bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment and prognosis for synchronous multifocal osteosarcoma in 42 patients
Authors: Bacci G. , Fabbri N. , Balladelli A. , Forni C. , Palmerini E. , Picci P.
Published: July 2006

Between 1986 and 2002, 42 patients with synchronous multifocal osteosarcoma were treated with two different protocols of neoadjuvant chemotherapy. When feasible, the primary and secondary tumours were excised as a combined procedure.

After initial chemotherapy 26 patients were excluded from simultaneous excision of all their secondary bone lesions as their disease was too advanced. In 12 patients only isolated excision of the primary lesion was possible. For 16 patients simultaneous operations were conducted to excise the primary and secondary lesions. This involved two supplementary sites in 15 patients and four additional sites in one patient. Of these, 15 attained remission but 12 relapsed and died (11 within two years). Three patients remained disease-free at five, six and 17 years. The histological response to pre-operative chemotherapy of the primary and secondary lesions was concordant in 13 of the 16 patients who underwent simultaneous operations at more than one site.

The prognosis for synchronous multifocal osteosarcoma remains poor despite combined chemotherapy and surgery. The homogeneous histological responses in a large proportion of the primary and secondary lesions implies that synchronous multifocal osteosarcoma tumours are not multicentric in origin, but probably represent bone-to-bone metastases from a single tumour.
Attacking the Obesity Epidemic: The Potential Health Benefits of Providing Nutrition Information in Restaurants
Authors: Burton Scot , Creyer Elizabeth H. , Kees Jeremy , Huggins Kyle
Published: July 2006

Objectives. Requiring restaurants to present nutrition information on menus is under consideration as a potential way to slow the increasing prevalence of obesity. Using a survey methodology, we examined how accurately consumers estimate the nutrient content of typical restaurant meals. Based on these results, we then conducted an experiment to address how the provision of nutrition information on menus influences purchase intentions and reported preferences.

Methods. For both the survey and experiment, data were analyzed using analysis of variance techniques.

Results. Survey results showed that levels of calories, fat, and saturated fat in less-healthful restaurant items were significantly underestimated by consumers. Actual fat and saturated fat levels were twice consumers’ estimates and calories approached 2 times more than what consumers expected. In the subsequent experiment, for items for which levels of calories, fat, and saturated fat substantially exceeded consumers’ expectations, the provision of nutrition information had a significant influence on product attitude, purchase intention, and choice.

Conclusions. Most consumers are unaware of the high levels of calories, fat, saturated fat, and sodium found in many menu items. Provision of nutrition information on restaurant menus could potentially have a positive impact on public health by reducing the consumption of less-healthful foods.
The Answer to Diabetes Prevention: Science, Surgery, Service Delivery, or Social Policy?
Authors: Colagiuri Ruth , Colagiuri Stephen , Yach Derek , Pramming Stig
Published: July 2006

The diabetes and obesity epidemics are closely intertwined. International randomized controlled trials demonstrate that, in high-risk individuals, type 2 diabetes can be prevented or at least delayed through lifestyle modification and, to a lesser degree, medication. We explored the relative roles of science, surgery, service delivery, and social policy in preventing diabetes.

Although it is clear that there is a role for all, diabetes is a complex problem that demands commitment across a range of government and nongovernment agencies to be effectively controlled. Accordingly, we argue that social policy is the key to achieving and sustaining social and physical environments required to achieve widespread reductions in both the incidence and prevalence of diabetes.
Understanding the Determinants of Health for People With Type 2 Diabetes
Authors: Maddigan Sheri L. , Feeny David H. , Majumdar Sumit R. , Farris Karen B. , Johnson Jeffrey A.
Published: July 2006

Objective. We assessed which of a broad range of determinants of health are most strongly associated with health-related quality of life (HRQL) among people with type 2 diabetes.

Methods. Our analysis included respondents from the Canadian Community Health Survey Cycle 1.1 (2000–2001) who were aged 18 years and older and who were identified as having type 2 diabetes. We used regression analyses to assess the associations between the Health Utilities Index Mark 3 and determinants of health.

