bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrophotography
Authors: Hauser O. G.
Published: October 2003

Electrophotography, also called xerography, is a process for producing high quality copies or images of a document. Electrophotography is based on forming an electrostatic charge pattern or image of the original document that is made visible by ultrafine electrically charged particles.

The advent of the personal computer and desktop publishing created a need for convenient, low‐cost, point‐of‐need printing. At first, typewriters were adapted to perform impact printing, followed by dot matrix printers, but these concepts had many disadvantages. Small (and slow) ink jet printers have come to dominate the low‐volume desktop publishing market at this time. The mid‐volume and high‐volume markets, however, are presently dominated by faster and more reliable laser and light‐emitting‐diode (LED) electrophotographic printers. The print quality of these modern printers approaches that of offset lithography quite closely, so many electrophotographic machines compete effectively with the offset press. There are business advantages for each type of printer, however, and offset print shops are certainly not going to go out of business in the foreseeable future. Because of the popularity of electrophotographic printers, both large and small, color and black only, this article explores the fundamentals involved in producing hard copy by this process.

This article first presents an overview of the essential elements in an electrophotographic imaging system. Then, each of the commercialized process steps is covered in some detail to lead the reader from corona sensitization of the photoconductor to fixing of the final image. An extension of the electrophotographic process to color printing is discussed in the final section.

In a form of electrophotography called xeroradiography, the X‐ray portion of the electromagnetic spectrum is used to form a latent image on a photoconductor.
Deletion of the distal long arm of chromosome 10; is there a characteristic phenotype? A report of 15 de novo and familial cases
Authors: Irving Melita , Hanson Helen , Turnpenny Peter , Brewer Carole , Ogilvie Caroline Mackie , Davies Angela , Berg Jonathan
Published: October 2003

It has been suggested previously that patients with terminal deletions of chromosome 10q have a recognizable phenotype including a characteristic facial appearance combined with other abnormalities including mental retardation, cardiac and anogenital anomalies. We report the largest published series of new cases of terminal 10q deletion, including eight familial and four de novo cases and three cases with interstitial deletions involving chromosome bands 10q25.2‐26.3. The deleted regions were defined by FISH using YAC probes, as well as standard karyotyping. The most consistent clinical features in our cases are cranial anomalies including facial asymmetry, prominent nose and nasal bridge, prominent ears, thin upper lip, along with growth retardation, developmental delay, and digital abnormalities. Visceral abnormalities were only identified in a small number of the patients, with renal involvement in three cases and structural cardiac malformations in two others. Learning difficulties of varying severity were found in 11 cases and behavioral problems described in four. Candidate genes for behavioral and learning difficulties within the deleted region include Calcyon. Other genes in the region that might have a role in causing the phenotype include the genes coding for fibroblast growth factor receptor type 2 (FGFR2) and C‐terminal binding protein 2 (CTBP2). © 2003 Wiley‐Liss, Inc.
Preliminary data on changes in neural tube defect prevalence rates after folic acid fortification in South America
Authors: Castilla Eduardo E. , Orioli Iêda M. , Lopez‐Camelo Jorge S. , Dutra Maria da Graça , Nazer‐Herrera Julio ,   for the ECLAMC: Latin American Collaborative Study of Congenital Malformations
Published: October 2003

Several South American countries are fortifying wheat flour with folic acid. However, only Chile started in 2000 to add 2.2 mg/kg, providing 360 μg daily per capita, an acceptable dosage for preventing the occurrence of some neural tube defect (NTD) cases. ECLAMC (Spanish acronym for the Latin American Collaborative Study of Congenital Malformations) routinely monitoring birth defects in South America since 1976, surveyed the impact of this fortification. Data from 361,374 births occurred in 43 South American hospitals, distributed in five different countries, active throughout the 1999–2001 triennium, were selected from the ECLAMC network. Birth prevalence rates for three different congenital anomalies with similar expected prevalence rates, were surveyed by the Cumulative Sum Method (CUSUM) method. They were NTD, oral clefts (OC), and Down syndrome (DS). Expected values were derived from observations made in 1999, and CUSUM was applied to the consecutive series of 24 months covering years 2000 and 2001. Only one of three congenital anomaly types, NTDs, in only one of five sampled out countries, Chile, showed a significant decrease, of 31%, during the 2000–2001 biennium, corresponding to the birth of the periconceptionally fortified infants. The level of significance (P < 0.001) was reached in the 20th month after fortification started, corresponding to August 2001. This is the first observation of a significant decrease in the occurrence of NTD after folic acid food fortification in a population little influenced by confounders common in the developed world as pre‐existing secular decreasing trends, and partially unregistered induced abortions. © 2003 Wiley‐Liss, Inc.
A genome‐wide scan for loci predisposing to non‐syndromic cleft lip with or without cleft palate in two large Syrian families
Authors: Wyszynski Diego F. , Albacha‐Hejazi Hasan , Aldirani Mohammed , Hammod Moustafa , Shkair Hikmat , Karam Ahmed , Alashkar Jehad , Holmes Taura N. , Pugh Elizabeth W. , Doheny Kimberly F. , McIntosh Iain , Beaty Terri H. , Bailey‐Wilson Joan E.
Published: October 2003

