bluuebunny/crossref_metadata_2025 huggingface dataset:
Coupling between homogeneous rate processes and fluid deformation rate: Brownian particle coagulation in a rapidly dilating solvent
Authors: Rosner Daniel E. , Arias‐Zugasti Manuel
Published: April 2010

P. Curie's principle applied to an isotropic medium of arbitrary EOS does not preclude coupling between homogeneous (chemical,…) rate processes and local fluid dilation rate. Yet, practical examples of this coupling have largely remained unexplored. Using recently studied supercritical “antisolvent” (SAS) examples for precipitating high‐value particles (e.g., pharmaceuticals), we suggest that the characteristic dilation time tV of the swelling solvent can be small enough to noticeably reduce the operative coagulation rate “constant,” β. Moreover, we expect that this coupling can occur under conditions in which postnucleation Brownian coagulation must be accounted for in predicting the efficacy of such micron‐sized powder production methods. Accordingly, a rational approximate theory for this rate constant “correction factor,” β/β(0), is proposed here, emphasizing the applicable limit of continuum Brownian diffusion control. We also present a preliminary assessment of the particle size distribution (PSD) consequences of these “corrections,” implying strategies to reduce both mean particle size and PSD spread. Possible generalizations are indicated. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Bortezomib plus intermediate‐dose dexamethasone and thalidomide in elderly untreated patients with multiple myeloma: A Chinese experience
Authors: Guo Hongfeng , Zhou Xin , Jiang Yuanqiang , Yang Guohua , Sun Chao , Zhuang Yun , Sun Hongli , Lu Mize , Qian Xifeng , Chen Feng , Mao Jingjue , Chen Heng , Xia Jun , Shen Yunfeng
Published: April 2010

Bortezomib has proven to be active in patients with multiple myeloma (MM), including elderly patients. The aim of this study was to evaluate the efficacy and toxicity of bortezomib in combination with intermediate‐dose dexamethasone (Dex) and thalidomide in untreated MM patients aged ≥65 years in a Chinese single center. In this study, 18 patients were treated with bortezomib at 1.3 mg/m2 IV on Days 1, 4, 8, and 11 and Dex at 20 mg/day IV on Days 1–4 and 8–11 simultaneously. Thalidomide at dose of 100 mg/day was given everyday. The mean number of cycles of bortezomib treatment was 2.06. Three patients (17%) achieved a complete response (CR), four (22%) a very good partial response (VGPR), and nine (50%) a PR, resulting in an overall response rate of 89%. The median time to response was 22 days (range 14–50 days). The duration of response was significantly longer in patients achieving a CR/VGPR with respect to those achieving only a PR (8.5 vs. 4.2 months, P = 0.03). Grade 3–4 toxicities occurring in patients comprised weakness, thrombocytopenia, diarrhea, infection, and neuropathy. Only one patient suffered from deep vein thrombosis. This preliminary experience in Chinese patients indicated that bortezomib‐Dex‐thalidomide is highly effective in elderly untreated patients with MM, even in patients with poor prognostic features. Am. J. Hematol. 2010. © 2010 Wiley‐Liss, Inc.
Genetic characterization of uniparental lineages in populations from Southwest Iberia with past malaria endemicity
Authors: Pereira Vânia , Gomes Verónica , Amorim António , Gusmão Leonor , João Prata Maria
Published: April 2010

Malaria endemicity in Southwest Iberia afforded conditions for an increase of sickle cell disease (SCD), which in the region follows a clinal pattern toward the south, where foci of high prevalence were found. SCD distribution is associated with specific geographical areas, and therefore, its introduction into Iberia may be related to the migration of different populations. We have analyzed the variation of uniparental markers in Portuguese populations with high frequency of SCD—Coruche, Pias, and Alcacer do Sal—to evaluate if their present‐day pattern of neutral diversity could provide evidence about people inhabiting the area over different time periods. Two hundred and eighty‐five individuals were sampled in Coruche, Pias, and Alcacer do Sal. All were analyzed for the control region of mitochondrial DNA (mtDNA); males were additionally examined for Y‐chromosome markers. Results were then compared with data from other Portuguese and non‐Portuguese populations. In Coruche, the genetic profile was similar to the profile usually found in Portugal. In Alcacer do Sal, the frequency of sub‐Saharan mtDNA L lineages was the highest ever reported (22%) in Europe. In Pias, mtDNA diversity revealed higher frequencies of Mediterranean haplogroups I, J, and T than usually found in surrounding populations. The presence of Sub‐Saharan maternal lineages in Alcacer do Sal is likely associated with the influx of African slaves between the 15th and 19th centuries, whereas in Pias, the Mediterranean influence might be traced to ancient contacts with Greeks, Phoenicians, and Carthaginians, who established important trading networks in southern Iberia. Am. J. Hum. Biol. 22:588–595, 2010. © 2010 Wiley‐Liss, Inc.
Relationships between adiponectin, leptin, and blood lipids in physically active postmenopausal females
Authors: Jürimäe Toivo , Jürimäe Jaak , Leppik Aire , Tafeit Erwin , Kums Tatjana
Published: April 2010

