bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatal unintentional occupational poisonings by hydrofluoric acid in the U.S.
Authors: Blodgett David W. , Suruda Anthony J. , Crouch Barbara Insley
Published: October 2004

Background

Case reports have identified hydrofluoric acid (HF) as causing fatal work injury, and HF has both local and systemic toxicity. Surveillance for HF‐related mortality is problematic because of the lack of unique coding for this acid in hospital records and vital statistics.

Methods

We identified HF‐related fatal work injuries investigated by the Occupational Safety and Health Administration (OSHA) for 1984–94 from coding of Hazardous Substance 1460 (HF) and requested case investigation files under the Freedom of Information Act. We attempted to identify HF‐related deaths in the US for the same period through literature case reports, the Consumer Product Safety Commission, and the American Association of Poison Control Centers (AAPCC).

Results

For the 11 year period, OSHA investigated nine deaths in eight incidents which involved HF. Four deaths were from skin contact with concentrated HF, and five deaths involved both skin contact and inhalation of vapor. Unsafe work practices were factors in all of the deaths. Calcium chloride or gluconate was noted to have been administered to five of the nine victims. Calcium was administered 90 min after exposure to two victims, and more than 6 h after exposure to a third. We were able to establish that the regional poison control center had been contacted in regard to only one victim. For the period 1984–94, we were able to identify no additional deaths from CPSC reports, one additional death from AAPCC annual reports, and four other deaths from case reports in the medical literature.

Conclusions

For the period of this study, OSHA records identified the greatest number of HF‐related fatalities. The limited information in the records suggest that some victims did not receive appropriate medical care, nor was the regional poison center contacted regarding care. The full extent of health problems related to HF could be better quantified if usual surveillance sources, such as vital records, included unique coding for this acid. Am. J. Ind. Med. 40:215–220, 2001. © 2001 Wiley‐Liss, Inc.
Re: Occupational exposure to pesticides and pancreatic cancer. 2001. Ji B.‐T., Silverman D.T., Stewart P.A., Blair A., Swanson G.M., Baris D., Greenberg R.D., Hayes R., Brown L.M., Lillemoe K.D., Schoenberg J.B., Pottern L.M., Schwartz A.G., Hoover R. Am. J. Ind. Med. 39:92–99
Authors: Ji Bu‐Tian , Silverman Debra T. , Stewart Patricia A. , Blair Aaron , Hoover Robert
Published: October 2004

To the Editor:

In our recent paper describing associations of pancreatic cancer to pesticides, Table I presented JEM scores for selected occupations. We omitted several scores from the table, which indicated less variability across the study than was assessed. We have added all possible scores in Table I to reflect this variability. Also, several scores in the table may need further explanation. The supervisors, food and beverage preparation and food counter, fountain and related occupations had possible exposure to nonagricultural fungicides (i.e. disinfectants). Water and sewage treatment plant operators may handle herbicides to kill algae. Historically, textile mills and some dry cleaning operations applied insecticides to fabric. The subjects with jobs of mixing/blending machine operator/tender, or welder and cutter who were assigned pesticide exposures had worked in the chemical industry where pesticides may have been manufactured.

The omissions were only in the reported data and not in the original data, and thus did not affect the epidemiologic results or conclusions.
Development of a life events/icon calendar questionnaire to ascertain occupational histories and other characteristics of migrant farmworkers
Authors: Zahm Shelia Hoar , Colt Joanne S. , Engel Lawrence S. , Keifer Matthew C. , Alvarado Andrew J. , Burau Keith , Butterfield Patricia , Caldera Soledad , Cooper Sharon P. , Garcia Deliana , Hanis Craig , Hendrikson Edward , Heyer Nicholas , Hunt Linda M. , Krauska Michelle , MacNaughton Nancy , McDonnell Cheryl J. , Mills Paul K. , Mull L. Diane , Nordstrom David L. , Outterson Beth , Slesinger Doris P. , Smith Mary Ann , Stallones Lorann , Stephens Claudia , Sweeney Anne , Sweitzer Kimberley , Vernon Sally W. , Blair Aaron
Published: October 2004

Background

Specialized methods are necessary to collect data from migrant farmworkers for epidemiologic research.

Methods

We developed a questionnaire that collected lifetime occupational histories and other lifestyle risk factors via a life events/icon calendar, and administered the questionnaire to a convenience sample of 162 migrant farmworkers in nine areas of the U.S.

Results

The average duration of the interviews was about 1 h 30 min, with an average of 45 min for the work history section. The occupational histories covered a median of 27.6 years per person for men and 20.8 years per person for women. The median number of years spent in farm jobs was 11.3 for men and 5.8 for women. The median number of farm jobs (crop/task combination) per person was 59 among men and 27 among women. Many farmworkers performed the same crop/task combinations at multiple times throughout their lives, yielding a median of 13 unique farm jobs and 8 unique crops among men and 7 jobs and 5 crops among women.

Conclusions

The project demonstrated that it is feasible to collect detailed work histories and other risk factor data from farmworkers, documented the complexity of work histories encountered among farmworkers, and yielded recommendations for refining a questionnaire that will facilitate future epidemiologic research on farmworkers. Am. J. Ind. Med. 40:490–501, 2001. © 2001 Wiley‐Liss, Inc.
Determining the probability of pesticide exposures among migrant farmworkers: Results from a feasibility study†
Authors: Ward Mary H. , Prince Jacqueline R. , Stewart Patricia A. , Zahm Shelia Hoar
Published: October 2004

Background

Migrant and seasonal farmworkers are exposed to pesticides through their work with crops and livestock. Because workers are usually unaware of the pesticides applied, specific pesticide exposures cannot be determined by interviews. We conducted a study to determine the feasibility of identifying probable pesticide exposures based on work histories.