Non‐syndromic cleft lip with/without cleft palate (CL/P) is a common, usually non‐fatal birth defect of complex etiology. Several segregation analyses have demonstrated that genetic factors are important in the pathogenesis of CL/P, most likely through the interaction of several genes of modest effects. The aim of this study was to perform a genome‐wide linkage analysis to identify/search for candidate gene loci for CL/P. We conducted a genome‐wide search in two large, relatively isolated Syrian families, each one with a large number of cases with CL/P (18 in family 1 and 4 in family 2). A locus with a multipoint LOD score of 2.80 and a 2‐point non‐parametric MLS LOD of 3.0 was detected on 17p13.1. Other chromosomal regions with multipoint LOD scores ≥ 1.2 (P ≤ 0.01) included 3p21.2, 4q32.1, and 7q34. These data indicate the possible presence of several susceptibility loci for CL/P and identify a strong candidate locus for this common birth defect on chromosome 17p13. Published 2003 Wiley‐Liss, Inc.
Werner mesomelic dysplasia with Hirschsprung disease
Authors: Goldenberg Alice , Milh Mathieu , de Lagausie Pascal , Mesnage Renaud , Benarif Fatiha , De Blois Marie‐Christine , Munnich Arnold , Lyonnet Stanislas , Cormier‐Daire Valérie
Published: October 2003

Mesomelic dysplasia type Werner is defined by absence of tibiae and preaxial polysyndactyly of hands and feet. Occasional findings are triphalangeal thumbs, absence of patella(e), and dislocated fibula(e). The molecular basis is unknown and autosomal dominant inheritance with variable expressivity is currently postulated. Hirschsprung disease was reported previously in one case. We report here on a new case of mesomelic dysplasia Werner type associated with Hirschsprung disease and bilateral cryptorchidism. We discuss the overlap with the triphalangeal thumb polysyndactyly syndrome located in chromosome 7q36. © 2003 Wiley‐Liss, Inc.
Clinical homogeneity and genetic heterogeneity in Weill–Marchesani syndrome
Authors: Faivre Laurence , Dollfus Hélène , Lyonnet Stanislas , Alembik Yves , Mégarbané André , Samples John , Gorlin Robert J. , Alswaid Abdulrahman , Feingold Josué , Le Merrer Martine , Munnich Arnold , Cormier‐Daire Valérie
Published: October 2003

Weill–Marchesani syndrome (WMS) is a rare condition characterized by short stature, brachydactyly, joint stiffness, and characteristic eye abnormalities including microspherophakia, ectopia of lens, severe myopia, and glaucoma. Both autosomal recessive (AR) and autosomal dominant (AD) modes of inheritance have been described for WMS. A locus for AR WMS has recently been mapped to chromosome 19p13.3‐p13.2 while mutation within the fibrillin‐1 gene (15q21.1) was found in one AD WMS family. In order to answer the question of whether or not genetic heterogeneity could be related to a clinical heterogeneity, we reviewed 128 WMS patients from the literature (including 57 AR, 50 AD, and 21 sporadic cases), with a particular attention to clinical features. Statistical analyses using Fischer exact test were used to compare the proportions of 12 clinical parameters between AR and AD patients. There was no significant difference between both groups for myopia, glaucoma, cataract, short stature, brachydactyly, thick skin, muscular build, and mental retardation. Significant results were found for microspherophakia (94% in AR, 74% in AD, Fischer 0.007), ectopia lentis (64% in AR, 84% in AD, Fischer 0.016), joint limitations (49% in AR, 77% in AD, Fischer 0.010), and cardiac anomalies (39% in AR, 13% in AD, Fischer 0.004). Nevertheless, we failed to distinguish AR from AD inheritance in individual cases. These results support the clinical homogeneity but the genetic heterogeneity of WMS. © 2003 Wiley‐Liss, Inc.
Crisponi syndrome: Report of a further patient
Authors: Accorsi P. , Giordano L. , Faravelli F.
Published: October 2003

Crisponi syndrome was described in the original paper in 17 patients form 12 families [Crisponi, 1996: Am J Med Genet 62:365–371]. It is characterised by episodes of muscle contraction in response to external stimuli and intermittent hypethermia with neonatal onset. The disease is often lethal in the first infancy. We describe a patient with the same unusual phenotype. © 2003 Wiley‐Liss, Inc.
Early renal insufficiency in a neonate with de novo partial trisomy of chromosome 10q
Authors: Varda Nataša Marčun , Kokalj Vokač N. , Kanič Z. , Bračič K. , Erjavec A. , Zagradišnik B. , Gregorič A.
Published: October 2003

Partial trisomy of the long arm of chromosome 10 is a well‐defined but rare syndrome. Clinical features of this chromosomopathy are a distinctive dysmorphic appearance, developmental delay, growth retardation, and in some cases, abnormalities of the extremities and renal, cardiac and ocular anomalies. This report describes a neonate with symmetric growth retardation and multiple dysmorphic features, in whom chromosomal analysis revealed a partial trisomy of chromosome 10q with a monosomy of the 13q34 region. The phenotype shares many common features with previously published cases. In addition to the typical features, our case also shows renal hypoplasia with early renal insufficiency and some genital anomalies. © 2003 Wiley‐Liss, Inc.
Novel mutation in the 5′ splice site of exon 4 of theTCOF1gene in the patient with Treacher Collins syndrome
Authors: Marszalek Bozena , Wisniewski Slawomir A. , Wojcicki Piotr , Kobus Kazimierz , Trzeciak Wieslaw H.
Published: October 2003