The aim of this study was to investigate the possible relationships between adiponectin and leptin with blood lipids (CHOL, HDL‐C, LDL‐C, and TG) in physically active postmenopausal women. One hundred and thirty‐four physically active practicing gymnastics (2–3 times per week) women between the ages of 51 to 85 years participated in this cross‐sectional study. Body height, body mass, waist‐to‐hip circumference ratio (WHR), and BMI were used as anthropometrical parameters. Body composition parameters (fat%, fat mass, fat free mass) were measured by DXA. The fasting adiponectin, leptin, CHOL, HDL‐C, LDL‐C, and TG were measured. From the anthropometrical and body composition parameters, only WHR correlated significantly with adiponectin (r = −0.306). In addition, adiponectin correlated with TG (r = −0.277) and leptin (r = −0.381). Leptin was positively related to body mass (r = 0.261), and BMI (r = 0.274) from anthropometrical parameters and body fat% (r = 0.288) and fat mass (r = 0.298) from body composition variables. No relationships emerged between leptin and blood lipids. We found that there are some significant relationships between adiponectin, leptin and anthropometrical and body composition parameters in physically active postmenopausal females. From blood lipids, only TG correlated significantly with adiponectin. Am. J. Hum. Biol. 22:609–612, 2010. © 2010 Wiley‐Liss, Inc.
Polygenic inheritance of adolescent idiopathic scoliosis: A study of extended families in Utah
Authors: Ward Kenneth , Ogilvie James , Argyle VeeAnn , Nelson Lesa , Meade Mary , Braun John , Chettier Rakesh
Published: April 2010

A heritability study of 69 extended Utah families with a history of adolescent idiopathic scoliosis (AIS) indicates that AIS is a polygenic, multifactorial condition. Each family reported a history of AIS within four generations; a total of 247 individuals were confirmed via X‐rays and medical records to have AIS. Coefficient of kinship was more than 25 standard deviations higher for these 69 families than for the general population. Excluding all probands and assuming autosomal dominant inheritance, 1,260 individuals over the age of 16 were determined to be at risk for AIS because they have a parent with AIS. Assuming 50% of these individuals carry the allele, estimated penetrance in at‐risk males is approximately 9%, and estimated penetrance in at‐risk females is approximately 29%. Recurrence risk in relatives decreases as the degree of relationship to the affected individual becomes more distant; however, the lowest recurrence risk calculated, for third‐degree relatives, is still an average of 9%, well above the general population's risk. Onset of AIS appears to be inherited separate from curve pattern and severity. In a study of phenotypes in 36 of the families, the affected individuals were consistent in either curve severity or curve pattern, but not both. It is unclear whether severity or pattern is more heritable, but it is possible that the location of the curve on the spine is the most heritable trait of the phenotype. The study demonstrates the genetic complexity of AIS, including the low penetrance of its cumulative alleles and variable expression. © 2010 Wiley‐Liss, Inc.
Immunohistochemistry in non‐immune hydrops fetalis: A single center experience in 79 fetuses
Authors: Bellini Carlo , Fulcheri Ezio , Rutigliani Mariangela , Calevo Maria Grazia , Boccardo Francesco , Campisi Corradino , Bonioli Eugenio , Bellini Tommaso , Hennekam Raoul C.M.
Published: April 2010

The objective of our study was to evaluate the usefulness of immunohistochemical (IHC) staining techniques in the etiological diagnosis of non‐immune hydrops fetalis (NIHF). The records of all 1,098 autopsies performed between January 1987 and May 2008, by the Division of Fetal Pathology of the University of Genoa, were reviewed and all 79 fetuses diagnosed with NIHF were re‐evaluated. Additional IHC staining using antibodies that specifically stain blood and lymph vessels (CD31, CD34, smooth muscle actin antibody, D2‐40) were performed. Results were compared to results from the literature. Our results showed that in 67/79 cases, evaluation by standard autopsy protocol led to an etiologic diagnosis. Furthermore, we were able to identify the pathogenetic mechanisms that eventually caused NIHF in 42/79 cases. Adding IHC staining to all evaluations identified the pathogenetic mechanism in a further 17 cases (total 59/79 cases). Lymphatic dysplasia was diagnosed by standard autopsy protocol in 1/79 (1.3%), while adding IHC staining resulted in 18/79 (22.8%) cases being diagnosed (P = 0.0001). The present rate of 22.8% of lymphatic dysplasia in non‐immune hydrops fetalis is significantly higher than reported in the literature (36/818 or 4.4%; P = 0.01). In conclusion, specific IHC staining techniques aimed at detecting lymphatic dysplasia are needed and should be mandatory in autopsies of fetuses with non‐immune hydrops fetalis. © 2010 Wiley‐Liss, Inc.
A homozygous deletion of 8q24.3 including the NIBP gene associated with severe developmental delay, dysgenesis of the corpus callosum, and dysmorphic facial features
Authors: Koifman Arie , Feigenbaum Annette , Bi Weimin , Shaffer Lisa G. , Rosenfeld Jill , Blaser Susan , Chitayat David
Published: April 2010

We have identified by microarray‐based comparative genomic hybridization analysis (aCGH), a homozygous deletion of 8q24.3 [arr cgh 8q24.3(140,879,937 → 141,021,392)x0 mat pat] in a patient with dysmorphic facial features, dysgenesis of the corpus callosum, and severe mental retardation. The deletion was inherited from asymptomatic, consanguineous parents, each of them being heterozygous for the same deletion. The only gene known to map to this segment is the NIBP gene, and so far no clinical manifestations have been found in association with this gene mutation in homozygous or heterozygous state in humans. Our findings suggest that a homozygous deletion in the NIBP gene results in an autosomal recessive condition with multiple abnormalities and severe delay. In addition, the child inherited a 781‐kb deletion on 4q32.2 from the mother that contains the SPOCK3 gene. We suggest that this heterozygous deletion is likely to be non‐contributory to the phenotype. © 2010 Wiley‐Liss, Inc.
Increased number of sex chromosomes affects height in a nonlinear fashion: A study of 305 patients with sex chromosome aneuploidy
Authors: Ottesen Anne Marie , Aksglaede Lise , Garn Inger , Tartaglia Nicole , Tassone Flora , Gravholt Claus H. , Bojesen Anders , Sørensen Kaspar , Jørgensen Niels , Rajpert‐De Meyts Ewa , Gerdes Tommy , Lind Anne‐Marie , Kjaergaard Susanne , Juul Anders
Published: April 2010