Results. Comorbidities had the largest impact on HRQL, with stroke (−0.11; 95% confidence interval [CI] = −0.17, −0.06) and depression (−0.11; 95% CI = −0.15, −0.06) being associated with the largest deficits. Large differences in HRQL were observed for 2 markers of socioeconomic status: social assistance (−0.07; 95% CI=−0.12, −0.03) and food insecurity (−0.07; 95% CI=−0.10, −0.04). Stress, physical activity, and sense of belonging also were important determinants. Overall, 36% of the variance in the Health Utilities Index Mark 3 was explained.

Conclusion. Social and environmental factors are important, but comorbidities have the largest impact on HRQL among people with type 2 diabetes.
Gender and the Burden of Disease Attributable to Obesity
Authors: Muennig Peter , Lubetkin Erica , Jia Haomiao , Franks Peter
Published: July 2006

Objectives. We estimated the burden of disease in the United States attributable to obesity by gender, with life expectancy, quality-adjusted life expectancy, years of life lost annually, and quality-adjusted life years lost annually as outcome measures.

Methods. We obtained burden of disease estimates for adults falling into the following body-mass index categories: normal weight (23 to <25), overweight (25 to <30), and obese (≥ 30). We analyzed the 2000 Medical Expenditure Panel Survey to obtain health-related quality-of-life scores and the 1990–1992 National Health Interview Survey linked to National Death Index data through the end of 1995 for mortality.

Results. Overweight men and women lost 270 000 and 1.8 million quality-adjusted life years, respectively, relative to their normal-weight counterparts. Obese men and women lost 1.9 million and 3.4 million quality-adjusted life years, respectively, per year. Much of the burden of disease among overweight and obese women arose from lower health-related quality of life and late life mortality.

Conclusions. Relative to men, women suffer a disproportionate burden of disease attributable to overweight and obesity, mostly because of differences in health-related quality of life.
Healthier Choices and Increased Participation in a Middle School Lunch Program: Effects of Nutrition Policy Changes in San Francisco
Authors: Wojcicki Janet M. , Heyman Melvin B.
Published: July 2006

In order to address overall nutritional health, including increases in numbers of overweight children and adolescents, the San Francisco Unified School District implemented a progressive nutrition policy beginning in August 2003. We review this policy and focus on its impact on school and district revenues and students’ participation in the federally subsidized school lunch program.

We examined changes in menu items and the consequent effects of these changes on student eating patterns and school revenues at Aptos Middle School in San Francisco. This case study and additional district data show that provision of healthy menu options led to increased student participation in the federal school lunch program.
Education and Diabetes in a Racially and Ethnically Diverse Population
Authors: Borrell Luisa N. , Dallo Florence J. , White Kellee
Published: July 2006

Objectives. We used data from the National Health Interview Survey (1997–2002) to examine the association between education and the prevalence of diabetes in US adults and whether this relation differs by race/ethnicity.

Methods. The analyses were limited to non-Hispanic Blacks, non-Hispanic Whites, and Hispanics. SUDAAN was used to account for the complex sampling design.

Results. Educational attainment was inversely associated with the prevalence of diabetes. Individuals with less than a high-school diploma were 1.6 (95% confidence interval [CI]=1.4, 1.8) times more likely to have diabetes than those with at least a bachelor’s degree. Whites and Hispanics exhibited a significant relation between diabetes and having less than a high-school education (odds ratio [OR]=1.7; 95% CI=1.5, 2.0; and OR=1.6; 95% CI=1.1, 2.3, respectively). In addition, the odds of having diabetes was stronger for women (OR=1.9; 95% CI=1.6, 2.4) than for men (OR=1.4; 95% CI=1.1, 1.6)

Conclusions. Educational attainment was inversely associated with diabetes prevalence among Whites, Hispanics, and women but not among Blacks. Education may have a different effect on diabetes health among different racial/ethnic groups.
Assembling a Global Vaccine Development Pipeline for Infectious Diseases in the Developing World
Authors: Serdobova Irina , Kieny Marie-Paule
Published: July 2006

Commercial realities have drastically reduced private investment in the development of new public health tools, but increased awareness of this situation has resulted in the emergence of a variety of research-based, nonprofit organizations. We reviewed current vaccine developments and developed a framework for efficient research and development investments in this area.