Treacher Collins syndrome (TCS) is caused by mutations in theTCOF1gene. This gene encodes a serine/alanine‐rich protein called treacle. The structure of the entireTCOF1gene was investigated in a patient with TCS. We detected a novel deletion (376delAAGGTGAGTGGGACTGCC) spanning 3 bp of exon 4 and 15 bp of the adjacent intronic sequence. This mutation causes premature termination of translation, resulting in a truncated protein devoid of nucleolar localization signal, and potential phosphorylation sites. Real‐time PCR analysis showed different melting temperatures of the amplified fragment containing normal allele and that harboring the 18 bp deletion, thus providing a rapid screening assay for this and other deletions of theTCOF1gene. © 2003 Wiley‐Liss, Inc.
Chromosome instability induced in vitro with mitomycin C in five Seckel syndrome patients
Authors: Bobabilla‐Morales Lucina , Corona‐Rivera Alfredo , Corona‐Rivera J. Román , Buenrostro C. , García‐Cobián Teresa A. , Corona‐Rivera Enrique , Cantú‐Garza José María , García‐Cruz Diana
Published: October 2003

Seckel syndrome (SS) is an autosomal recessive entity characterized by proportionate pre‐ and post‐natal growth retardation, microcephaly, typical facial appearance with beak‐like protrusion, and severe mental retardation. A heterogeneous basis for SS was proposed since around 25% of SS patients have hematological anomalies, suggesting a subgroup of SS with chromosome instability and hematological disorders. Chromosome instability induced by mitomycin C (MMC) has been observed in previous reports. The purpose of this study is to report cytogenetic features in five patients with SS. The patients had low birth weight (mean 1,870 g), short stature (SD = 6.36), microcephaly (OFC, SD = 8.1), typical facial appearance, and multiple articular dislocations. None of them had anemia at the time of examination. In all cases their parents were healthy and non‐consanguineous. Lymphocytes of SS patients and a control group (n = 9) matched by age and sex were cultured with and without MMC, and harvested at 72 and 96 hr. Chromosomal aberrations (chromatid and chromosomal gaps and breaks, deletions, fragments, and exchanges) were scored in 100 metaphases per culture. A statistical increase of chromosomal aberrations was observed in 96 hr MMC cultures in all patients (40.2% vs. 2.8%). Sister chromatid exchanges were also performed with no differences between groups. Clinical and cytogenetic findings support the idea that SS may correspond to a chromosome instability syndrome. © 2003 Wiley‐Liss, Inc.
Preparation of ion‐exchange membranes by the hydrolysis of radiation‐grafted polyethylene‐g‐polyacrylamide films: Properties and metal‐ion separation
Authors: Gupta Bhuvanesh , Anjum Nishat
Published: October 2003

Ion‐exchange membranes were prepared by the alkaline hydrolysis of radiation‐grafted polyethylene‐g‐polyacrylamide membranes. The hydrolyzed membranes showed a good water uptake of approximately 1060 for a graft level of 590%. The electrical resistance of the membranes decreased with an increase in the degree of grafting up to 200% and then stabilized with further increases in the graft level. The membranes had an excellent binding capacity for mercury ions. The metal‐binding capacity increased with an increase in the degree of grafting in the membranes. A binding capacity as high as 7.2 mmol/g in a membrane with 590% grafting was achieved. The pH of the metal solution had a significant influence on the binding ability of the membranes. The partial hydrolysis of the grafted membranes contributed to the higher binding because of the expansion of the bulk structure by ionized carboxyl groups and the better accessibility of mercury to amide groups. The mercury‐loaded membranes showed thermal stability inferior to that of membranes without metal binding. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3747–3752, 2003
Miscibility and crystallization behavior of poly(3‐hydroxyvalerate‐co‐3‐hydroxyvalerate)/ poly(propylene carbonate) blends
Authors: Peng Shuwen , An Yuxian , Chen Cheng , Fei Bin , Zhuang Yugang , Dong Lisong
Published: October 2003

Blends of synthetic poly(propylene carbonate) (PPC) with a natural bacterial copolymer of 3‐hydroxybutyrate with 3‐hydroxyvalerate (PHBV) containing 8 mol % 3‐hydroxyvalerate units were prepared with a simple casting procedure. PPC was thermally stabilized by end‐capping before use. The miscibility, morphology, and crystallization behavior of the blends were investigated by differential scanning calorimetry, polarized optical microscopy, wide‐angle X‐ray diffraction (WAXD), and small‐angle X‐ray scattering (SAXS). PHBV/PPC blends showed weak miscibility in the melt, but the miscibility was very low. The effect of PPC on the crystallization of PHBV was evident. The addition of PPC decreased the rate of spherulite growth of PHBV, and with increasing PPC content in the PHBV/PPC blends, the PHBV spherulites became more and more open. However, the crystalline structure of PHBV did not change with increasing PPC in the PHBV/PPC blends, as shown from WAXD analysis. The long period obtained from SAXS showed a small increase with the addition of PPC. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4054–4060, 2003
Oil‐absorption function of physical crosslinking in the high‐oil‐absorption resins
Authors: Shan Guo‐Rong , Xu Ping‐Ying , Weng Zhi‐Xue , Huang Zhi‐Ming
Published: October 2003