Methods

The study included 162 farm workers in seven states. Interviewers obtained a lifetime work history including the crops, tasks, months, and locations worked. We investigated the availability of survey data on pesticide use for crops and livestock in the seven pilot states. Probabilities of use for pesticide types (herbicides, insecticides, fungicides, etc.) and specific chemicals were calculated from the available data for two farm workers. The work histories were chosen to illustrate how the quality of the pesticide use information varied across crops, states, and years.

Results

For most vegetable and fruit crops there were regional pesticide use data in the late 1970s, no data in the 1980s, and state‐specific data every other year in the 1990s. Annual use surveys for cotton and potatoes began in the late 1980s. For a few crops, including asparagus, broccoli, lettuce, strawberries, plums, and Christmas trees, there were no federal data or data from the seven states before the 1990s.

Conclusions

We conclude that identifying probable pesticide exposures is feasible in some locations. However, the lack of pesticide use data before the 1990s for many crops will limit the quality of historic exposure assessment for most workers. Am. J. Ind. Med. 40:538–553, 2001. Published 2001 Wiley‐Liss, Inc.
Cancer incidence in the United Farmworkers of America (UFW), 1987–1997
Authors: Mills Paul K. , Kwong Sandy
Published: October 2004

Background

The purpose of this study was to evaluate cancer incidence in the membership a largely Hispanic farmworker labor union in California, the United Farmworkers of America (UFW) and to examine cancer‐site specific distributions as well as histology and stage of cancer at diagnosis in this group.

Methods

An electronic record linkage was conducted between a membership roster of the UFW and the database of the California Cancer Registry, the population‐based cancer registry in California for the years 1987–1997. Based upon the results of the linkage, morbidity odds ratios were calculated using the distribution of cancer in the California Hispanic population as the reference to determine if risk of specific cancers was higher or lower in the UFW. Time since first joining the union was evaluated, as was the proportional distribution of histologic subtypes and stage at diagnosis, again comparing the experience of the UFW membership to the California Hispanic population.

Results

Several types of cancer were elevated in the UFW membership in comparison to the California Hispanic population. Morbidity odds ratios and 95% confidence limits were elevated for leukemia (O.R. = 1.59: 95% C.I. = 1.07–2.37), stomach cancer (O.R. = 1.69: 95% C.I. = 1.24–2.27), uterine cervix cancer (O.R. = 1.63: 95% C.I. = 1.11–2.44) and uterine corpus cancer (O.R. = 1.68: 95% C.I. = 1.05–2.67). Brain cancer was also elevated although not significantly so (O.R. = 1.57: 95% C.I. = 0.96–2.53).

Conclusions

Risk of leukemia, stomach, cervix and uterine cancers was elevated in California farmworkers. The histologic distribution of leukemia and brain cancers within the UFW membership did not differ from the distribution in the general California population although small numbers of cancers in the UFW hindered interpretation of these results. Members of the UFW experienced later stage of disease at diagnosis in comparison to California Hispanics for most major cancer sites but not for breast cancer. Am. J. Ind. Med. 40:596–603, 2001. © 2001 Wiley‐Liss, Inc.
Proportionate mortality among US migrant and seasonal farmworkers in twenty‐four states†
Authors: Colt Joanne S. , Stallones Lorann , Cameron Lorraine L. , Dosemeci Mustafa , Zahm Shelia Hoar
Published: October 2004

Background

US migrant and seasonal farmworkers may be exposed to potentially carcinogenic pesticides and other agents. Little epidemiologic research has been conducted on this population.

Methods

We examined the proportionate mortality of 26,148 subjects (14,631 white men (WM), 7,299 nonwhite men (NM), 1,081 white women (WW), and 3,137 nonwhite women (NW)) who were identified as farmworkers on death certificates from 24 US states during 1984–1993.

Results

Farmworkers had significantly elevated proportionate mortality from injuries, tuberculosis, mental disorders, cerebrovascular disease, respiratory diseases, ulcers, hypertension (NW), and cirrhosis (NW). There was significantly reduced mortality from infectious diseases (other than tuberculosis), endocrine disorders, nervous system diseases, pneumoconioses, arteriosclerotic heart disease (WM), and all cancers combined. Proportionate cancer mortality analyses found excess cancers of the buccal cavity, larynx, esophagus, stomach, skin (NW), and cervix, and deficits for cancers of the colon, breast, kidney, pancreas (NW), and lymphohematopoietic system.