Tall stature and eunuchoid body proportions characterize patients with 47,XXY Klinefelter syndrome, whereas patients with 45,X Turner syndrome are characterized by impaired growth. Growth is relatively well characterized in these two syndromes, while few studies describe the growth of patients with higher grade sex chromosome aneuploidies. It has been proposed that tall stature in sex chromosome aneuploidy is related to an overexpression of SHOX, although the copy number of SHOX has not been evaluated in previous studies. Our aims were therefore: (1) to assess stature in 305 patients with sex chromosome aneuploidy and (2) to determine the number of SHOX copies in a subgroup of these patients (n = 255) these patients and 74 healthy controls. Median height standard deviation scores in 46,XX males (n = 6) were −1.2 (−2.8 to 0.3), +0.9 (−2.2 to +4.6) in 47,XXY (n = 129), +1.3 (−1.8 to +4.9) in 47,XYY (n = 44), +1.1 (−1.9 to +3.4) in 48,XXYY (n = 45), +1.8 (−2.0 to +3.2) in 48,XXXY (n = 9), and −1.8 (−4.2 to −0.1) in 49,XXXXY (n = 10). Median height standard deviation scores in patients with 45,X (n = 6) were −2.6 (−4.1 to −1.6), +0.7 (−0.9 to +3.2) in 47,XXX (n = 40), −0.6 (−1.9 to +2.1) in 48,XXXX (n = 13), and −1.0 (−3.5 to −0.8) in 49,XXXXX (n = 3). Height increased with an increasing number of extra X or Y chromosomes, except in males with five, and in females with four or five sex chromosomes, consistent with a nonlinear effect on height. © 2010 Wiley‐Liss, Inc.
Hereditary multiple exostoses with spine involvement in a 4‐year‐old boy
Authors: Ezra Navid , Tetteh Beatrice , Diament Michael , Jonas Adam J. , Dickson Patricia
Published: April 2010

Hereditary multiple exostosis (HME) is an autosomal dominant disorder characterized by multiple osteochondromas. We describe a case of acute cervical spinal cord compression arising from an exostosis at the lamina of C7 and T1 in a 4‐year‐old Mexican‐American boy with HME. His affected sibling also displayed spinal cord compression because of a bony exostosis. Acute cervical spinal cord compression resulting from osteochondroma is a serious complication of HME. © 2010 Wiley‐Liss, Inc.
FMR1 gene expansion, large deletion of Xp, and skewed X‐inactivation in a girl with mental retardation and autism
Authors: Vazna Alzbeta , Musova Zuzana , Vlckova Marketa , Novotna Dhahuse , Dvorakova Lenka , Hrdlicka Michal , Havlovicova Marketa , Sedlacek Zdenek
Published: April 2010

We describe a girl with mild facial anomalies, mild mental retardation, and atypical autism with a remarkable behavioral phenotype of persistent anger, aggression, and dysphoria. The occurrence of late‐onset tremor and premature ovarian failure in the maternal branch of the family pointed to a possible defect in the FMR1 gene. Indeed, the patient carried a full FMR1 mutation. Unexpectedly, both alleles of the gene were almost completely methylated. Cytogenetic examination of the patient revealed in addition a large de novo deletion in band Xp22 on one of her X chromosomes. The deletion was fine mapped using oligonucleotide array CGH, and its breakpoints were localized using sequencing. The size of the deletion was about 17.4 Mb, and it contained more than 90 protein‐coding genes. Microsatellite analysis indicated paternal origin of the aberrant chromosome. The large rearrangement was the most probable cause of the X‐inactivation skewing, thus explaining the methylation of not only the expanded (maternal) but also the normal (paternal) FMR1 alleles. This pattern of skewed X‐inactivation was confirmed using the analysis of methylation at the AR locus. The relatively mild phenotype of the patient resulted most likely from unmasking of the FMR1 defect. Although the deleted region contained many important genes, the phenotypic contribution of the rearranged X chromosome was probably limited by its almost complete inactivation. However, reduced dose of several genes escaping X‐inactivation might also play a role in the phenotype of the patient. © 2010 Wiley‐Liss, Inc.
Left ventricular non‐compaction on MRI in a patient with 22q11.2 distal deletion
Authors: Madan Shobhit , Madan‐Khetarpal Suneeta , Park Sang C. , Surti Urvashi , Bailey Ariel L. , McConnell Juliann , Tadros Sameh S.
Published: April 2010

We report on a 22‐year‐old male carrying a presumptive clinical diagnosis of Dubowitz‐like phenotype who has been followed‐up by cardiology for bicuspid aortic valve with ascending aorta and aortic root dilatation. Cardiac magnetic resonance imaging (CMRI) confirmed these findings, along with an incidental finding of left ventricular non‐compaction (LVNC). Genetic workup revealed the diagnosis of 22q11.2 distal deletion encompassing the BCR gene. This is the first time LVNC has been reported in a patient with 22q11.2 distal deletion. © 2010 Wiley‐Liss, Inc.
Premature ovarian failure, absence of pubic and axillary hair with de novo 46,X,t(X;15)(q24;q26.3)
Authors: Giacomozzi Claudio , Gullotta Francesca , Federico Giovanni , Colapietro Isabella , Nardone Anna Maria , Cianfarani Stefano
Published: April 2010