The concept of physical crosslinking was introduced into the research field of oil‐absorption resins, which were traditionally synthesized only by chemical crosslinking. Specifically, the partially physical crosslinking acrylic series for high‐oil‐absorption resins were prepared in the suspension process, and the swelling behavior of the samples was observed and recorded online. This demonstrated that a kind of relaxing three‐dimensional network was indeed formed by the introduction of polybutadiene (PB). The effects of monomer feed ratios, crosslinking agent concentration and type, particle size, and temperature on the oil absorbency and oil‐absorption speed were investigated. The results indicated that there were an optimum monomer feed ratio and an optimum amount of ethylene glycol dimethacrylate or PB. In addition, the particle size and temperature had a serious influence on the oil‐absorption speed in comparison with the monomer feed ratio and the crosslinking agent concentration and type. The results also showed that particle size affected oil absorbency to a great degree and that the effect of temperature on oil absorbency was complex. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3945–3950, 2003
Assessment of cyclization and network defects in glycidylamine‐based epoxy networks by selective degradation
Authors: Stutz Herbert , Tesch Helmut
Published: October 2003

A special model system based on trimethylene glycol di(p‐aminobenzoate) and its glycidyl derivative was evaluated to study the extent of cyclization in glycidylamine epoxies. The cured resins were degraded by alkaline hydrolysis, which left the cycles unaffected. The cycle concentration obtained by high‐performance liquid chromatography was 15%. The oligomer distribution of the degradation products strongly indicated that up to 40% of the epoxy groups were lost to side reactions, and this resulted in a large number of structural defects in the network. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3951–3956, 2003
Anionic copolymerization of lauryl lactam and polycaprolactone for the production of a poly(ester amide) triblock copolymer
Authors: Kim In , White James L.
Published: October 2003

This article examines the anionic polymerization of lauryl lactam into polyamide 12 and the copolymerization of lauryl lactam with a diisocyanate‐end‐capped polycaprolactone used to produce a poly(ester amide) block copolymer. The molecular weights of the polyester polyols used in the preparation of the diisocyanate‐end‐capped polycaprolactone were varied. The products were characterized with Fourier transform infrared spectroscopy and differential scanning calorimetry, and the mechanical properties were measured in a mechanical tester. The influence of the polyol molecular weight was considered. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3797–3805, 2003
Cure kinetics and thermomechanical properties of thermally stable photopolymerized dimethacrylates
Authors: Cook Wayne D. , Forsythe John S. , Irawati Nova , Scott Timothy F. , Xia Wilson Z.
Published: October 2003

A range of dimethacrylates with varying backbone flexibility were partially photocured to various conversions using p‐xylylene bis‐(N,N‐diethyldithiocarbamate) as a photoiniferter and their glass transition region investigated by dynamic mechanical thermal analysis. For isothermally cured samples, the final degree of conversion was found to increase as the length of the spacer group in the monomer was increased or as the crosslink density in the resin was lowered due to the reduced glass transition temperature which allowed greater mobility and, hence, higher cure. Increasing the curing temperature also resulted in a higher degree of conversion as the network was able to polymerize further before vitrification occurred. For the partially photocured samples, the glass transition temperature was raised as the degree of conversion was increased. Most of the measures of the breadth of the glass transition were found to increase with increased conversion for dimethacrylates with short or stiff backbones (TETDMA and bisGMA) while the transition breadth was independent of conversion for either a more flexible dimethacrylate (NEGDMA) or a dimethacrylate network with a lower crosslink density (50 wt % bisGMA/50 wt % PGEMA). This conclusion was generally confirmed by analysis of the viscoelastic parameters in the frequency domain. It is not clear whether these behaviors resulted from differences in the range of molecular motions available in tight networks or if they were due to spatially heterogeneous regions in the network. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3753–3766, 2003
Influences of individual and composed poly(vinyl alcohol) suspending agents on particle morphology of suspension poly(vinyl chloride) resin
Authors: Bao Yong‐Zhong , Liao Jian‐Gang , Huang Zhi‐Ming , Weng Zhi‐Xue
Published: October 2003

Effects of individual and composed poly(vinyl alcohol) (PVA) suspending agents on the particle morphology of poly(vinyl chloride) (PVC) resins were investigated and discussed in the view of PVA absorption at the oil/water interface and interfacial behavior. It was shown that the percentage and surface coverage of PVA at the oil/water interface decreased with the increase of the degree of hydrolysis (DH) of PVA in the DH range of 70–98 mol %, while the interfacial tension of VC/PVA aqueous solution increased linearly with the increase of DH of PVA. PVC resin with more regular particle shape, increased agglomeration and fusion of primary particles, lower porosity and higher bulk density, was prepared by using PVA with a higher DH as a suspending agent. This was caused by the occurrence of drop coalescence at the very early stage of VC polymerization, the increase of particle shrinkage, and the lower colloidal protection to primary particles. It was also shown that the interfacial tension of VC/water in the presence of composed PVA suspending agents varied linearly with the weight composition of the composed PVA suspending agents. The particle properties of PVC resin prepared by using the composed PVC suspending agents were usually situated in between the properties of PVC resins prepared by using the corresponding individual PVA suspending agent. The particle morphology and properties of PVC resin could be controlled by the suitable choice of the composed PVA suspending agents. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3848–3855, 2003
Nucleating activity of the quinacridone and phthalocyanine pigments in polypropylene crystallization
Authors: Broda Jan
Published: October 2003

