallization in the network becomes possible. The hysteresis ratio reaches a plateau value at higher strains. Relaxation affects both the extension and retraction stress–strain curves and it is proposed that hysteresis is determined by differences in the crystallinity during extension and retraction. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2423–2430, 2006
Fabrication and overcoating of divinylbenzene foam shells using dual initiators
Authors: Paguio R. R. , Nikroo Abbas , Takagi Masaru , Acenas Oliver 
Published: May 2006

AbstractDivinylbenzene (DVB) shells with a density of about 100 mg/cc were produced using a dual‐thermal initiator system. New high‐gain designs for direct‐drive ignition at the National Ignition Facility and the OMEGA laser facility at the Laboratory for Laser Energetics require low‐density foam shells such as these. Previous research using a single initiator system produced fragile DVB shells that cracked or imploded during the fabrication process. The dual‐initiator DVB system used in the present study enabled the shells to be robust enough to produce a high yield of intact shells. The two thermal initiators used were azobisisobutyronitrile (AIBN) and another azo‐type initiator, V‐70. The DVB shells were 800–3500 μm in diameter, with shell wall thickness 7%–10% of the diameter. Because the foam shells were porous, a full‐density permeation barrier of poly(vinyl phenol) was developed and deposited on the shells using two techniques to enable the shells to retain gas. The initial results show that the permeation barrier was pinhole free and could hold the gas in a gas‐filled shell. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2523–2529, 2006
Effect of composition on the conductivity and morphology of ligno sulfonic acid sodium salt doped polyaniline
Authors: Jayakannan M. , Amrutha S. R. , Sindhu K. V. 
Published: May 2006

AbstractA systematic approach is developed to study the ligno sulfonic acid sodium salt (LSA) protonation or doping process with polyaniline emeraldine base (Pani‐EB) in organic solvents like dimethyl sulfoxide, and the influence of LSA‐doping on the properties of polyaniline was investigated in detail. The composition of Pani‐EB and LSA was varied in the weight ratio of 1:1 to 1:50 to investigate the effect of the dopant concentration on the conductivity and morphology. The doping process was confirmed by UV–vis and FTIR spectroscopes. The composition analysis indicates that only 50% of the LSA is used for the doping process irrespective of the weight ratio of LSA/Pani‐EB in the feed. The four probe conductivity measurement suggests that the conductivity of the doped samples are increasing with the increase in the ratio of Pani‐EB/dopant composition, and the high conductivity of the doped material was obtained in the range of 1.0 × 10−2 S/cm. Scanning electron microscopy reveals that LSA induces a selective aggregation in the polyaniline chains to produce needlelike or rod‐shape morphology of sizes having ∼0.2 μm diameter and 1 μm length. At very higher amount of LSA, the microrods are completely collapsed and form uniform continuous morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2650–2655, 2006
Preparation of epoxy resin/CaCO3 nanocomposites and performance of resultant powder coatings
Authors: Yu Haojie , Wang Li , Shi Quan , Jiang Song , Jiang Guohua 
Published: May 2006

AbstractEpoxy resin/CaCO3 nanocomposites were prepared by the methods of extruding, solution blending, and in situ and inclusion polymerization, respectively. The contents of nanoparticles in the nanocomposites were varied from 5 wt % to 15 wt %. Powder coatings with different content of nanoparticles were made from the nanocomposites. The results showed that the cupping property and impact resistance decreased with the increase of coating film thickness. The dispersion of nanoparticles in epoxy matrix affected the impact resistance and cupping property of the obtained coating films greatly. The coating films made from the nanocomposite prepared by in situ and inclusion polymerization showed that the best impact resistance and the maximum cupping property was achieved when nano‐CaCO3 content was 5 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2656–2660, 2006
Preparation and properties of sulfonated ETFE‐g‐polyvinyltoluene membranes for application in fuel cells
Authors: Chen Jinhua , Asano Masaharu , Yoshida Masaru , Maekawa Yasunari 
Published: May 2006