We report on an adolescent girl with premature ovarian failure (POF), de novo unbalanced translocation X;15(q24;q26.3) with partial Xq24 duplication, and absence of pubic and axillary hair. Endocrine assessment showed normal adrenal and ovarian function. Chromosomal abnormality was identified by standard cytogenetic methods, array‐CGH, and FISH analysis. Mutation analysis showed normal androgen receptor genes. Pubic and axillary hair began developing during estrogen + progesterone therapy. Our patient demonstrates that a distal X‐breakpoint involving POF1 locus is able to cause POF without virilization during adolescence. © 2010 Wiley‐Liss, Inc.
Haploinsufficiencies of FOXF1 and FOXC2 genes associated with lethal alveolar capillary dysplasia and congenital heart disease
Authors: Yu Shihui , Shao Lei , Kilbride Howard , Zwick David L.
Published: April 2010

Neonatal deaths account for about 67% of all deaths during the first year of life in the USA. Genetic defects are important factors contributing to neonatal deaths and congenital anomalies. Here we report on the identification of a 1.37 Mb de novo deletion of chromosome 16q24.1‐q24.2 by microarray‐based comparative genomic hybridization (aCGH) technique in a newborn boy with lethal severe alveolar capillary dysplasia and multiple congenital anomalies who died of irreversible pulmonary hypertension, respiratory failure and cor pulmonale at three days of age. The phenotypic findings and causal genes (FOXF1 and FOXC2) involved in producing this unusual syndrome are detailed. Our findings independently confirm the results in a previous publication describing multiple patients with similar clinical and genetic observations, and highlight the importance of scanning human genomes at high resolution for identifications of micro‐imbalances as pathogenic causes in neonates with unexplained congenital anomalies. © 2010 Wiley‐Liss, Inc.
Copper‐catalyzed asymmetric 1,4‐conjugate addition of dialkylzinc to enones
Authors: Gou Shaohua , Ye Zhongbin , Shi Leiting , Qing Dayong , Zhang Wen , Wang Yuliang
Published: April 2010

Asymmetric 1,4‐conjugation addition of dialkylzinc (diethylzinc and dimethylzinc) to cyclic enones, chalcone and nitroalkenes was achieved by a 25 mol% (R)‐6,6′‐Br2‐BINOL(1f), 25 mol% CuSPh and 100 mol% dicyclohexylmethylamin(Cy2NMe) catalyst system. The Cu(I) catalyst system enables the cyclic enone, chalcone and nitroalkene generality with high enantioselectivity (up to 84% ee) and isolated yield (up to 94%) under mild reaction conditions. Copyright © 2010 John Wiley & Sons, Ltd.
Optimized surface silylation of chemically amplified epoxidized photoresists for micromachining applications
Authors: Kontziampasis D. , Beltsios K. , Tegou E. , Argitis P. , Gogolides E.
Published: April 2010

We explored the selective wet silylation of noncrosslinked areas of epoxidized photoresists using chlorosilanes. Emphasis was placed on the Si uptake of the epoxy films when controlled low levels of water were incorporated into the silylation solution. Fourier transform infrared measurements and oxygen‐plasma resistance data with in situ laser interferometry and multiwavelength ellipsometry are presented. The fine tuning of the moisture level was found to be crucial for the generation of satisfactory and reproducible structures. The optimized version of the process was shown to be useful for epoxy‐based dry micromachining. Overall, an attractive positive‐tone process is presented as an alternative to the usual negative‐tone process for commercial epoxy resists. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of the shape of dispersed particles on the thermal and mechanical properties of biomass polymer blends composed of poly(L‐lactide) and poly(butylene succinate)
Authors: Yokohara Tadashi , Okamoto Kenzo , Yamaguchi Masayuki
Published: April 2010

The structure and properties of binary blends composed of poly(lactic acid) (PLA) and fibrous poly(butylene succinate) (PBS), which were prepared by an uniaxial stretching operation in the molten state, were studied and compared with those of blends having spherical particles of PBS in a continuous PLA phase. We found from electron microscope observation that PBS nanofibers with a large aspect ratio were generated in the stretched samples. Enlargement of the surface area of the PBS particles, which showed nucleating ability for PLA, led to a high degree of crystallization and enhanced the cold crystallization in the heating process. Moreover, the PBS fibers in the stretched samples had a dominant effect on the mechanical properties in the point range between the glass‐transition temperature of PLA and the melting temperature of PBS. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A design of experiments (DoE) approach to material properties optimization of electrospun nanofibers
Authors: Coles Stuart R. , Jacobs Daniel K. , Meredith James O. , Barker Guy , Clark Andrew J. , Kirwan Kerry , Stanger Jon , Tucker Nick
Published: April 2010