The nucleating ability of two organic pigments, quinacridone and phthalocyanine, in nonisothermal polypropylene (PP) crystallization was investigated. The investigations were carried out using DSC and polarizing microscopy. The efficiency of pigments in the nucleation process was determined in a simple test comparing the crystallization temperature of the PP‐containing pigments with respect to the pure polymer. Both pigments revealed good nucleating activity. In the presence of pigments the increment of the crystallization temperature and the increase of nucleation rate were observed. The nucleating efficiency of pigments was confirmed in investigations of the obtained structure. The nucleating activity of pigments was explained by their features fulfilling several requirements for good nucleating agents. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3957–3964, 2003
Preparation of hemispherical poly(4‐vinylpyridine‐co‐butyl acrylate)/poly(styrene‐co‐butyl acrylate) composite microspheres by seeded preswelling emulsion polymerization
Authors: Han Shao‐Hua , Ma Guang‐Hui , Du Yong‐Zhong , Omi Shinzo , Gu Li‐Xia
Published: October 2003

Seeded preswelling emulsion polymerization was carried out by using monodispersed poly(4‐vinylpyridine‐co‐butyl acrylate) [P(4VP‐BA)] particles as the seed, and styrene and butyl acrylate as the second‐stage monomers under different polymerization conditions, to obtain hemispherical polystyrene (PST)‐rich–P4VP‐rich microspheres. Prior to polymerization, toluene was added into the preswelling system together with the second‐stage monomers. It was found that, with the increase of the amount of toluene, the particle morphology showed a tendency toward desirable hemispherical structure, and the colloidal stability of composite latex was improved. When the weight ratio of toluene/seed latex was increased up to 7.5/40 (g/g), the stable hemispherical latex could be obtained. However, when toluene was not added, the coagulum formed on the wall of the reactor during polymerization, and the composite particles with multiple surface domains (such as sandwich‐like, popcorn‐like) were formed. In addition, the final morphology of composite particles was influenced by the polarity of the seed crosslinker and the hydrophilicity of the second‐stage initiator, which could affect the mobility of poly(styrene‐co‐butyl acrylate) [P(ST‐BA)] chains. The morphology development during the polymerization was investigated in detail, and a schematic model was derived to depict the formation mechanism of hemispherical P(4VP‐BA)/P(ST‐BA) composite microspheres. The results revealed that the mobility of the P(ST‐BA) chains influenced the diffusion of the P(ST‐BA) domains on the surface of the P(4VP‐BA) matrix. When the mobility of the P(ST‐BA) chains allowed small‐size P(ST‐BA) domains to coalesce into one larger domain, complete phase‐separated morphology (hemisphere) could be achieved. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3811–3821, 2003
Study of the influence of nejayote and other additives on the cohesive strength and electric properties of carbon black agglomerates
Authors: González Regino , Reguera Edilso , Figueroa Juan M. , De La Luz Martínez José
Published: October 2003

An investigation was carried out on the influence of nejayote and other additives (water, potassium lignosulfonate, and furfuryl alcohol), on the cohesive strength and electrical properties of carbon black agglomerates. The thermal stability of carbon black agglomerates with potassium lignosulfonate and nejayote was similar. The influence of nejayote and potassium lignosulfonate on the cohesive strength of carbon black agglomerates was also similar but the electrical properties were different. The carbon black agglomerates with nejayote have a lower electrical conductivity. The influence of water on the cohesive strength of carbon black agglomerates was not significant but it was important in their electrical conductivity. Nejayote, a waste by‐product from the corn‐processing industry, appears as a potential agglutinant in the carbon black pelletization process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3965–3972, 2003
Immobilization of chitosan on nylon 6,6 and pet granules through hydrolysis pretreatment
Authors: Zhang X. , Bai Renbi
Published: October 2003

Chitosan has been increasingly studied as an adsorbent for removing heavy metal ions and organic compounds from aqueous solutions. Most of the studies used chitosan in the form of flakes, powder, or hydrogel beads. This research investigates the immobilization of chitosan on other granular materials to overcome the poor mechanical property of chitosan and offers the potential for chitosan to be used as a regenerable adsorbent. Nylon 6,6 and poly(ethylene terephthalate) (PET) granules were partially hydrolyzed under an acidic or alkaline condition to allow chitosan to be coated or immobilized on the granules' surfaces. The surface morphologies of nylon 6,6 or PET granules before and after hydrolysis and those with immobilized chitosan layer were examined by scanning electron microscopy (SEM), and their surface properties were characterized through ζ‐potential analysis and X‐ray photoelectron spectroscopy. The immobilization of chitosan on nylon 6,6 or PET granules was identified to be through the formation of the salt structure (–NH…−OOC–) between the surfaces of hydrolyzed nylon 6,6 or PET granules and the chitosan layer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3973–3979, 2003
Effect of high polymerization temperature on the microstructure of isotactic polypropylene prepared using heterogeneous ticl4/mgcl2 catalysts
Authors: Zhong Chifeng , Gao Mingzhi , Mao Bingquan
Published: October 2003

