bluuebunny/crossref_metadata_2025_split huggingface dataset:
Grafting of maleic anhydride onto styrene–butadiene–styrene triblock copolymer using supercritical CO2 as a swelling agent
Authors: Li Chunsheng , Zhang Shuxiang , Zheng Anna , Kong Xiangzheng , Geng Bing 
Published: September 2006

AbstractGrafting of maleic anhydride (MA) onto styrene–butadiene–styrene triblock copolymer (SBS) was carried out by free radical polymerization using supercritical carbon dioxide (SC CO2) as a solvent of MA and swelling agent of SBS. The effect of various factors such as monomer concentration, initiator concentration, SC CO2 pressure, and reaction time on grafting ratio was studied. SBS and the product (SBS‐g‐MA) were characterized by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). GPC data showed that the molecular weight of SBS‐g‐MA is bigger than that of SBS. DSC testing indicated that the glass transition temperature (Tg) of SBS‐g‐MA is higher than that of SBS. By SEM photo, we can observe that some particles which contain more oxygen atom grew out from the surface of SBS‐g‐MA when grafting ratio reached at 5.6%, and the amount and diameter of particles increased with increasing of grafting ratio. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4425–4429, 2006
Preparation and characterization of polyacrylic acid‐poly(vinyl alcohol)‐based interpenetrating hydrogels
Authors: Hernández Rebeca , López Daniel , Mijangos Carmen 
Published: September 2006

AbstractSome structural features of hydrogels from poly(acrylic acid) (PAAc) of various crosslinking degrees have been investigated through mechanical and swelling measurements. Interpenetrating polymer hydrogels (IPHs) of poly(vinyl alcohol) (PVA) and PAAc have been prepared by a sequential method: crosslinked PAAc chains were formed in aqueous solution by crosslinking copolymerization of acrylic acid and N,N‐methylenebisacrylamide in the presence of PVA. The application of freeze–thaw (F–T) cycles leads to the formation of a PVA hydrogel within the synthesized PAAc hydrogel. The swelling and viscoelastic properties of the IPHs were evaluated as a function of the content of crosslinker and the application of one F–T cycle. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5789–5794, 2006
Studies on fly‐ash‐filled natural rubber modified with cardanol derivatives: Processability, mechanical properties, fracture morphology, and thermal decomposition characteristics
Authors: Menon A. R. R. , Sonia T. A. , Sudha J. D. 
Published: September 2006

AbstractFly ash, a by‐product of thermal power stations, was used as a filler in natural rubber (NR) in presence of 5–10 phr of phosphorylated cardanol prepolymer (PCP) and hexamethylene tetramine cured PCP (PCPHM). The compositions modified with the cardanol‐based resins showed lower power consumption for mixing, lower cure time, improved tensile properties and tear strength, and higher thermal stability. Scanning electron microscopy of the fracture surfaces of the tensile‐failed specimens showed finer and more uniformly distributed filler particles in the rubber matrix in the presence of PCP/PCPHM. The cardanol‐based resins are expected to function as a coupling agent between the filler and rubber leading to the improvement in mechanical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4801–4808, 2006
Urea–formaldehyde–propionaldehyde physical gelation resins for improved swelling in water
Authors: Mansouri H. R. , Pizzi A. 
Published: September 2006

AbstractUrea–formaldehyde (UF) resins' water tolerance and swelling thickness of interior‐grade wood panels bonded with UF resins were improved markedly by introducing small amounts of UFPropanal (UFP) polycondensates into the UF resin. 13C NMR of urea–propanal (UP) resins showed that urea and propanal do react up to the formation of dimers. The water repellancy imparted by insertion in the resin of the alkyl chain of propanal limits the proportion of propanal that can be used. Gel permeation chromatography showed that this appears to be so because UP resins and UFP resins exist as an equilibrium between two separate intermingling phases, namely one in solution and the second in a state of physical gelation. This latter is different from the state of physical gelation observed on ageing or advancement of formaldehyde‐only based polycondensation resins. This physical gelation is brought on by the insertion in the resin of the water repellant chain of the propanal reacted with urea and constitutes a new state of physical gelation of polycondensates other than what was already reported in the literature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5131–5136, 2006
The effect of orientation of various phenols on the degradation kinetics of blends of resole and epoxy
Authors: Srivastava Kavita , Kumar Kaushik Manoj , Srivastava Deepak , Kumar Tripathi Santosh 
Published: September 2006