Using an electrospinning technique, polymer materials have been spun using electrostatic potential to create a fiber mat. To develop the electrospinning opportunities available for practical applications, it is important that a full understanding of process parameters is achieved. These fundamental principles will form the initial framework of future research with the effects on polymer output examined as the primary focus of this article. Poly(vinyl alcohol) (PVOH) and polylactic acid (PLA) polymer solutions were developed and a Design of Experiments (DoE) approach implemented, to determine whether the variation of factors led to significant effects on fiber output. Parameters altered were conductivity, concentration (% w/w), electrostatic potential, and the collection distance at which the fiber was obtained. Results taken considered the fiber diameter, deposition rate of material, current achieved at the point of collection and whether or not the material was actually able to electrospin and visibly produce polymer fiber. The results of this work indicate the presence of interactions between the processing parameters and as such allow a fine tuning process to be used to adapt production of the micro‐ and nanofibers to suit a desired application with specific materials properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Novel Zr(IV)/sugar beet pulp composite for removal of sulfate and nitrate anions
Authors: Hassan Mohammad L. , Kassem Nesrine F. , Abd El‐Kader Amal H.
Published: April 2010

A new inorganic/sugar beet pulp composite that can be used as anion exchanger material was prepared from sugar beet pulp (SBP) after loading with zirconium (IV) ions. The prepared anion exchanger material was examined for its ability to remove sulfate and nitrate anions from water. The effect of contact time, anions concentration, temperature, and pH on the adsorption capacity of Zr(IV)‐loaded SBP was studied. The maximum adsorption capacity of Zr(IV)‐loaded SBP was about 114 mg/g and 63 mg/g for sulfate and nitrate, respectively. In addition, the effect of the regeneration of the Zr‐loaded SBP after anion removal has been studied. The results of anions adsorption test and EDX‐SEM showed that zirconium ions are strongly bound to the carboxylate groups of SBP constituents, especially pectins, and are not leached as a result of regeneration. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Polymer‐insulating material for rated electrical applications
Authors: Maiti Pravat Kumar
Published: April 2010

Putty is an encapsulation polymer‐insulating material that protects the windings of large motors, generators, and transformers from coronas, radiation, and heat. It is used as a barrier insulation in windings to make void‐free and air‐gap‐free structures. A two‐pack epoxy putty has been developed with inorganic‐filler powder materials. The cured putty system has very high adhesion to substrates, and it is flexible enough to absorb the heating and cooling cycles of coils without cracking after long‐time use. The mechanical and electrical properties of the putty have been determined with methods of the American Society for Testing and Materials. The temperature class of the putty is 203°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Waste pine cones as a source of reinforcing fillers for thermoplastic composites
Authors: Ayrilmis Nadir , Buyuksari Umit , Dundar Turker
Published: April 2010

In this study, we evaluated some physical and mechanical properties of polypropylene (PP) composites reinforced with pine‐cone flour and wood flour. Five types of wood–plastic composites (WPCs) were prepared from mixtures of cone flour, wood flour, PP, and a coupling agent. The water resistance and flexural properties of the composites were negatively affected by an increase in cone‐flour content. Extractives in the cone flour had a significant effect on the flexural properties of the WPCs. However, the flexural properties and water resistance of the WPC samples were not significantly affected by the addition of 10 wt % of the cone flour when compared to the WPC samples made from wood flour. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Simultaneous estimation of the phase content and lamellar thickness in isotactic polypropylene by the simulated annealing of wide‐angle X‐ray scattering data
Authors: Subramanian Gopinath , Ozisik Rahmi
Published: April 2010

Wide‐angle X‐ray scattering (WAXS) patterns of isotactic polypropylene (iPP) were analyzed in terms of the ideal WAXS patterns of their individual phases. Analysis was done with the technique of simulated annealing. This analysis is a novel method for simultaneously obtaining the volume fractions of the crystalline and amorphous phases and the average lamellar thickness of the individual crystalline phases. The method is different from traditional methods as it allowed us to obtain a large amount of information in a single step from a single WAXS pattern. This study was limited to a few selected specimens of iPP, but the method expounded could, in principle, be extended to other polymers and polymer blends. The limits of its applicability and possible shortcomings are discussed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Studies on the effect of epoxide equivalent weight of epoxy resins on thermal, mechanical, and chemical characteristics of vinyl ester resins
Authors: Pal Neelam , Srivastava Deepak , Rai J. S. P.
Published: April 2010

Three samples of vinyl ester resins (VERs) were synthesized using bisphenol‐A‐based epoxy resins of varying epoxide equivalent weights (EEW) and acrylic acid in presence of triphenylphosphine as a catalyst at 80 ± 2°C. The cresyl glycidyl ether was used as reactive diluent during the synthesis of VERs. A suitable reaction mechanism was proposed and discussed for the reactions involving epoxide group and acid groups. This was further confirmed by infrared spectroscopic analysis. The maximum peak temperature from DSC were at 106.05°C, 114.20°C, and 128.86°C for benzoyl peroxide initiated VERs viz. samples V1CV, V2CV, and V3CV, respectively, increased with the increase of EEW of the parent epoxy resin. It has also been found that the films of VER having highest EEW of bisphenol‐A epoxy resin showed best chemical resistance amongst all other VERs in this study. The mechanical properties such as hardness and flexibility also showed a similar trend. The thermal stability was found to decrease with the increase of EEW of bisphenol‐A epoxy resin in the VERs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Isothermal crystallization and melting behavior of 2‐methyl‐1,3‐propanediol substituted sulfonated poly(ethylene terephthalate) copolyesters
Authors: Chen Bin , Gu Lixia
Published: April 2010