The effects of alkylaluminum and polymerization temperature on propylene polymerization without an external donor in the use of a TiCl4–MgCl2–diether(BMMF) catalyst were investigated. The results indicated that with increasing polymerization temperature the concentrations of [mmmm] of heptane‐insoluble poly(propylene) (PP) fraction increased. Crystallization analysis fractionation (CRYSTAF) results showed the fractions of different crystallization temperatures were changed according to various polymerization temperatures. The activity with Et3Al as cocatalyst at 100°C was much lower than that at 70°C. However, the activity with i‐Bu3Al at 100°C was as high as that at 70°C. The fraction of high‐crystallization temperature of PPs obtained with i‐Bu3Al increased with increasing polymerization temperature, which was opposite to that with Et3Al, thus implying that the copolymerization of propylene with the monomer arising from Et3Al led to the lower crystallization ability of PPs obtained with Et3Al. The terminal groups of PP suggested that the chain‐transfer reaction by β‐H abstraction was the main chain‐transfer reaction at 120°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3980–3986, 2003
Peroxydisulfate initiated graft copolymerization of aniline onto poly(propylene) fiber—A kinetic approach
Authors: Anbarasan R. , Jayaseharan J. , Sudha M. , Gopalan A.
Published: October 2003

A novel method for the preparation of electrically conducting fibers through chemical grafting of electrically conducting polymer onto poly(propylene) (PP) fiber is described. The graft copolymerization of aniline (ANI) was performed in aqueous acidic medium by using a chemical oxidant such as peroxydisulfate (PDS). Grafting occurred with simultaneous homopolymer formation. The content of polyaniline in the backbone fiber was found to vary by varying [monomer], [initiator], and amount of PP fiber. Various graft parameters such as rate of grafting (Rg), % grafting, and % grafting efficiency were evaluated. The rate of homopolymerization (Rh) was also determined. Both Rh and Rg showed first‐order dependency on [ANI], [PDS], and amount of PP fiber variation. The chemical grafting was confirmed by use of cyclic voltammetry and conductivity measurements. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3827–3834, 2003
Synthesis and characterization of new hydrogels on the basis of water‐soluble maleic anhydride copolymers with γ‐aminopropyltriethoxysilane
Authors: Kaplan Can Hatıce , Rzaev Zakır M. O. , Güner Alı
Published: October 2003

This work describes the synthesis and macromolecular reactions of maleic anhydride (MA)–acrylic acid (AA) binary reactive copolymers with γ‐aminopropyltriethoxysilane (APTS) as a polyfunctional crosslinker. Copolymers with a given composition of MA–AA (47.17–52.83 wt %) were synthesized by radical binary copolymerization with benzoyl peroxide as an initiator in p‐dioxane at 70°C in nitrogen atmosphere and initial monomer ratio of 1 : 1. It is shown that the network structure is formed in MA–AA/APTS in water by intermolecular reaction between the anhydride unit and the amine group, as well as between the etoxysilyl fragment and free carboxyl groups of the acrylic acid and maleic anhydride unit. Swelling parameters such as beginning time of hydrogel formation, initial rate of swelling, swelling rate constant, equilibrium swelling, and equilibrium water content were determined for copolymer/APTS/water systems with various copolymer/crosslinker ratios. Formation of a hyperbranched network structure through the fragmentation of side‐chain reactive groups in the studied systems was confirmed by FTIR, TGA, and DSC methods. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4009–4015, 2003
Effects of temperature and stress level on creep and tensile property of polypropylene sutures
Authors: Deng Meng , Zhou Jack
Published: October 2003

An investigation was conducted on creep behaviors of polypropylene sutures under different temperatures and stress levels in a temperature‐controlled water bath. The study showed that temperature and stress level significantly affected the creep behaviors of the sutures. High temperature and stress level resulted in large creep and permanent deformation to the sutures. The creep data could be well described by an empirical formula. For most of the test conditions, the creep tests caused limited permanent deformation in sutures. Dependency of the permanent deformation on temperature may be illustrated by an Arrhenius‐type equation. The tensile properties of the sutures were not adversely affected by a short‐term creep test, indicating good mechanical performance for the polypropylene sutures. For the creep experiment of less than 3 h, the creep rupture of the sutures was observed at a stress level of 220 MPa and temperatures ≥ 37°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3882–3888, 2003
Temperature effects of electrical resistivity of conductive silicone rubber filled with carbon blacks
Authors: Zhang Jie , Feng Shengyu
Published: October 2003

The temperature effects of electrical resistivity of conductive silicone rubber filled with widely varying concentrations of carbon blacks (CBs: GPF 660 carbon black, HAF N‐330 carbon black, VXC‐72 conductive carbon black, and BP2000 superconductive carbon black) were studied from 30 to 200°C. Both low positive temperature coefficient (L‐PTC) and negative temperature coefficient (NTC) phenomena were observed, whose intensity and temperature range depend on the type and the concentration of CBs. A stronger temperature dependency of resistivity was observed when the CB concentration was in the percolation region. Unlike crystalline polymers/CBs composites, the high positive temperature coefficient (H‐PTC) phenomenon was not observed in CB‐filled silicone rubber when the CB concentration was near the percolation threshold. Generally, pronounced the NTC phenomenon appears in composites with small particles of CBs at concentrations near the percolation threshold, whereas a pronounced PTC phenomenon appears in composites with large CB particles of at concentrations exceeding the percolation region. If both PTC and NTC phenomena were in the same sample of conductive silicone rubber, the PTC phenomenon always appeared at relatively low temperatures and NTC at relatively high temperatures. The results were discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3889–3895, 2003
Influence of additional thermal stabilizers on the reprocessing of postconsumer poly(vinyl chloride) bottles
Authors: Ulutan Sevgi
Published: October 2003