AbstractResoles were prepared separately with different phenols, with formaldehyde having phenol‐to‐formaldehyde mole ratio of 1:2 in basic medium at 70°C. These resoles were physically blended with different weight percentages of diglycidyl ether of bisphenol‐A (DGEBA)–epoxy resin. The blends were cured with 40, 50, and 60 wt % polyamide (based on total amount of the blended resin). Decomposition kinetics of blend sample was studied by dynamic thermogravimetric (TG) analysis. It was found that the degradation of most of the blend samples followed two‐step second‐order degradation kinetics with 50 wt % polyamide and varied reaction orders with 40 and 60 wt % polyamide and type of phenols used in the resole. The energy of activation (E) was found to be maximum with the blend system containing p‐cresolic resole and epoxy. The value of preexponential factor (Z) decreased when phenolic resole was changed to p‐cresolic resole in the blend. Also, the plotted values of E and Z were found to be in close resemblance with those obtained from calculated values. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4171–4176, 2006
Studies on interfacial adhesion, tensile and thermal characteristics in blends of polystyrene/novalac resin
Authors: Konar B. B. , Ray S. K. , Konar P. B. 
Published: September 2006

AbstractSpecific interactions generate stability of the component parts in blends. Present work aims to elucidate intermolecular interactions in polystyrene/novolac blends by means of Infrared spectroscopic studies. It was found that strong interactions were observed at band 3095 cm−1 assigned to aromatic CH stretching vibrations, at band 2980 cm−1 assigned to aliphatic C‐H stretching vibration and at band 1635 cm−1 assigned to CC stretch vibration of aromatic ring system. Maximum interaction was observed in blend consisting polystyrene/novolac (80:20 by parts, in this study it is blend B). Mechanical and thermal properties of the blends were also studied. Tensile strength data was found maximum in blend B. Nonisothermal method of Freeman and Carrol was used to investigate the kinetics of thermal degradation. The reactions were studied by thermogravimetry in nitrogen atmosphere. Decomposition of the blends was found in consecutive stages. The activation energies were determined for each stage of reactions. From thermal studies, blend B was found to be most stable. A degradation mechanism was suggested by compiling the reports of previous authors. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4630–4636, 2006
Blended resins based on a new propargyl‐functional resin: Synthesis, cure, and thermal properties
Authors: Liu Feng , Li Wanwan , Wei Liuhe , Zhao Tong 
Published: September 2006

AbstractA new propargyl‐functional resin, propargyl ether bisphenol A novolac (PBPN), was synthesized, and the structure of PBPN were characterized using 1H NMR and FTIR spectra. The PBPN was blended with 4,4′‐bismaleimide diphenyl methane (BDM) at different molar ratio to obtain the blends. Differential scanning calorimetry (DSC) was used to characterize the cure behavior of PBPN and the blends. Thermal gravimetric analysis (TGA) and dynamic mechanical analysis (DMA) were performed, respectively, to evaluate thermal stability and dynamic mechanical properties of the cured resins. The results indicate that the PBPN presented better cure and thermal properties than do traditional propargyl resins; furthermore, the cure behavior and thermal properties of PBPN could be improved remarkably by blending with BDM. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4207–4212, 2006
Boric acid binding studies with diol containing polyethylenimines as determined by 11B NMR spectroscopy
Authors: Labouriau Andrea , Smith Barbara F. , Khalsa Guru Rattan K. , Robison Thomas W. 
Published: September 2006