Poly(ethylene terephthalate) copolyesters (abbreviated as MCDP) containing 2‐methyl‐1,3‐propanediol (MPD) and sodium‐5‐sulfo‐bis‐(hydroxyethyl)‐isophthalate (SIP) units were synthesized through a direct polycondensation reaction. Chemical compositions of the copolyesters were determined by 1H‐ and 13C‐ NMR spectroscopy, respectively. Thermal properties and isothermal crystallization behavior were characterized using DSC analysis. Results exhibited that the crystallization rate of MCDP copolyesters was depressed with increasing MPD content. The equilibrium melting temperature of MCDP copolyesters showed a marked decrease when the composition of MPD increased, indicating the incorporation of MPD units lead to less perfect crystals. The crystal structure was investigated via using WAXD patterns. It was confirmed that MPD and SIP can not enter into the crystal region. The crystal morphology observed by using POM clearly showed that the presence of MPD units depressed the crystallization ability of MCDP copolyesters. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of talc content on some properties of gamma irradiated composites of polyethylene and recycled rubber wastes
Authors: Hassan Medhat M. , Aly Raouf O. , Hasanen Jehan A. , El Sayed El Sayed F.
Published: April 2010

In this study, the synergistic effect of talc content % and gamma irradiation on some mechanical, thermal, electrical resistance, and microstructural properties of the molded waste polyethylene/recycled waste rubber powder (WPE/RWRP) 60/40 was investigated. The ternary composites of talc concentrations, 5, 10, 15, and 20 wt %, were irradiated with doses of 50, 75, 100, and 150 kGy. The composites mechanical properties: tensile strength, elongation at break, and elasticity modulus, and the thermal properties: melting temperature (Tm) and (ΔH) were predicted. Also, scanning electron microscopy, thermogravimetric analysis, and electric conductivity were investigated. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Rheological properties of methylcellulose aqueous gels under dynamic compression: Frequency sweep and validity of scaling law
Authors: Kundu Madhumita , Mallapragada S. , Larock R. C. , Kundu P. P.
Published: April 2010

The aqueous methylcellulose (MC) gels are characterized with a dynamic mechanical analyzer (DMA) under dynamic vertical compression. During the frequency sweeps of MC gels at different temperatures, the storage modulus is observed to be higher than loss modulus at lower frequencies. Both of the storage and loss modulus increases with frequency, but the rate of increase is higher for loss modulus. This leads to the first crossover between E′ and E″ during the frequency scan. For the frequency scan at a high temperature (80°C), a higher rate of increase is observed in storage modulus beyond the first crossover frequency. This leads to the second crossover between storage and loss modulus. Optical microscopy results indicate the presence of core–shell microstructure in aqueous MC gels. The first crossover is possibly due to the shell–sol transition, whereas the second crossover is due to the sol–shell–core transition. The validity of scaling laws at and around the first‐crossover point (shell–sol transition) is checked. The scaling law is valid at the first‐crossover point, but it is invalid around it. Alternate scaling equations based on reduced parameters are also used to check the universality. Irrespective of temperature, scaling laws are valid for reduced parameters. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermal and mechanical properties of acrylated expoxidized‐soybean oil‐based thermosets
Authors: Fu Liyu , Yang Liting , Dai Chunlan , Zhao Chengshan , Ma Lijun
Published: April 2010

A series of epoxidized‐soybean oil (ESO) with different epoxyl content were synthesized by in situ epoxidation of soybean oil (SBO). The acrylated epoxidized‐soybean oil (AESO) was obtained by the reaction of ring opening of ESO using acrylic acid as ring opener. The acrylated expoxidized‐soybean oil‐based thermosets have been synthesized by bulk radical polymerization of these AESOs and styrene. The thermal properties of the resins were characterized by differential scanning calorimetry (DSC) and thermo‐gravimetric analysis (TG). The results showed that these resins possess high thermal stability. There were two glass transition temperature of each resin due to the triglycerides structure of the resins. The tensile strength and impact strength of the resins were also recorded, and the tensile strength and impact strength increased as the iodine value of ESO decreased. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of corona discharge and chitosan surface treatment on dyeing properties of wool
Authors: Ristić Nebojša , Jovančić Petar , Canal Cristina , Jocić Dragan
Published: April 2010

In this work, the effects of single and combined corona discharge (CD) and biopolymer chitosan treatment (CS) on the sorption properties and dyeability of woolen fabric were studied. Physical and chemical changes on the fiber surface were assessed by using different methods. It has been confirmed that wettability and dyeability of wool were improved after single and combined treatments. The changes in elemental composition of wool fiber surface were followed by means of X‐ray photoelectron spectroscopy. The relationship between chemical changes and both wettability and dyeability after CS is discussed. On chitosan treated samples, the color intensity increased uniformly with increasing chitosan concentration. The samples treated with combined treatment (corona/chitosan) had the highest color intensity, due to synergistic effect of the treatments. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
High density polyethylene/micro calcium carbonate composites: A study of the morphological, thermal, and viscoelastic properties
Authors: Elleithy Rabeh H. , Ali Ilias , Ali Muhammad Alhaj , Al‐Zahrani S. M.
Published: April 2010