We have identified several key “push” and “pull” forces within the vaccine research and product development environment and have examined their impacts on the process. These forces affect the global vaccine pipeline, which is composed of all individual vaccine initiatives and global partnerships (i.e., stakeholders), All of these research and development stakeholders must work together to establish and promote a global, sustainable research and development pipeline that delivers optimal vaccines and immunization technologies.
Low Birthweight and Asthma Among Young Urban Children
Authors: Nepomnyaschy Lenna , Reichman Nancy E.
Published: July 2006

Objectives. We assessed whether the association between low birthweight and early childhood asthma can be explained by an extensive set of individual- and neighborhood-level measures.

Methods. A population-based sample of children born in large US cities during 1998–2000 was followed from birth to age 3 years (N=1803). Associations between low birthweight and asthma diagnosis at age 3 years were estimated using multilevel models. Prenatal medical risk factors and behaviors, demographic and socioeconomic characteristics, and neighborhood characteristics were controlled.

Results. Low-birthweight children were twice as likely as normal birthweight children to have an asthma diagnosis (34% vs 18%). The fully adjusted association (OR= 2.36; P<.001) was very similar to the unadjusted association (OR= 2.48; P<.001). Rates of renter-occupied housing and vacancies at the census tract–level were strong independent predictors of childhood asthma.

Conclusions. Very little of the association between low birthweight and asthma at age 3 can be explained by an extensive set of demographic, socioeconomic, medical, behavioral, and neighborhood characteristics. Associations between neighborhood housing characteristics and asthma diagnosis in early childhood need to be further explored.
Television Viewing and Pedometer-Determined Physical Activity Among Multiethnic Residents of Low-Income Housing
Authors: Bennett Gary G. , Wolin Kathleen Y. , Viswanath K. , Askew Sandy , Puleo Elaine , Emmons Karen M.
Published: July 2006

Objectives. We evaluated the association between television viewing and pedometer-determined physical activity among predominantly racial/ethnic minority residents of low-income housing in metropolitan Boston in 2005.

Methods. We used mixed models to analyze the association between reported hours of television viewing and pedometer-determined steps per day among 486 adults. We also examined whether television viewing was associated with the achievement of 10000 steps per day.

Results. There was a mean 3.6 hours of average daily television watching. In multivariable analyses, each hour of television viewing on an average day was associated with 144 (95% confidence interval [CI]= −276, −12) fewer steps per day and a decreased likelihood of accumulating 10 000 steps per day (odds ratio [OR]=0.84; 95% CI=0.71, 0.99). Weekday and weekend television viewing were each also associated with fewer steps per day.

Conclusions. Average daily television viewing was associated with reductions in total pedometer-determined physical activity levels (approximately 520 steps per day) in this lower-income sample. As part of a comprehensive physical activity promotion plan, recommendations to reduce television viewing should be made.
Gender Differences in Grief Reactions following the Death of a Parent
Authors: Lawrence Elizabeth , Jeglic Elizabeth L. , Matthews Laura T. , Pepper Carolyn M.
Published: July 2006

This study examined gender differences in psychological functioning in a sample of college students who lost a parent to death. Male and female students ( n = 65) who had a parent that had died were asked to complete a series of self report questionnaires to assess psychological distress, feelings of grief and bereavement, and coping strategies. Overall, no gender differences were found between bereaved students on measures of psychological distress. However an avoidant coping style was related to symptoms of depression in females, but not in males. Students who lost a mother were more likely to report symptoms of depression, hopelessness, and suicidal ideation as compared to students who lost a father. Future research implications and the clinical importance of these findings are discussed.
Experiences of Social Networks Supporting Traumatically Bereaved
Authors: Dyregrov Kari
Published: July 2006