AbstractThree water‐soluble polymers incorporating increasing levels of 2,3‐dihydroxy propyl attached to polyethylenimine (PEI) backbone were synthesized, characterized by NMR, and investigated for their ability to bind boric acid (BA). 11B NMR spectroscopy showed that BA interacted with the polymeric 2,3‐dihydroxy propyls by forming borate monoester and borate diesters in the boron concentration range of 100–1000 ppm and at 0.0775M polymer. Borate monoester species predominated for low functionalization levels (33% of the PEI amines functionalized), whereas borate diester species dominated for the higher functionalized polymers (66–100% of the PEI amines functionalized). All three polymers showed that 100% of the BA was bound as a mixture of borate mono‐ and diesters at 100‐ppm boron. The overall best performer based on total borate ester formation was the 2/3‐PEI, with a binding Kd of 631 at 200 ppm boron. Borate ion concentration was measured from the 11B NMR chemical shift of the BA/borate peak and it decreased as 1/3‐PEI > 2/3‐PEI > 3/3‐PEI. Variable temperature 11B NMR showed drastic reduction of borate ester species at 65°C. Thus, PEI polymers, as the ones investigated in this work, are reasonable candidates for the selective recovery and recycle of BA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4411–4418, 2006
Modeling the chemorheological behavior of epoxy/liquid aromatic diamine for resin transfer molding applications
Authors: Naffakh Mohammed , Dumon Michel , Gérard Jean‐François 
Published: September 2006

AbstractThe analysis of the chemorheological behavior of an epoxy prepolymer based on a diglycidylether of bisphenol‐A (DGEBA) with a liquid aromatic diamine (DETDA 80) as a hardener was performed by combining the data obtained from Differential Scanning Calorimetry (DSC) with rheological measurements. The kinetics of the crosslinking reaction was analyzed at conventional injection temperatures varying from 100 to 150°C as experienced during a Resin Transfer Molding (RTM) process. A phenomenological kinetic model able to describe the cure behavior of the DGEBA/DETDA 80 system during processing is proposed. Rheological properties of this low reactive epoxy system were also measured to follow the cure evolution at the same temperatures as the mold‐filling process. An empirical model correlating the resin viscosity with temperature and the extent of reaction was obtained to carry out later a simulation of the RTM process and to prepare advanced composites. Predictions of the viscosity changes were found to be in good agreement with the experimental data at low extents of cure, i.e., in the period of time required for the mold‐filling stage in RTM process. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4228–4237, 2006
Synthesis of the copolymer hydrogel κ‐carrageenan‐graft‐PAAm: Evaluation of its absorbent and adhesive properties
Authors: Meena Ramavatar , Prasad Kamalesh , Mehta Gaurav , Siddhanta A. K. 
Published: September 2006

Abstractκ‐Carrageenan‐graft‐PAAm, a copolymer hydrogel of κ‐carrageenan (kC) and acrylamide (AAm), has been synthesized in aqueous medium at ∼ pH 7 in the presence of the initiator potassium persulfate (KPS), using microwave irradiation. The reaction conditions were optimized by varying the concentration of AAm and KPS to obtain copolymer hydrogels having different nitrogen contents e.g., %N 6.35, 10.56, and 11.05. It was observed that copolymer hydrogel having %N 11.05 gives superior adhesive properties whereas copolymer hydrogel with %N 10.56 produces superior absorbent properties in the presence of optimized concentrations of AAm (0.87 and 1.1428 mol/L respectively) and KPS (0.022 and 0.0296 mol/L respectively). The product with %N 6.35 is a soft gel (2–5% gel in 1% KCl) exhibiting low gel strength (135 g cm−2). The one with %N 10.56 showed superior swelling property and maximum swelling was observed in the alkaline pH (22 g/g). The swelling behaviors of the hydrogels were studied at different pHs (pH 1.2–12.5) as well as in 1% aqueous solutions of NaCl, KCl, and CaCl2. The 5% dispersion of the hydrogel having %N 11.05 in water had good binding properties with papers, polyethylene sheets, and wood pieces. To evaluate the measure of adhesive property, the viscosity and solid and liquid weights of the applied adhesive were measured. Characterization of the copolymer hydrogels was done by TGA, X‐ray diffraction, 13C‐NMR, FT‐IR, elemental analyses, and rheological studies. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5144–5152, 2006
Preparation and characterization of acrylic resin/titania hybrid nanocomposite coatings by photopolymerization and sol–gel process
Authors: Sangermano M. , Amerio E. , Priola A. , Di Gianni A. , Voit B. 
Published: September 2006