Conclusions

The excess deaths from injuries, respiratory disease, and stomach cancer, and the deficits of colon cancer and arteriosclerotic heart disease among farmworkers, are consistent with typical mortality patterns previously observed among farm owner/operators. The excess buccal, laryngeal, esophageal, and cervical cancers, and the deficits of breast cancer and lymphohematopoietic cancers have not generally been observed in studies of farm owner/operators. Am. J. Ind. Med. 40:604–611, 2001. Published 2001 Wiley‐Liss, Inc.
Positive association of dopamine D2 receptor polymorphism with bipolar affective disorder in a European multicenter association study of affective disorders
Authors: Massat Isabelle , Souery Daniel , Del‐Favero Jurgen , Van Gestel Sofie , Serretti Alessandro , Macciardi Fabio , Smeraldi Enrico , Kaneva Radka , Adolfsson Rolf , Nylander Peter O. , Blackwood Douglas , Muir Walter , Papadimitriou George N. , Dikeos Dimitris , Oruč Lilijana , Segman Ronnen H. , Ivezič Sladjana , Aschauer Harold , Ackenheil Manfred , Fuchshuber S. , Dam Henrik , Jakovljevič Miro , Peltonen Leena , Hilger Christiane , Hentges François , Staner Luc , Milanova Vihra , Jazin Elena , Lerer Bernard , Van Broeckhoven Christine , Mendlewicz Julien
Published: October 2004

Convincing evidence for a genetic component in the etiology of affective disorders (AD), including bipolar affective disorder (BPAD) and unipolar affective disorder (UPAD), is supported by traditional and molecular genetic studies. Most arguments lead to the complex inheritance hypothesis, suggesting that the mode of inheritance is probably not Mendelian but most likely oligogenic (or polygenic) and that the contribution of genes could be moderate or weak. The purpose of the present European multicenter study (13 centers) was to test the potential role in BPAD and UPAD of two candidate dopaminergic markers, DRD2 and DRD3, using a case‐control association design. The following samples were analyzed for DRD2: 358 BPAD/358 control (C) and 133 UPAD/ 133 C subjects, and for DRD3: 325 BPAD/ 325 C and 136 UPAD/136 C subjects. Patients and controls were individually matched for sex, age ( ± five years) and geographical origin. Evidence for significant association between BPAD and DRD2 emerged, with an over‐representation of genotype 5‐5 (P = 0.004) and allele 5 (P = 0.002) in BPAD cases compared to controls. No association was found for DRD2 in UPAD, and for DRD3 neither in BPAD or UPAD. Our results suggest that the DRD2 microsatellite may be in linkage disequilibrium with a nearby genetic variant involved in the susceptibility to BPAD. Our large European sample allowed for replicating of some previous reported positive findings obtained in other study populations. © 2002 Wiley‐Liss, Inc.
High prevalence of the G101W germline mutation in the CDKN2A (P16ink4a) gene in 62 Italian malignant melanoma families
Authors: Mantelli Michela , Barile Monica , Ciotti Paola , Ghiorzo Paola , Lantieri Francesca , Pastorino Lorenza , Catricalà Caterina , Torre Gabriella Della , Folco Ugo , Grammatico Paola , Padovani Laura , Pasini Barbara , Rovini Dario , Queirolo Paola , Rainero Maria Luisa , Santi Pier Luigi , Sertoli Roberto M. , Goldstein Alisa M. , Bianchi‐Scarrà Giovanna
Published: October 2004

CDKN2A germline mutation frequency estimates are commonly based on families with several melanoma cases. When we started counseling in a research setting on gene susceptibility analysis in northern and central Italy, however, we mostly found small families with few cases. Here we briefly characterize those kindred, estimate CDKN2A/CDK4 mutation test yields, and provide indications on the possibility of implementing formal DNA testing for melanoma‐prone families in Italy. In September 1995 we started genetic counseling in a research setting at our Medical Genetics Center. Screening for CDKN2A/CDK4 mutations was performed on families with two melanoma patients, one of whom was younger than 50 years at onset, the other complying with one of the following: 1) being a first‐degree relative, 2) having an additional relative with pancreatic cancer, or 3) having multiple primary melanomas. Sixty‐two of 67 (80%) melanoma cases met our criteria. Four previously described CDKN2A mutations (G101W, R24P, V126D, and N71S) were found in 21 of the 62 families (34%) with a high prevalence of G101W (18/21). The percentage of families with two melanoma cases/family harboring a mutation was low (7%, 2/27), but rose to 45% (9/20) if one of the melanoma patients carried multiple melanomas or if pancreatic cancer was present in that family. In the 15 families with three melanoma cases the presence of a mutation was higher (67%, 10/15) and reached 100% in the 4 families with four or more melanoma cases. Our results suggest that CDKN2A/CDK4 counseling‐based mutational analysis may be reasonably efficient also for families with two melanoma cases, if one patient carries multiple melanomas or if pancreatic cancer is present in the family. © 2002 Wiley‐Liss, Inc.
Apparent genotype–phenotype correlation in childhood, adolescent, and adult Chediak‐Higashi syndrome
Authors: Karim Mohammad A. , Suzuki Koji , Fukai Kazuyoshi , Oh Jangsuk , Nagle Deborah L. , Moore Karen J. , Barbosa Ernest , Falik‐Borenstein Tzipora , Filipovich Alexandra , Ishida Yasushi , Kivrikko Sirpa , Klein Christoph , Kreuz Friedmar , Levin Alex , Miyajima Hiroaki , Regueiro Jose R. , Russo Carolyn , Uyama Eiichiro , Vierimaa Outi , Spritz Richard A.
Published: October 2004