The importance of social support in reducing the impact of sudden loss on grief symptomatology and facilitating psychological adaptation has often been stressed by theorists. However, the accounts of family members, friends and work colleagues who actually have supported traumatically bereaved groups have seldom been addressed. This article describes how social networks have supported parents who lost their offspring due to traumatic deaths (suicide or SIDS) and how it has impacted them. Finally, their advice to future networks is presented. The networks' experiences and opinions are explored through qualitative and quantitative research methods. Data was gathered during 2004, through questionnaires from 100 social network members, and 21 focus group interviews ( N = 69). The networks elaborate on various aspects of strain and growth from the experience, give important advice to future networks, and stress the importance of some professional guidance to prevent them from “burn-out” in this particular straining relationship.
Mental Distress and Family Functioning among Married Parents Bereaved by a Child's Sudden Death
Authors: Lohan Janet A. , Murphy Shirley A.
Published: July 2006

A child's sudden death is a highly traumatic event for parents and siblings. This study examined mental distress and family functioning in a sample of 32 married couples that were part of a larger study of parents whose adolescent or young adult children had died suddenly by accident, suicide, or homicide. Parents were recruited into the study 4–7 months after the child's death. Cohesion, flexibility, and mental distress were the variables of interest, and individual scores were compared at three time points: baseline, 6 and 18 months later. The variables examined point to theoretical and practical problems clinicians might encounter when planning interventions with bereaved families to promote optimal coping, cohesion, and flexibility after a child's violent death.
Effects of Summer and Winter Birth on Growth of Lambs in a Population of Feral Sheep
Authors: Réale Denis , Boussés Patrick
Published: July 2006

The feral sheep of Ile Longue, Kerguelen Archipelago, reproduce twice a year, in summer and winter lambing seasons. We studied effects of birth season on lamb growth (body mass for both sexes and horn length for males) during 3 consecutive years. Lambs of the summer cohort (January–February) grew rapidly during the 3 months following birth, ceased growth during winter (May–September), and resumed growth in spring. Growth was slow during the first 2 months of life for the winter cohort (July–August); winter lambs were lighter than summer lambs at the same age. By the end of winter, when environmental conditions improved, rapid growth of winter lambs allowed them to compensate for their mass deficit. Female lambs tended to be heavier than males early in life, but males achieved greater body mass by the 5th month of age. Significantly larger body mass of males versus females occurred earlier in the winter cohort than the summer cohort. These results suggest that sexual dimorphism may be limited under unfavorable conditions and sexes may allocate energy for growth differently.
Real‐time decision making and aggressive behavior in youth: a heuristic model of response evaluation and decision (RED)
Authors: Fontaine Reid Griffith , Dodge Kenneth A.
Published: July 2006

Considerable scientific and intervention attention has been paid to judgment and decision‐making systems associated with aggressive behavior in youth. However, most empirical studies have investigated social–cognitive correlates of stable child and adolescent aggressiveness, and less is known about real‐time decision making to engage in aggressive behavior. A model of real‐time decision making must incorporate both impulsive actions and rational thought. The present paper advances a process model (response evaluation and decision; RED) of real‐time behavioral judgments and decision making in aggressive youths with mathematic representations that may be used to quantify response strength. These components are a heuristic to describe decision making, though it is doubtful that individuals always mentally complete these steps. RED represents an organization of social–cognitive operations believed to be active during the response decision step of social information processing. The model posits that RED processes can be circumvented through impulsive responding. This article provides a description and integration of thoughtful, rational decision making and nonrational impulsivity in aggressive behavioral interactions. Aggr. Behav. 32:1–21, 2006. © 2006 Wiley‐Liss, Inc.
Biocomposites synthesized from chemically modified soy oil and biofibers
Authors: Tran Phuong , Graiver Daniel , Narayan Ramani
Published: July 2006