AbstractTitania‐containing coatings were prepared through a dual‐cure process involving radical photopolymerization of a polysiloxane diacrylate and subsequent condensation of alkyltitanate groups. The kinetics of photopolymerization and condensation reaction was investigated as a function of the inorganic phase precursor (titanium tetraisopropoxide) content. AFM analysis gave evidence of a strong interaction between the organic and inorganic phase with the formation of titania domains in the nanoscale region. An increase of hydrophilicity in the coatings surface with increasing TiO2 content was evidenced. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4659–4664, 2006
Development of conductive cotton fabrics for heating devices
Authors: Bhat Narendra V. , Seshadri Devender T. , Nate Mandar M. , Gore Ajit V. 
Published: September 2006

AbstractRecent developments in the area of textiles to make fabrics more functional have led to synthesizing “intelligent fabrics.” This can be achieved by making the fabrics electrically conducting. In the present study it is reported that the cotton fabrics, when impregnated with polypyrrole, achieve enhanced level of conduction. The method of diffusion of pyrrole, followed by polymerization using iron chloride as oxidant, was used. The different levels of conduction were achieved by varying the contents of monomer in the bath from 0.01 to 0.1M during the synthesis. The conductivity could be enhanced from the initial value of 10−12 to 101 S/cm. It is shown that when a fixed voltage is applied to such a modified piece of cloth, the heat generated is up to 1000 W/m2 depending on the percentage of pyrrole present. Such fabrics can be used as heating pads and integrated into the apparel to keep the wearer warm enough using a portable 9.0‐V battery. Being flexible and breathable, such fabrics have better comfort properties (compared with conventional heating pads). It can find applications in dresses for army personnel and old‐age patients. Such conductive fabrics can also find applications in many areas such as electromagnetic interference shielding, gas sensors, and temperature indicators. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4690–4695, 2006
Thermal stability and degradation studies of alternating poly(ester amide)s derived from glycolic acid and ω‐amino acids
Authors: Botines E. , Franco L. , Puiggalí J. 
Published: September 2006

AbstractThe thermal degradation of three poly(ester amide)s derived from glycolic acid and different ω‐amino acids is studied by thermogravimetric analysis (TGA) at different heating rates and the results are compared. Thermal decomposition follows a two‐step reaction, the mechanism involved in each step being possible to be determined. Nonisothermal integral isoconversional methods (such as Kissinger, KAS, and Flynn–Wall–Ozawa) and linear equations and differential methods (such as the Friedman expression) were used to obtain the kinetic parameters from TGA and DTGA curves. The complete kinetic triplets are also determined by the Coats–Redfern and the invariant kinetic parameters methodologies. Hydrolytic and enzymatic degradation studies, where weight losses, intrinsic viscosity changes and NMR spectra of degraded samples are evaluated, are also undertaken. The polymers seem interesting because of their application as new biodegradable materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5545–5558, 2006
Effects of polyhedral oligomeric silsesquioxane coatings on the interface and impact properties of carbon‐fiber/polyarylacetylene composites
Authors: Zhang Xuezhong , Huang Yudong , Wang Tianyu , Liu Li 
Published: September 2006

AbstractTwo kinds of polyhedral oligomeric silsesquioxane (POSS) coatings were used for the modification of the interface in carbon fiber (CF) reinforced polyarylacetylene (PAA) matrix composites. The effects of the organic–inorganic hybrid POSS coatings on the properties of the composites were studied with short‐beam‐bending, microdebonding, and impact tests. The interlaminar shear strength and interfacial shear strength showed that the POSS coatings resulted in an interfacial property improvement for the CF/PAA composites in comparison with the untreated ones. The impact‐test results implied that the impact properties of the POSS‐coating‐treated composites were improved. The stiffness of the interface created by the POSS coatings was larger than that of the fiber and matrix in the CF/PAA composites according to the force‐modulation‐mode atomic force microscopy test results. The rigid POSS interlayer in the composites enhanced the interfacial mechanical properties with a simultaneous improvement of the impact properties; this was an interesting phenomenon in the composite‐interface modification. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5202–5211, 2006
UV‐curable methacrylic epoxy dispersions for cationic electrodeposition coating
Authors: Kim Y. B. , Kim H. K. , Hong J. W. 
Published: September 2006