The addition of heat stabilizers is essential for preventing the degradation of poly(vinyl chloride) (PVC) during its processing. The heat stabilizers consumed in the first run have to be made up before the reprocessing of recycled PVC. In this study, solvent‐cast films, which were prepared from granulated postconsumer PVC bottles mixed with plasticizers and thermal stabilizers, were used. The films were subjected to various heat treatments. No considerable structural change upon heat treatments at 140–160°C was found in IR and differential scanning calorimetry analyses. Polyene formation observed through ultraviolet analysis was not severe, indicating that the added stabilizers worked well in preventing degradation. The weight loss during the heat treatments was attributed partly to the decomposition of PVC and the evaporation of volatile components and mainly to the removal of the solvent upon heating. Although this study was conducted with water bottles that were to be recycled, it may be equally well applied to other similarly formulated PVC‐based materials, such as packaging films. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3994–3999, 2003
Use of rice bran oil and epoxidized rice bran oil in carbon black–filled natural rubber–polychloroprene blends
Authors: Kuriakose A. P. , Varghese Mohan
Published: October 2003

In the present study we report the results obtained on the use of rice bran oil (RBO), a naturally occurring nontoxic oil, and its epoxidized variety (epoxidized RBO, or ERBO) in the compounding and vulcanization of different natural rubber–chloroprene rubber (NR–CR) blends. The processability, cure characteristics, and physical properties of the blends prepared with these oils were compared with those of control mixes prepared with aromatic oil. The optimum cure time and scorch time values of the different blends prepared with these oils were found to be lower than those of the respective control blends prepared with aromatic oil. Evaluation of physical properties of the different experimental blends showed that replacement of aromatic oil with these oils did not adversely affect their physical properties. Because RBO contains a good amount of free fatty acids it was tried as a coactivator in addition to its role as a processing aid. The level of these oils required for the blend preparation was optimized in a Brabender plasticorder. Physical properties such as tensile strength, elongation at break, tear strength, swelling index, and abrasion loss, for example, were evaluated for both experimental and control mixes. Comparison of cure characteristics and physical properties of the blends prepared with aromatic oil and with these oils showed that these oils could be used in place of aromatic oil in the above blends. It is also to be noted that aromatic oil is of petroleum origin and is reported to be carcinogenic. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4084–4092, 2003
Postgrafting of congo red dye onto hyperbranched mesoporous silica with terminal amino groups
Authors: Seçkin Turgay , Gültek Ahmet
Published: October 2003

Congo red dye has been postgrafted onto mesoporous silica that was prepared by the controlled hydrolysis of tetraethyl orthosilicate in the presence of organic agents. Surface grafting of mesoporous silica having amino groups as initiator sites was prepared from γ‐aminopropyltrimethoxysilane by sol‐gel process. The postgrafting reaction of Congo red onto silica with terminal amino groups was achieved by a repeated step of the addition of methyl acrylate to amine groups followed by the amidation of the resulting ester moieties with ethylene diamine. Postgrafting efficiency of all materials has been outlined. Because postgrafting efficiency values have been found to be smaller than theoretical values, it is concluded that the resulting product was more likely to be a hyperbranched polymer rather than a true dendrimer at higher generations. The postgrafted structures with amino‐terminal groups provide an attractive site for binding Congo red dye that not only persists in its characteristic properties, but also has exceptional hybrid properties possessed by mesoporous silica. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3905–3911, 2003
Effect of membrane morphology in pervaporative separation of isopropyl alcohol–aromatic mixtures— a thermodynamic approach to membrane selection
Authors: Mandal Sangita , Pangarkar Vishwas G.
Published: October 2003

Isopropyl alcohol (IPA)–benzene and IPA–toluene, which forms azeotropic mixtures, are commonly encountered in pharmaceutical industries. The present study deals with the use of pervaporation to separate these mixtures. For this purpose, several polymeric hydrophilic membranes with variation in solubility parameters such as regenerated cellulose or cellophane, poly(vinyl alcohol) (PVA), cellulose acetate (CA), cellulose diacetate (CDA), and cellulose triacetate (CTA) were studied. Some of these membranes gave a gradual shift of azeotropic point according to the variation of solubility parameter and interaction parameter values between solute and polymer matrix. Regenerated cellulose film gave the best pervaporation performance in terms of IPA selectivity and durability. PVA showed high selectivity with reasonable flux. Poly(dimethylsiloxane), which is hydrophobic, was also studied as an aromatic selective membrane. The experiments were carried out over the entire range of 0–100% at 30°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3912–3921, 2003
Study of the properties and reliability of EMC packaging material
Authors: Chiu Hsien‐Tang , Chung Jung‐Sheng
Published: October 2003

Thermoplastic nylon powder with a low melting point was added to Biphenyl Epoxy to serve as a forming stress release agent that is intended to reduce the stress resulting from Epoxy Molding Compound (EMC). The purpose of this study was to explore the physical impact and effect on the formed object after adding nylon powder to Biphenyl Epoxy. Mechanical properties were explored through the Izod impact test and the three‐point bending test. Thermal Mechanical Analysis and Dynamic Mechanical Analysis were conducted to probe the coefficient of thermal expansion (CTE) and the glass transition temperature (Tg). The rate of water absorption was measured via a test of the pressure cook test (PCT), and insulation resistance was assessed through the insulating destruction experiment. The results indicate that adding nylon powder increases the fracture energy of the epoxy‐formed material; however, mechanical properties decreased slightly. TMA showed that the CTE (α1) decreased when nylon was added, and DMA revealed that heat resistance decreased slightly. The water absorption rate test and the PCT test showed that the rate of water absorption increased to a small extent, whereas the breakdown voltage (BDV) decreased slightly. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3928–3933, 2003
Relationship among phase morphology, oil resistance, and thermal aging properties in CPE/NR blends: effect of blending conditions
Authors: Sirisinha Chakrit , Saeoui Pongdhorn , Guaysomboon Jantagarn
Published: October 2003