Chediak‐Higashi syndrome (CHS) is a rare autosomal recessive disorder characterized by severe immunologic defects, reduced pigmentation, bleeding tendency, and progressive neurological dysfunction. Most patients present in early childhood and die unless treated by bone marrow transplantation. About 10–15% of patients exhibit a much milder clinical phenotype and survive to adulthood, but develop progressive and often fatal neurological dysfunction. Very rare patients exhibit an intermediate adolescent CHS phenotype, presenting with severe infections in early childhood, but a milder course by adolescence, with no accelerated phase. Here, we describe the organization and genomic DNA sequence of theCHS1gene and mutation analysis of 21 unrelated patients with the childhood, adolescent, and adult forms of CHS. In patients with severe childhood CHS, we found only functionally null mutantCHS1alleles, whereas in patients with the adolescent and adult forms of CHS we also found missense mutant alleles that likely encode CHS1 polypeptides with partial function. Together, these results suggest an allelic genotype–phenotype relationship among the various clinical forms of CHS. © 2002 Wiley‐Liss, Inc.
Mutations in the dopamine β‐hydroxylase gene are associated with human norepinephrine deficiency
Authors: Kim Chun‐Hyung , Zabetian Cyrus P. , Cubells Joseph F. , Cho Sonhae , Biaggioni Italo , Cohen Bruce M. , Robertson David , Kim Kwang‐Soo
Published: October 2004

Norepinephrine (NE), a key neurotransmitter of the central and peripheral nervous systems, is synthesized by dopamine β‐hydroxylase (DBH) that catalyzes oxidation of dopamine (DA) to NE. NE deficiency is a congenital disorder of unknown etiology, in which affected patients suffer profound autonomic failure. Biochemical features of the syndrome include undetectable tissue and circulating levels of NE and epinephrine, elevated levels of DA, and undetectable levels of DBH. Here, we report identification of seven novel variants including four potentially pathogenic mutations in the human DBH gene (OMIM 223360) from analysis of two unrelated patients and their families. Both patients are compound heterozygotes for variants affecting expression of DBH protein. Each carries one copy of a T→C transversion in the splice donor site of DBH intron 1, creating a premature stop codon. In patient 1, there is a missense mutation in DBH exon 2. Patient 2 carries missense mutations in exons 1 and 6 residing in cis. We propose that NE deficiency is an autosomal recessive disorder resulting from heterogeneous molecular lesions at DBH. © 2002 Wiley‐Liss, Inc.
Frequencies of UDP‐glucuronosyltransferase 1 (UGT1A1) gene promoter polymorphisms among distinct ethnic groups from Brazil
Authors: Fertrin K.Y. , Gonçalves M.S. , Saad S.T.O. , Costa F.F.
Published: October 2004

A polymorphism in the promoter region of the UDP‐glucuronosyltransferase 1 (UGT1A) gene is associated with Gilbert syndrome (GS), a benign form of mild unconjugated hyperbilirubinemia. We genotyped 157 individuals from Brazil, comprising 71 Caucasians, 54 African‐derived subjects, and 32 Parakanã Indians. Frequencies of the alelle (TA)7 associated with GS found in this study were 0.324, 0.407, and 0.328, respectively. The genotype frequencies differed significantly between Caucasians and African‐derived individuals. The high frequencies of (TA)7 polymorphism among the three groups confirm previous data that this polymorphism is very ancient and appears to be distributed throughout the world. © 2002 Wiley‐Liss, Inc.
Germline engineering: The moral challenges
Authors: Engelhardt H. Tristram
Published: October 2004

Not only is the use of germline genetic engineering likely in the long run to be inevitable, there are also no convincing secular moral grounds to forbid this technology in principle. Instead, the general secular moral constraints on the use of germline genetic engineering are either procedural or without predetermined content. Nor can one develop a coherent distinction between eliminating disease and enhancing human abilities. At best, in secular morality one can establish the principle to proceed with care, though the invocation of the precautionary principle argues as much in favor of the development of germline genetic engineering as against its use. Because germline genetic engineering, by eliminating certain genetic defects, offers the prospect of decreasing human suffering and decreasing the use of prenatal diagnosis and abortion, there is an obligation, all else being equal, to change the human genome. In a post‐modern world, humans face the challenge of directing their own evolution, although they share no common understanding of human destiny and purpose. Such understandings, though available within religious contexts, are not available to secular bioethics. © 2002 Wiley‐Liss, Inc.
Mandibular variation among Chinese macaques
Authors: Pan Ruliang , Oxnard Charles , Milne Nick
Published: October 2004

In order to clarify the degree to which mandibular variation among Chinese macaques results from functional adaptation and phylogenetic inertia, 13 mandibular variables were analyzed by bivariate and multivariate techniques. The results indicate, not surprisingly, that the main differences in the mandible are associated with size. The study further implies that the variation between species is not closely associated with differences in functional adaptation even though the dietary and related differences are large compared to the situation in other macaques. The great variety in diet and related factors among Chinese macaques may not have yet resulted in a significant variation in the mandible. This may be because their radiation in Asia, though involving considerably greater differences in habitat, climate, and so on, has occurred more recently than for other macaque species in Southeast Asia. Mandibular variation between these species, therefore, is likely to be more closely tied to their immediate prior phylogenetic history. For example, the two stump‐tailed macaques are closely similar and are also closely similar to the Assam species. Function in the mandible in these species is quite different. The results, therefore, seem to support the hypothesis that these three macaque species should be placed in a single species‐group (sinica) as proposed by Delson [1980], Pan [1998], and Pan et al. [1998]. Am. J. Primatol. 56:99–115, 2002. © 2002 Wiley‐Liss, Inc.
Familiarity and dominance relations among female sooty mangabeys in the Taï National Park
Authors: Range Friederike , Noë Ronald
Published: October 2004