AbstractUV‐curable epoxy dispersions were prepared for cationic electrodeposition coating. Sequential reactions were used to introduce methacrylate groups to the epoxy‐amine polymer as coupling agents to the multifunctional acrylates. The molecular weight values of the prepared epoxy‐amine polymer were Mn = 2800 and Mw = 4300. The neutralized epoxy‐amine polymer containing photoinitiator with or without multifunctional acrylate (pentaerythritol triacrylate, PETA) could be dispersed into a stable dispersion without any phase separation. The size of the particles in these epoxy dispersions was approximately 77.7 nm, and increased with the incorporation of PETA. The electrodeposition process was introduced to the prepared epoxy dispersions, and the electrodeposited films were cured by UV irradiation after a 10‐min flash off at 80°C. Studies of the kinetics using photo‐DSC revealed that the crosslinked films containing PETA gave a higher conversion rate than those without PETA, resulting in better resistance to methyl ethyl ketone. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5566–5570, 2006
Effects of carbon nanotube fillers on the curing processes of epoxy resin‐based composites
Authors: Tao Kun , Yang Shuying , Grunlan Jaime C. , Kim Yeon‐Seok , Dang Bachlien , Deng Yuanjian , Thomas Renard L. , Wilson Bobby L. , Wei Xin 
Published: September 2006

AbstractThe effects of different grades of carbon nanotubes on the curing of a typical epoxy resin (EPIKOTE™ resin 862 and EPIKURE™ curing agent W) were examined via differential scanning calorimetry. It was found that nanotubes could initiate cure at lower temperatures, while the overall curing process was slowed as evidenced by lower total heat of reaction and lower glass transition temperatures of the cured nanocomposites compared to neat epoxy. This finding is practically important as it is essential to have a consistent degree of cure when the properties of thermosets with nanoinclusions are compared to neat resins. It was also found that the inclusion of carbon nanotubes might induce the thermal degradation of epoxy composites at lower temperatures. Morphological analysis done with scanning electron microscopy revealed good dispersion of nanotubes within the epoxy matrix. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5248–5254, 2006
Wetting properties of human hair by means of dynamic contact angle measurement
Authors: Lodge Richard A. , Bhushan Bharat 
Published: September 2006

AbstractThe interaction between human hair and water occurs continuously in atmospheric air, and even more so, during application of shampoo and conditioner. For this reason the wettability of hair, and how hair care products affect the wetting properties, is of interest to hair care science. In this study, the Wilhelmy balance method is used to measure dynamic contact angle of both conditioner‐treated hairs and those left untreated to study the interaction of hair with water. The method uses a microbalance to measure the force exerted on a single fiber when it is immersed into the wetting liquid of interest. This measured force is related to the wetting force of the liquid on the fiber, and the dynamic contact angle can be calculated. The contact angles of chemically damaged, mechanically damaged, virgin (undamaged) as well as conditioner‐treated hairs and those left untreated are measured and compared. These samples were measured dry, and then also allowed to soak in water before being measured to determine whether a wet environment affects the wetting properties of the hair surface. Additionally, wettability of hairs from subjects of different ethnicities are measured and compared. Further, the mechanisms driving a significant directionality dependence are studied and discussed. The results are also used to explain tribological properties found in previous studies. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5255–5265, 2006
Structure and mechanical properties of thermoplastic polyurethane, based on hyperbranched polyesters
Authors: Cao Qi , Cai Yuanli , Jing Bo , Liu Pengsheng 
Published: September 2006

AbstractA series of hyperbranched polyurethane (HB‐PU) were synthesized using hyperbranched polyester as a precursor. Morphology of these HB‐PU films was investigated using atomic force microscopy and wide‐angle X‐ray diffraction; it's molecular dynamics was studied by dynamic mechanical analysis. FTIR studies showed that hard segments get more aggregated to form domains in the HB‐PU block copolymer as hard segment content increases. Such domain formation has a significant influence on the mechanical and thermomechanical properties of HB‐PU, such as maximum stress and elongation at break. Especially, maximum stress and elongation at break increased significantly at 25 wt % of hard segment content, and the highest loss tangent was observed at the same composition. Heat of crystallization as measured by differential scanning calorimetry is also dependent on the hard segment content, and the control of hard segment content in PU block copolymers is very important in determining their physical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5266–5273, 2006