The CPE/NR blends with blend ratio of 50/50% by weight were prepared with various blending conditions. The resistance to oil and thermal aging of the blends was investigated and correlated with phase morphology. The NR dispersed phase size in blends was found to decrease with increasing rotor speed up to 45 rpm and subsequently level off at higher rotor speeds. With increasing mixing time at a given rotor speed, NR dispersed phase size reached a minimum and increased again with a further increase in mixing time, caused by domain breakup and phase coalescence, respectively. In addition, the results revealed a strong relationship between NR phase size and resistances to oil as well as thermal aging, that is, the smaller the dispersed phase size, the higher the oil resistance and the thermal aging properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4038–4046, 2003
Synthesis and characterization of poly(urethane‐benzoxazine)/clay hybrid nanocomposites
Authors: Takeichi Tsutomu , Guo Yong
Published: October 2003

Poly(urethane‐benzoxazine)/clay hybrid nanocomposites (PU/Pa–OMMTs) were prepared from an in situ copolymerization of a polyurethane (PU) prepolymer and a monofunctional benzoxazine monomer, 3‐phenyl‐3,4‐dihydro‐2H‐1,3‐benzoxazine (Pa), in the presence of an organophilic montmorillonite (OMMT), by solvent method using DMAc. OMMT was made from cation‐exchange of Na‐montmorillonite (MMT) with dodecyl ammonium chloride. The formation of the exfoliated nanocomposite structures of PU/Pa‐OMMT was confirmed by XRD from the disappearance of the peak due to the basal diffraction of the layer‐structured clay found in both MMT and OMMT. DSC showed that, in the presence of OMMT, the curing temperature of PU/Pa lowered by ca. 60°C for the onset and ca. 20°C for the maximum. After curing at 190°C for 1 h, the exothermic peak on DSC disappeared. All the obtained films of PU/Pa–OMMT were deep yellow and transparent. As the content of OMMT increased, both the tensile modulus and strength of PU/Pa–OMMT films increased, while the elongation decreased. The characteristics of the PU/Pa–OMMT films changed from plastics to elastomers depending on OMMT content and PU/Pa ratio. PU/Pa–OMMT films also exhibited excellent resistance to the solvents such as tetrahydrofuran, N,N‐dimethylformamide and N‐methyl‐2‐pyrrolidinone. The thermal stability of PU/Pa were enhanced remarkably even with small amount of OMMT. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4075–4083, 2003
Low‐temperature carrier dyeing of poly(vinyl chloride) fibers with disperse dyes
Authors: Kim Ik Soo , Cho Han Moon , Koh Joonseok , Kim Jae Pil
Published: October 2003

The effects of various carriers on the color yield of poly(vinyl chloride) (PVC) filaments in a disperse dyeing system were investigated. The dyeability of disperse dyes on PVC fiber was improved using appropriate carriers. The enhancement of dye uptake imparted by carriers coincided with the reduction in glass‐transition temperature, which in turn coincided approximately with the similarity of the inorganic/organic ratio values between PVC fibers and carriers. The results clearly demonstrate that hydrophobic carriers function as diluents of PVC fiber, facilitating dye diffusion by increasing segmental mobility of the fiber. The dyed PVC filaments with disperse dyes showed reasonable levels of build‐up and color fastness properties in the carrier‐assisted dyeing. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3896–3904, 2003
Supercritical CO2 extraction of phthalate plasticizers from PVC
Authors: Shieh Yeong‐Tarng , Hsiao Tzu‐Ting , Lung Tzu‐I , Yang Huang‐Shung
Published: October 2003

Three common phthalates, namely, dioctyl phthalate, diisodecyl phthalate, and trioctyl trimellitate, were used as plasticizers for poly(vinyl chloride) (PVC) processing, and the extraction of these plasticizers were investigated using supercritical CO2 fluids. Factors affecting the extractions of these phthalates were focused. The molecular weight of phthalates was found to dominate the level of extraction of low temperatures, whereas the content of carbonyl groups in the phthalate was a determining factor for the level of extraction of high temperatures. Negligible extraction was observed below the critical pressure of CO2. For 32°C, the level of the extraction is insignificant below density of ca 0.7 g/cm3, above which the level of the extraction increases roughly linearly with increasing density. For temperatures above 32°C, the density of CO2 for apparent extractions decreased with increasing temperatures. The threshold density of CO2 for extractions was found to be independent of the amount of a given phthalate in PVC. Two extraction rates during the extraction could be determined, with a higher rate in the first hour followed by a lower rate later in the extraction for all three phthalates. The effects of the extractions of phthalates on the flexibility of PVC were also investigated as well as the effects of the extrusion conditions, which could lead to various degrees of plasticization of PVC, on the level of extractions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4032–4037, 2003