Dominance relationships of female sooty mangabeys have thus far been studied exclusively in captive groups. In captivity, adult females form a stable linear hierarchy as would be expected in species exhibiting strong contest competition. However, the same individuals do not exhibit other aspects of behavior that would be expected where contest competition occurs. For example, they show no kin‐based alliances leading to hierarchies in which the members of each matriline occupy adjacent ranks. The goal of this study was to provide the first data on dominance relationships of sooty mangabey females in their natural environment in the Taï National Park, Ivory Coast. In our study group, adult females formed a linear dominance hierarchy. Aggression over food increased in food patches, as would be expected for species that experience contest competition. Moreover, females formed highly differentiated social relationships, showing particular affinities with females of adjacent rank. Am. J. Primatol. 56:137–153, 2002. © 2002 Wiley‐Liss, Inc.
A novel tau mutation, S320F, causes a tauopathy with inclusions similar to those in Pick's disease
Authors: Rosso Sonia M. , Van Herpen Esther , Deelen Wout , Kamphorst Wouter , Severijnen Lies‐Anne , Willemsen Rob , Ravid Rivka , Niermeijer Martinus F. , Dooijes Dennis , Smith Michael J. , Goedert Michel , Heutink Peter , Van Swieten John C.
Published: October 2004

Mutations in the tau gene cause familial frontotemporal dementia and parkinsonism linked to chromosome 17. In this article, we describe a novel missense mutation, S320F, in the tau gene in a family with presenile dementia. To our knowledge, it is the first mutation to be described in exon 11 of tau. The proband died at age 53 years, after a disease duration of 15 years, and autopsy revealed a neuropathological picture similar to Pick's disease. Recombinant tau protein with the S320F mutation showed a greatly reduced ability to promote microtubule assembly.
Studies on surface energetics of glass fabrics in an unsaturated polyester matrix system: Effect of sizing treatment on glass fabrics
Authors: Park Soo‐Jin , Kim Taek‐Jin
Published: October 2004

The surfaces of glass fibers were sized by polyvinyl alcohol (PVA), polyester, and epoxy resin types in order to improve the mechanical interfacial properties of fibers in the unsaturated polyester matrix. The surface energetics of the glass fibers sized were investigated in terms of contact angle measurements using the wicking method based on the Washburn equation, with deionized water and diiodomethane as the wetting liquids. In addition, the mechanical behaviors of the composites were studied in the context of the interlaminar shear strength (ILSS), critical stress intensity factor (KIC), and flexural measurements. Different evolutions of the London dispersive and specific (or polar) components of the surface free energy of glass fibers were observed after different sizing treatments. The experimental result of the total surface free energies calculated from the sum of their two components showed the highest value in the epoxy‐sized glass fibers. From the measurements of mechanical properties of composites, it was observed that the sizing treatment on fibers could improve the fiber–matrix interfacial adhesion, resulting in improved final mechanical behaviors, a result of the effect of the enhanced total surface free energy of glass fibers in a composite system. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1439–1445, 2001
Acrylate‐based liquid rubber as impact modifier for epoxy resin
Authors: Ratna D. , Banthia A. K. , Deb P. C.
Published: October 2004

Carboxyl‐terminated poly(2‐ethyl hexyl acrylate) (CTPEHA) having various molecular weights were synthesized by bulk polymerization in the form of liquid rubber. The liquid rubbers (LR‐1 to LR‐4) were characterized by 13C‐NMR spectroscopic analysis, nonaqueous titration, and vapor‐pressure osmometry (VPO). The liquid rubber having the lowest molecular weight (M̄n = 3600) was prereacted with the epoxy resin and the modified epoxy networks were made by curing with an ambient temperature curing agent. The modified epoxy networks containing different concentrations of CTPEHA were evaluated with respect to their thermal and impact properties. The optimum properties were obtained at about 10–15 phr of CTPEHA concentration (phr stands for parts per hundred parts of epoxy resin). Fracture surface analysis by scanning electron microscopy (SEM) indicated the presence of a two‐phase microstructure. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1792–1801, 2001
Copolymerization of N‐substituted maleimide with alkyl acrylate and its industrial applications
Authors: Thamizharasi S. , Reddy B. S. R.
Published: October 2004

A series of new copolymers with desired thermal stability and mechanical properties for applications in leather industry were synthesized from various substituted maleimides and alkyl acrylates. Polymerization was carried out by a free‐radical polymerization using benzoyl peroxide (BPO) as initiator. The monomers and polymers synthesized were characterized by elemental analysis, IR, and nuclear magnetic resonance (NMR). Interestingly, these polymers were soluble in common organic solvents. Copolymer composition and reactivity ratios were determined by 1H‐NMR spectra. The molecular weights of the polymers were determined by gel permeation chromatography. The homo‐ and copolymer of maleimide showed single‐stage decomposition (ranging from 300–580°C). The initial decomposition temperatures of poly[N‐(phenyl)maleimide] [poly(PM)], poly[N‐4‐(methylphenyl)maleimide] [poly(MPM)] and poly[N‐3‐(chlorophenyl)maleimide] [poly(CPM)] were higher compared to those of the copolymers. Heat‐resistant adhesives such as blends of epoxy resin with phenyl‐substituted maleimide‐co‐glycidyl methacrylate copolymers with improved adhesion property were developed. Different adhesive formulations of these copolymaleimides were prepared by curing with diethanolamine at two different temperatures (30°C and 60°C). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1870–1879, 2001
The effects of p‐butoxyphenylcyclohexyl‐phosphinic acid on the properties of PC based on Bisphenol A
Authors: Ozden S. , Shaov A. H. , Charayev A. M. , Gurdaliyev X. X
Published: October 2004