AbstractA new polymer electrolyte membrane prepared by radiation grafting of vinyltoluene into poly(ethylene‐co‐tetrafluoroethylene) (ETFE) film and subsequent sulfonation was developed for application in fuel cells. The effect of grafting condition on the degree of grafting was investigated in detail. Results indicated that the degree of grafting can be controlled over a wide range. The grafted films were sulfonated in a chlorosulfonic acid solution to obtain the polymer electrolyte membranes, which were characterized with respect to their use in fuel cells. It is concluded that the substituted methyl group on the vinyltoluene can improve the chemical stability of the resulting membranes, and the crosslinked ETFE‐g‐poly(vinyltoluene‐co‐divinylbenzene) membranes can be proposed for the future development of alternative low‐cost and high‐performance membranes for fuel cells. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2661–2667, 2006
Synthesis and characterization of siloxane copolyesters containing phenylindane linkages
Authors: Waghmare P. B. , Deshmukh S. A. , Idage S. B. , Idage B. B. 
Published: May 2006

AbstractA novel series of siloxane copolyesters containing 1,1,3‐trimethyl‐3‐(p‐hydroxyphenyl)‐5‐indanol (phenylindane bisphenol), diphenyl terephthalate (DPT), diphenyl isophthalate (DPI), and eugenol end‐capped siloxanes in varying ratios were prepared at a temperature range of 200–290°C under reduced pressure using dibutyl tin dilaurate catalyst by melt polycondensation. The siloxane‐containing copolyesters were characterized by infrared and 1H NMR spectroscopy, elemental analysis, solution viscosity, thermogravimetric analysis, differential scanning calorimetry, and X‐ray diffraction. The effect of incorporation of siloxane moiety was studied on the properties of phenyl indane/DPT/DPI coplyester. The glass transition temperatures of copolyesters were decreased from 235 to 124°C by incorporation of 10% eugenol end‐capped siloxane without affecting the thermal properties. All copolyesters were found to be soluble in commonly used organic solvents and had film forming properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2668–2674, 2006
Sound absorption characteristics of polymer microparticles
Authors: Zhou Hong , Li Bo , Huang Guangsu 
Published: May 2006

AbstractA sound absorption material composed of polymer microparticles and polyurethane (PU) foam with certain geometry cavum has been developed. Its sound‐absorbing characteristic was investigated in the impedance tube, according to transfer function method. Measurements show that polymer microparticles have remarkable effect on the absorption performance of the composite material because of their microstructures and features. Several models established for acoustic properties have been adopted to fit the experimental data. The results show that these models fail to predict accurately the acoustic properties of the materials. The sound energy attenuation in polymer microparticles material may most likely consist of two parts, viscous attenuation of air inside the pores and the friction energy caused by the oscillation of polymer particles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2673–2679, 2006
Electrical conductivity and rheology of carbon‐filled liquid crystal polymer composites
Authors: King Julia A. , Morrison Faith A. , Keith Jason M. , Miller Michael G. , Smith Ryan C. , Cruz Mariana , Neuhalfen Amanda M. , Barton Rodwick L. 
Published: May 2006

AbstractOne emerging market for electrically conductive resins is for bipolar plates for use in fuel cells. Adding carbon fillers to thermoplastic resins increases composite electrical conductivity and viscosity. Current technology often adds as much of a single type of carbon filler as possible to achieve the desired conductivity, while still allowing the carbon‐filled thermoplastic matrix material to be extruded and molded into a bipolar plate. In this study, varying amounts of two different types of carbon, one carbon black and one synthetic graphite, were added to Vectra A950RX liquid crystal polymer. The resulting single filler composites were then tested for electrical conductivity and rheological properties. The electrical conductivity followed that typically seen in polymer composites with a percolation threshold at 4 vol % for carbon black and at 15 vol % for synthetic graphite. Over the range of shear rates studied, the viscosity followed a shear‐thinning power law model with power‐law exponent (n − 1) = −0.5 for neat Vectra A950RX and (n − 1) = −0.7 for highly filled composite materials. Viscosity increased with increasing filler volume fraction for all shear rates. The viscosity–enhancement effect was more rapid for the composites containing carbon black when compared with those containing synthetic graphite. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2680–2688, 2006
Thermally bonded nonwoven filters composed of bicomponent polypropylene/polyester fiber. I. Statistical approach for minimizing the pore size
Authors: Wang X. Y. , Gong R. H. 
Published: May 2006