High density polyethylene (HDPE) with micro calcium carbonate (CaCO3) masterbatch was pelletized by using a twin screw extruder and different ASTM specimens were molded by an injection molding machine. The morphology of the composites was characterized by scanning electron microscopy (SEM) and Image Analysis software. The dispersion and interfacial interaction between CaCO3 and the polymer matrix were also investigated by SEM. The thermal properties of HDPE and its composites were investigated by differential scanning calorimetry (DSC). The crystallization process of the composites samples was found to be slightly different than that of the neat HDPE. Otherwise, the presence of CaCO3 did not have a considerable effect on the melting behavior of the composites. Thermogravimetric analysis (TGA) revealed that the composites had better thermal stability than the neat HDPE resin as indicated by a higher temperature of 50% weight loss (T50%) for the composites as compared to that of the neat resin. The viscoelastic properties of the composites and HDPE were also investigated via torsional and rotational techniques. The presence of CaCO3 increased the shear modulus at low frequency of the composites at 80°C over that of the neat resin. However, at higher frequencies, the difference between the neat resin and the composites' shear modulus was less than that at low frequencies. The complex viscosity of the composite increased upon the addition of CaCO3. However, the shear sensitivities of the neat resin and the microcomposite were similar. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Liquefied petroleum gas desulfurization by HTBN/PAN composite membrane
Authors: Chen Jian , Chen Jinxun , Li Jiding , Han Xiaolong , Zhan Xia , Chen Cuixian
Published: April 2010

Hydroxyl‐terminated polybutadiene/acrylonitrile (HTBN) polymer material was selected for deep desulfurization of liquefied petroleum gas (LPG) according to the solubility parameter method, and then crosslinked HTBN membranes were prepared, in which asymmetric polyacrylonitrile (PAN) membranes prepared with phase inversion method acted as the microporous supporting layer in the flat‐plate composite membrane. The different function compositions of composite membranes were characterized by reflection FTIR in order to investigate the crosslinking reaction. The surface and section of composite membranes were investigated by scanning electron microscope (SEM). The composite membranes prepared in this study were used in LPG for deep desulfurization. Effects of amount of HTBN and operation pressure on the desulfurization efficiency of LPG were investigated experimentally. Experiment results demonstrated that with the membrane having a HTBN layer of 11 μm, permeability parameter of methyl mercaptan came to 17,002 Barrer and that of hydrocarbon came to 504 Barrer at 30 wt % of HTBN and 0.25 MPa, which showed that the membrane used to desulfurization in LPG can achieve high‐removal efficiency. These results demonstrated that the membrane separation method could be significant in practical application for deep desulfurization of LPG. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Impact fracture behavior and damage mechanisms of PP/EVOH blends compatibilized with ionomer Zn2+
Authors: Montoya M. , Abad M. J. , Losada L. Barral , Pettarin V. , Bernal C.
Published: April 2010

In this work, the impact fracture behavior and the damage mechanisms of PP/EVOH blends compatibilized with ionomer Zn2+ were investigated, focusing on the effect of the compatibilizer and the EVOH content. Initiation energy release rate (GIC) values for the blends with EVOH content lower than 30 wt % were slightly lower or similar to that of neat PP, probably due to the premature failure induced by the presence of critical‐size flaws derived from debonding of second phase particles. However, blends with 40 wt % EVOH exhibited higher GIC values than neat PP as a result of the increased number of EVOH particles able to induce energy‐absorption mechanisms. An increase in the work of fracture values with EVOH content was also observed, especially for the blends with EVOH content above 30 wt %. Therefore, the incorporation of EVOH to PP led to blends more prone to ductile behavior than neat PP. Furthermore, Pukánszky and Maurer model was successfully applied to fit experimental data of GIC as a function of EVOH content and to confirm the lack of a significant effect of the ionomer Zn2+ on the impact fracture properties observed. Finally, from the study of the main deformation mechanisms it was established that the toughening effect of debonding of EVOH particles and subsequent ductile tearing of PP matrix around them which developed under quasi‐static stresses were not able to develop under impact loading conditions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Rheological, mechanical and morphological properties of thermoplastic vulcanizates based on high impact polystyrene and styrene‐butadiene rubber
Authors: Wang Zhaobo , Zhao Hongling , Zhao Jian , Wang Xin
Published: April 2010

Thermoplastic vulcanizates (TPVs) based on high impact polystyrene (HIPS)/styrene‐butadiene rubber (SBR) blends were prepared by dynamic vulcanization technique. The rheological, mechanical and morphological properties of the dynamically vulcanized blends were investigated systematically. As determined by capillary rheometer, the apparent viscosity of the blends decreases as the shear rate increases, indicating obvious pseudoplastic behavior. At low shear rate, the apparent viscosity of these blends is considerably higher than that of neat HIPS and decreases with the increase of HIPS concentration. The increase of HIPS content in the dynamically vulcanized blends contributes to the increase of tensile strength and hardness properties, while elongation at break and tensile set at break reach a maximum at 30 and 50 wt % of the HIPS content, respectively. The etched surfaces of the HIPS/SBR TPVs were investigated using field‐emission scanning electron microscopy, the morphological study reveals continuous HIPS phase and finely dispersed SBR elastomeric phase in the TPVs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of structure and additives on thermal stability of silicone fluids
Authors: Wu Chuan , Jin Jing , Yang Xiongfa , Dong Hong , Xu Xiaoqiu , Jiang Jianxiong
Published: April 2010