A polymer stabilizer, p‐butoxyphenylcyclohexyl‐phosphinic acid, was introduced into an industrial polymer, a Bisphenol A‐based polycarbonate, and the effects of this stabilizer on the mechanical and thermal properties were investigated. The mechanical properties were improved with small amount of stabilizers, while thermal properties were not effected significantly. For higher contents of stabilizer, both thermal and mechanical properties were deteriorated. This deterioration was caused by the increase of molecular distance between the chains, which lead to the reduction of polar forces and an increase in the free volume of the polymer. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2113–2119, 2001
Sorption properties of poly(styrene‐co‐divinylbenzene) amine functionalized weak resin
Authors: Rivas Bernabé L. , Pooley S. Amalia , Maturana Hernán A. , Villegas Sandra
Published: October 2004

The poly(styrene‐co‐divinylbenzene) amine functionalized weak resin was studied as adsorbent of heavy metal ions from an aqueous solution by using the Batch equilibrium procedure. The resin adsorbed Hg(II) 56% (0.56 mEq/g) at pH 2, and 45% (1.13 mEq/g) of U(VI), 38% (0.36 mEq/g) of Pb(II) at pH 5 from an aqueous solution containing 1 g/L of each metal ion. It did not adsorb Cd(II), Zn(II). The equilibrium time was achieved during the first hour. The maximum load capacity for Hg(II) was 0.8 mEq/g (75 mg)/g dry resin. It is possible to recover around 60% of the resin after the treatment with 1–4 M HClO4 and HNO3 of the loaded Hg(II) resin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2123–2127, 2001
Dielectric properties and ferroelectric behavior of poly(vinylidene fluoride‐trifluoroethylene) 50/50 copolymer ultrathin films
Authors: Xu Haisheng
Published: October 2004

Ultrathin films of poly(vinylidene fluoride‐trifluoroethylene) copolymer [P(VDF‐TrFE), with a content (mol %) ratio of 50/50 VDF/TrFE] were fabricated on silicon wafers covered with platinum by a spin‐coating technique, ranging in thickness from 20 nm to 1 μm. The effect of thickness on dielectric properties and polarization behavior was investigated. A critical thickness was found to be about 0.1 μm. An abrupt drop of dielectric constant was observed, although there is no significant change in dielectric loss at this thickness. Square and symmetric hysteresis loops were obtained in films thicker than 0.1 μm. However, for films thinner than 0.1 μm, fewer square hysteresis loops were observed. SEM and X‐ray results demonstrate that the effect of thickness on dielectric and ferroelectric properties could be explained by the changes of crystal structure in these films. In addition, the effects of irradiation on dielectric property and polarization response for ultrathin P(VDF‐TrFE) films were also presented. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2259–2266, 2001
Miscibility of block copolymers of poly(ε‐caprolactone) and poly(ethylene glycol) with poly(3‐hydroxybutyrate) as well as the compatibilizing effect of these copolymers in blends of poly(ε‐caprolactone) and poly(3‐hydroxybutyrate)
Authors: Shuai Xintao , He Yong , Na Yang‐Ho , Inoue Yoshio
Published: October 2004

Atactic poly(3‐hydroxybutyrate) (a‐PHB) and block copolymers of poly(ethylene glycol) (PEG) with poly(ε‐caprolactone) (PCL‐b‐PEG) were synthesized through anionic polymerization and coordination polymerization, respectively. As demonstrated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) measurements, both chemosynthesized a‐PHB and biosynthesized isotactic PHB (i‐PHB) are miscible with the PEG segment phase of PCL‐b‐PEGs. However, there is no evidence showing miscibility between both PHBs and the PCL segment phase of the copolymer even though PCL has been block‐copolymerized with PEG. Based on these results, PCL‐b‐PEG was added, as a compatibilizer, to both the PCL/a‐PHB blends and the PCL i‐PHB blends. The blend films were obtained through the evaporation of chloroform solutions of mixed components. Excitingly, the improvement in mechanical properties of PCL/PHB blends was achieved as anticipated initially upon the addition of PCL‐b‐PEG. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2600–2608, 2001
High molecular weight tail and long‐chain branching in low‐density polyethylenes
Authors: Beer F. , Capaccio G. , Rose L. J.
Published: October 2004

The composition of the high molecular weight tail in branched low‐density polyethylenes made by both tubular and autoclave reactors was studied in detail using size‐exclusion chromatography (SEC) coupled with a viscosity detector (VD) and a two‐angle light‐scattering detector (LSD). The detection of a second peak at very small elution volumes in the light‐scattering chromatogram but not in the refractive index chromatogram and viscosity chromatogram is due to high molecular weight species. It is also indicative of a change in the long‐chain branching distribution. It was found that the intrinsic viscosity contraction factor g′ scales with the radius of the gyration contraction factor, g, with the exponent, ε, having a value in the range 0.4–1.4. Furthermore, ε shows significant molar mass dependence. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2815–2822, 2001
Sulfonation of styrene‐grafted poly(vinylidene fluoride) films
Authors: Walsby Nadia , Paronen Mikael , Juhanoja Jyrkki , Sundholm Franciska
Published: October 2004