AbstractA statistical approach involving the uniform design of experiments and regression analysis is used to investigate the effects of thermal bonding process parameters, dwell time, thermal bonding temperature, and hot air velocity, on the pore size of three‐dimensional (3D) nonwoven filters. These filters are produced from polypropylene (PP)/polyester (PET) (sheath/core) bicomponent staple fibers. The pore structures of the filter samples were examined using the capillary flow porometer. Results reveal that the statistical approach is effective in identifying the effects of the investigated process parameters on both the bubble point pore diameter and the mean flow pore diameter for the thermally bonded nonwoven filter samples. Under the optimized processing parameters for achieving the minimized pore size, the predicted minimum bubble point pore diameter is 111.12 μm and the predicted minimum mean flow pore diameter is 63.4 μm for the filter sample with the area density of 60 g/m2. They are in good agreement with the experimental values of 111.71 and 60.91 μm, respectively. Microstructure features observed using scanning electron microscope indicate that the effects of the investigated process parameters on the pore size are closely related to the thermal energy delivered to the fibers and the pressure drop acting on the fabrics. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2689–2699, 2006
Effect of compatibilizers on water absorption kinetics of polypropylene/wood flour foamed composites
Authors: Mishra S. , Verma Jagmohan 
Published: May 2006

AbstractPolypropylene (PP)/wood flour foamed composites were prepared by taking PP:wood flour in the ratios of 100 : 0, 90 : 10, 80 : 20, 70 : 30, and 60 : 40 (w/w), with and without compatibilizers like maleic anhydride‐treated wood flour and maleic anhydride‐grafted PP (PPgMA). The foamed composite samples were employed for water swelling at 27°C, 70°C, and in steam. The absorption of water increased with increase in filler contents for all three‐temperature conditions. The maleic anhydride‐treated wood flour and PPgMA showed reduction in water swelling, and the best one was in case of the PPgMA‐foamed composites for respective conditions. Diffusion, sorption, and permeation coefficients were determined to study the absorption kinetics. FTIR spectra were also recorded for 30 wt % of filler loading for all the composites, which showed the effect of compatibilizers on reduction in water absorption in foamed PP/wood flour composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2530–2537, 2006
Characterization studies on aging properties of acetyl ferrocene containing HTPB‐based elastomers
Authors: Dilsiz Nursel , Ünver Alper 
Published: May 2006

AbstractIn composite solid propellants, low‐molecular‐weight species such as burning rate catalysts, plasticizer, etc. which migrate into liner and thermal insulation layers during curing and storage invariably result in poor mechanical and ballistic properties of the propellants. In the present study, the migration of the burning rate catalyst, acetyl ferrocene, was investigated spectrophotometrically (UV–visible) by evaluating the extent of hindrance to such migration after applying a barrier (liner) of various crosslink densities between the additive (HTPB‐TDI‐plasticizer–acetyl ferrocene) and nonadditive (HTPB‐TDI) gumstocks replicating the propellant and insulating layer, respectively. Enhancing the crosslink densities of liner via a trifunctional aziridine crosslinking agent inhibited migration. The aging of additive gumstock was done at 60°C and its mechanical properties and extent of acetyl ferrocene migration were also evaluated and analyzed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2538–2545, 2006