A series of polydimethylsiloxane (PDMS) polymers and poly(dimethyl‐diphenyl siloxane) (PDMS‐PMPS) copolymers were synthesized by the anionic ring‐opening polymerization method and then blended with titanium isooctoate as thermal additives. Their thermal stabilities have been investigated by TGA in an inert gas atmosphere. The temperature for 10% conversion, 50% conversion, and the temperature for the maximum rate of decomposition (MRDT) initiated from TGA curves recorded at a heating rate of 5, 10, 15, and 20°C min−1 and the apparent activation energy Ea using the FWO method as a function of conversion α indicated that the thermal stabilities of the polysiloxanes could be enhanced either by modifying the structure of the polymer or by introducing a certain amount of a thermal additive. PDMS‐PMPS copolymers with a MePhSiO segment content of 10.2 mol % and terminated by diphenylmethylsiloxyl groups exhibited optimal heat resistance. The thermal stabilities of the polysiloxanes could be further improved by introducing homogenous titanium additives and with the addition of 1550 ppm content of titanium additives, the temperature for 10% conversion, the temperature for 50% conversion, and MRDT have been found to be increased by 20.11, 71.28, and 98.67 K, respectively, relative to the unmodified PDMS‐PMPS copolymer. Fourier transform infrared (FTIR) analysis has proven the formation of a SiOTi bond in the titanium‐modified PDMS‐PMPS copolymer, which may be responsible for the efficient enhancement of its thermal stability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Friction and wear properties of solid lubricants filled/carbon fabric reinforced phenolic composites
Authors: Wang Qihua , Zhang Xinrui , Pei Xianqiang , Wang Tingmei
Published: April 2010

The carbon fabric composites (CFC) filled with the particulates of graphite, MoS2, and PTFE, respectively, were prepared by dip coating and hot press molding technique. The tribological properties of the resulting composites were investigated systematically on a model ring‐on‐block test rig under dry sliding conditions. Experimental results showed that the addition of graphite and MoS2 significantly improved the friction and wear behavior, but PTFE as filler was harmful to the improvement of the tribological properties of the CFC. Tribological tests also revealed that the CFC showed better tribological properties under higher load and exhibited worse tribological properties under higher sliding speed. Moreover, it also can be concluded that the transfer film formed on the counterpart surface during the friction process largely accounted for the friction and wear behavior of CFC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of new aromatic polyesters containing pendent naphthyl units
Authors: Honkhambe Pandurang N. , Biyani Mahesh V. , Bhairamadgi Nagendra S. , Wadgaonkar Prakash P. , Salunkhe Manikrao M.
Published: April 2010

Two bisphenols, viz., 4,4′‐[1‐(2‐naphthalenyl)ethylidene]bisphenol and 4,4′‐[1‐(2‐naphthalenyl) ethylidene]bis‐3‐methylphenol were prepared by condensation of commercially available 2‐acetonaphthanone with phenol and o‐cresol, respectively. A series of new aromatic polyesters containing pendent naphthyl units was synthesized by phase‐transfer‐catalyzed interfacial polycondensation of these bisphenols with isophthaloyl chloride, terephthaloyl chloride, and a mixture of isophthaloyl chloride/terephthaloyl chloride (50 : 50 mol %). Inherent viscosities of polyesters were in the range 0.83–1.76 dL g−1, while number average molecular weights (Mn) were in the range 61,000–235,000 g mol−1. Polyesters were readily soluble in organic solvents such as dichloromethane, chloroform, tetrahydrofuran, m‐cresol, pyridine, N,N‐dimethylformamide, N,N‐dimethylacetamide, and 1‐methyl‐2‐pyrrolidinone at room temperature. Tough, transparent, and flexible films were cast from a solution of polyesters in chloroform. X‐Ray diffraction measurements displayed a broad halo at 2θ ≅ 19° indicating the amorphous nature of polyesters. Glass transition temperatures of polyesters were in the range 209–259°C. The temperature at 10% weight loss (T10), determined by TGA in nitrogen atmosphere, of polyesters was in the range 435–500°C indicating their good thermal stability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterizations of branched poly(butylene succinate) copolymers with 1,2‐octanediol segments
Authors: Wang Guoli , Gao Bing , Ye Haimu , Xu Jun , Guo Baohua
Published: April 2010

Branched poly(butylene succinate) (PBS) copolymers were synthesized, from succinic acid (SA), 1,4‐butanediol (1,4‐BD), and 1,2‐octanediol (1,2‐OD) through a two‐step process containing esterification and polycondensation, with different mole fractions of 1,2‐OD segments. The branched PBS copolymers were characterized with 1H‐NMR, differential scanning calorimetry (DSC), wide angle X‐ray diffraction (WAXD), thermogravimetric analysis (TGA), dynamic rheological testing, and tensile properties analysis. The results of DSC and WAXD show that, with the increasing of the 1,2‐OD segments content, the glass transition temperature (Tg), melting temperature (Tm), crystallization temperature (Tc), and the degree of crystallinity (Xc) decrease. While the crystal structure of PBS does not change by introducing 1,2‐OD segments. The results of TGA and dynamic rheological testing indicate that the thermal stability of neat PBS is improved with the addition of 1,2‐OD segments. The incorporation of 1,2‐OD segments has some effects on the rheological properties of PBS, such as complex viscosities (|η*|), storage modulus (G′), and loss modulus (G″). Tensile testing demonstrates that the elongation at break is improved significantly with increasing 1,2‐OD segments content, but without a notable decrease of tensile strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
The Van der Pauw method for sheet resistance measurements of polypyrrole‐coated para‐aramide woven fabrics
Authors: Banaszczyk J. , Schwarz A. , De Mey G. , Van Langenhove L.
Published: April 2010

In this article, it is shown that the Van der Pauw (VDP) method, generally known in microelectronics, can be successfully adapted to sheet resistance measurements of electroconductive fabrics. We prepared two polypyrrole‐coated woven para‐aramide fabrics and used a simple setup to measure their sheet resistances. The results were then compared with those obtained using a sophisticated commercial collinear array probe. The measurements were done in a 1 month interval, to investigate the influence of the coating aging on the sheet resistance of the samples. The influence of the contact positioning on the accuracy of the VDP measurement was investigated. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010