Electron‐beam irradiated and styrene‐grafted poly(vinylidene fluoride) films are sulfonated with chlorosulfonic acid in dichloroethane under various conditions. The impact of the reaction time, the concentration of the sulfonating agent, and the reaction temperature on the properties of the sulfonated film is examined. Sulfonation proceeds via a reaction front mechanism. Sulfonation of surface‐grafted films is incomplete at room temperature. The number of side reactions taking place appears to be linearly dependent on the concentration of the sulfonation solution. Dimensional changes suggest that sulfone crosslinking is significant at higher concentrations. This reduces the ion‐exchange capacity and proton conductivity of the films but increases the resistance to oxidation in a H2O2 solution. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1572–1580, 2001
Synthesis and characterization of novel block copolymer from trans‐4‐hydroxy‐L‐proline and poly(ethylene glycol)
Authors: Lee Ren‐Shen , Yang Jen‐Ming
Published: October 2004

A series of novel ABA‐type block copolymers were synthesized by polymerization of trans‐4‐hydroxy‐L‐proline (HyP) in the presence of various molecular weight poly(ethylene glycol)s (PEGs), a bifunctional OH‐terminated PEG using stannous octoate as catalyst. The optimal reaction conditions for the synthesis of the copolymers were obtained with 5 wt % stannous octoate at 140°C under vacuum (20 mmHg) for 24 h. The synthesized copolymers were characterized by IR spectroohotometry, proton nuclear magnetic resonance, differential scanning calorimetry, and Ubbelohde viscometer. The glass transition temperature (Tg) of the copolymers shifted to significantly higher temperature with increasing the number average degree of polymerization and HyP/PEO molar ratio. In contrast, the melting temperature (Tm) decreased with increasing the HyP/PEO molar ratio. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1581–1587, 2001
Characterization of branched polymers by size exclusion chromatography coupled with multiangle light scattering detector. I. Size exclusion chromatography elution behavior of branched polymers
Authors: Podzimek S. , Vlcek T. , Johann C.
Published: October 2004

The elution behavior of branched macromolecules during their separation by size exclusion chromatography (SEC) was studied. The elution behavior of branched polymers was investigated using samples of randomly branched polystyrene and star branched poly(benzyl methacrylate) of different levels of branching by means of a SEC chromatograph coupled with a multiangle light scattering detector. Abnormal SEC elution behavior was found to be typical for highly branched polymers. After a normal elution at small elution volumes the molar mass and root mean square radius of the eluting molecules increased with increasing elution volume. Several SEC experiments were carried out to find explanation for this effect and SEC separation was compared with the separation by thermal field flow fractionation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1588–1594, 2001
Application of DMAEMA‐grafted expanded PTFE films to positively charged ultrafiltration membranes and their electrostatic sieve separation properties
Authors: Yamada Kazunori , Gondo Takeshi , Hirata Mitsuo
Published: October 2004

A study was done of the ultrafiltration properties of expanded polytetrafluoroethylene (ePTFE) films with two average pore sizes, 0.5 and 3.0 μm, grafted with 2‐(dimethylamino)ethyl methacrylate (DMAEMA)—grafted 0.5‐ePTFE and grafted 3.0‐ePTFE—using dextran (Dxt) and quaternized dextran (qDxt) in water and in buffer solutions with a pH in the range of 4–10. The water permeability was found to be proportional to the operating pressure below 2.0 kgf/cm2. Grafted 0.5‐ePTFE films apparently had a higher rejection than did the grafted 3.0‐ePTFE films, and the cutoff value for grafted 0.5‐ePTFE films decreased with an increase in the grafted amount. The apparent rejection of Dxt and qDxt increased with a decrease in the pH value, and the apparent rejection of qDxt was higher than that of Dxt when the pH was in the range of 4–8 because of an electrostatically repulsive interaction between positively charged grafted PDMAEMA chains and qDxt molecules. For grafted 0.5‐ePTFE films, 40KDxt was selectively separated from the 40KDxt/250KDxt mixture systems in water and from the 40KDxt/40KqDxt mixture systems at pH 6 using the difference in their apparent rejection; the separation factors in both systems increased with the grafted amount. These results indicate that grafted ePTFE films are applicable to positively charged ultrafiltration membranes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1595–1604, 2001
Influence of extenders on thermal and elastic properties of segmented copolyetheresteraramides
Authors: Niesten M. C. E. J. , Bosch H. , Gaymans R. J.
Published: October 2004

Copolyetheresteramides with bisesterdiamide units of a uniform length were synthesized in the current study, and the dynamic mechanical and elastic properties of the copolymers produced were studied. Diols are used to extend the length of uniform bisesterdiamide hard segments. Extenders have a twofold effect: increasing the lamellar thickness of the bisesterdiamide crystals and having the ability to independently adjust the ratio between the hard and soft segment. It was found that polymers containing 1,12‐dodecanediol as an extender possess a multiphase structure. Two glass‐transition temperatures (Tg) were observed along with a very broad melting transition. The Tg at about −70°C was found to originate from the amorphous polyether phase, the Tg at about 140–175°C was attributed to a glassy aramid‐1,12‐dodecanediol phase. The broad melting transition was caused by the presence of the wide variety of lamellar sizes. This multiphase morphology is probably results from the liquid–liquid demixing of an aramid–polyether and from the aramid‐extender phase. Polymers containing 1,12‐dodecanediol and 13 wt % aramid had an improved elasticity compared to similar polymers without an extender. It is thought this is the result of large isolated, spherically shaped domains become less plastically deformed than the crystalline network of thin lamellae. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1605–1613, 2001
Aberrations in confocal spectroscopy of polymeric materials: Erroneous thicknesses and intensities, and loss of resolution
Authors: Michielsen Stephen
Published: October 2004

Confocal fluorescence and Raman microscopy are becoming important characterization methods in polymers, especially for blends and films. However, caution must be used in analyzing the data because of the spherical aberration introduced into the illumination and collection of light caused by a mismatch in the indices of refraction of the sample and the design of the microscope objective. In many cases, the measured shape of the region under examination and the measured intensities are rendered invalid because of this aberration. Simultaneously, the axial resolution is degraded because the central light rays and the extreme rays have different focal points. It is shown that the loss of axial resolution can be minimized and the loss in intensity can be either reduced or accounted for. The error in location within the sample and, hence, the shape can be easily corrected. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1662–1669, 2001
Dynamic light‐scattering characterization of the molecular weight distribution of unfractionated polyimide
Authors: Siddiq Mohammad , Wu Chi
Published: October 2004

Using a developed laser light‐scattering (LLS) procedure, we accomplished the characterization of an unfractionated polyimide (UPI) in CHCl3 at 25°C. The Laplace inversion of precisely measured intensity–intensity time correlation function from dynamic LLS leads us first to an estimate of the characteristic line‐width distribution G(Γ), and then to the translational diffusion coefficient distribution G(D). By using a previously established calibration of D (cm2/s) = 3.53 × 10−4 M−0.579, we were able to convert G(D) into a molecular weight distribution. The weight‐average molecular weight Mw, calculated from the molecular weight distribution, agrees well with that directly measured in static LLS. Our results indicate that both the calibration and LLS procedure used in this study are ready to be applied as a routine method for the characterization of the molecular weight distribution of polyimide. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1670–1674, 2001
Kinetics of miniemulsion polymerization of vinyl acetate with nonionic and anionic surfactants
Authors: Wu X. Q. , Schork F. J.
Published: October 2004

The kinetics of miniemulsion polymerization of vinyl acetate, in which nonionic surfactant, Brij‐35 [polyoxyethylene(23) lauryl ether], and hexadecane were used, was investigated. For comparison, experiments were also carried out using an anionic surfactant (sodium lauryl sulfate). The results show that, for all experiments, both distributions for the particle size of the latices and the molecular weight of polymers were unimodal. The effects of surfactant and initiator levels on the particle number and the polymerization rate were studied. For the system using Brij‐35, the power orders for the dependence of particle number on surfactant and initiator concentrations were 1.33 and 0.68, respectively. The polymerization rate was proportional to the 0.38 power of surfactant level and the 0.84 power of initiator concentration. The hydration layer outside the monomer‐swollen particles in the system of nonionic surfactant may exert a retardation effect on the entry of oligomeric radicals into the particles. The result of GPC analysis indicates that the surfactant concentration inversely affects the molecular weight. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1691–1699, 2001
DSC and DMA studies on silane‐grafted and water‐crosslinked LDPE/LLDPE blends
Authors: Shieh Yeong‐Tarng , Chuang Hui‐Chun
Published: October 2004

Effects of silane grafting and water crosslinking reactions on crystallizations, melting behaviors, and dynamic mechanical properties of the LDPE/LLDPE blends are investigated using DSC and DMA. From DSC data, cocrystallization of LDPE and LLDPE does not occur, but cocrosslinking of these two polymers is evidenced at the experimental temperature of 100°C, a temperature lower than melting temperatures of both polymers. The water crosslinking reactions of the LLDPE‐rich blends enable development of a new phase having a melting endotherm in between that of LDPE and LLDPE. From the thermal fractionation data, interaction between LDPE and LLDPE is observed, and compatibilization of the blends can be achieved by the crosslinking reactions. From DMA data, the storage moduli of the blends are not found to be consistent with their degrees of crosslinking. The storage moduli of the blends are not simply determined by the degree of crosslinking but determined by very complicated but unclear factors. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1808–1816, 2001
Oxidative copolymers of aniline with o‐toluidine: Their structure and thermal properties
Authors: Huang Mei‐Rong , Li Xin‐Gui , Yang Yu‐Liang , Wang Xue‐Song , Yan Deyue
Published: October 2004

Chemically oxidative polymerization of aniline and o‐toluidine (OT) with 6 molar ratios was performed using ammonium persulfate as an oxidant in a HCl medium at −18°C. It was observed that the copolymers were not regularly dependent on the monomer ratio for yield and intrinsic viscosity. The resulting copolymers were characterized by Fourier transform IR spectroscopy, 1H‐NMR spectroscopy, wide‐angle X‐ray diffraction, differential scanning calorimetry, and several thermogravimetry methods. The results showed that the actual content of the OT unit in the copolymers was much higher than the feed content of the OT unit. Given the same reaction conditions, o‐toluidine showed a larger tendency toward homopolymerization rather than toward copolymerization with aniline. The copolymers were amorphous and exhibited thermal decomposition temperatures higher than 440°C and a char yield larger than 39 wt % at 900°C in nitrogen. The activation energy of thermal decomposition for the copolymers was 40–244 kJ/mol in nitrogen and 32 kJ/mol in air, respectively. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1838–1847, 2001