Composites with good mechanical properties were prepared from chemically modified soy oils and biofibers without additional petroleum‐based polymers. These composites were prepared from maleic anhydride and epoxide functionalized soybean oils that were cured in the presence of various biofibers (e.g., kenaf, kayocell, protein grits, and solka‐floc) by a flexible amine catalyst. Rigid thermosets characterized by a high‐crosslink‐density network and a high gel fraction were obtained. Fourier transform infrared was used to follow the cure reaction via the disappearance of the characteristic anhydride adsorptions. Composites with high tensile strength and low elongation were obtained when kenaf fibers were treated with (2‐aminoethyl)‐3‐aminopropyl‐trimethoxysilane and then added to the epoxidized/maleated soy matrix and cured with hexamethylenediamine. These biobased composites could provide inexpensive epoxy resin alternatives for a wide variety of industrial applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 69–75, 2006
Synthesis and characterization of novel polythiophenes containing poly(ethylene oxide) side chains
Authors: Qi Li , Sun Ming , Dong Shaojun
Published: July 2006

Thiophene copolymers and their derivatives with poly(ethylene oxide) side chains were synthesized. The starting monomers were 3‐hexylthiophene and 2‐(3‐thienyl) ethanol with poly(ethylene oxide) grafted to the side chains. New functionalized polythiophenes were prepared by both chemical oxidation with FeCl3 and electropolymerization. The conjugating polymers were characterized. The structures of the polythiophene derivatives agreed with the design. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1803–1808, 2006
Amino‐capped aniline trimer/epoxy resin intercrosslinked networks
Authors: Yang Xiaojun , Jiang Yanbin , Zhao Tong , Yu Yunzhao
Published: July 2006

An amino‐capped aniline trimer (ACAT) in emeraldine base form was reacted with an epoxy resin to produce intercrosslinked networks. The quinoid structure of the ACAT was able to crosslink on curing and, thus, led to a very high glass‐transition temperature of the cured resin. The epoxy resin cured with the ACAT showed superior thermal properties over the resins cured with p‐phenylenediamine and 4,4′‐diamino diphenylamine. These findings were based on differential scanning calorimetry, IR, dynamic mechanical analysis, and thermogravimetric analysis data. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 222–226, 2006
Nonequilibrium morphology development in seeded emulsion polymerization. IV. Influence of chain transfer agent
Authors: Stubb Jeffrey M. , Sundberg Donald C.
Published: July 2006

We performed a series of experiments to study the effect of a chain transfer agent, n‐dodecyl mercaptan (n‐DM), on the development of morphology in composite latex particles. The morphologies were determined using a combination of transmission electron microscopy, differential scanning calorimetry, and surfactant titration. The polymer molecular weights were reduced up to 10‐fold with n‐DM levels up to 1.4% in the monomer. The addition of n‐DM can increase the extent to which second‐stage polymer domains are formed within the interior regions of the seed particles, but this is only expected under specific conditions. Numerical simulations support this conclusion. We also observed that the reduction in the molecular weight of the second‐stage polymer did not significantly increase the extent of phase separation and morphology rearrangement within the particles. The overall effect on the morphology was limited. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 945–957, 2006
Active species in hydroperoxide decomposition by hindered amine light stabilizers and its reactivity with phenol
Authors: Yamashita Hiroshi , Banno Katsunori , Ohkatsu Yasukazu
Published: July 2006

Hydroperoxide decomposition by hindered amine light stabilizers (HALSs) is an important process producing active HALS derivatives and has been studied energetically. The decisive active species of the decomposition, however, has not been proposed yet. In this article, HALS nitrosonium that forms in the decomposition of a hydroperoxide by HALSs and a ring‐opening product of the nitrosonium, a nitroso compound, are proposed as active species for hydroperoxide decomposition. Furthermore, the reactivity of the nitrosonium with phenols is discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1310–1317, 2006
Crosslinking of cotton cellulose in the presence of serine and glycine. II. Pore structures and agent distribution
Authors: Chen You‐Jen , Chen Jui‐Chin , Yao Wei‐Hua , Chen Cheng‐Chi
Published: July 2006

Serine and glycine are selected as coreactants to combine with dimethylol‐dihydroxyethyleneurea (DMDHEU). We found that the pore structures of DMDHEU‐crosslinked cottons are changed. DMDHEU alone has lower values of equilibrium absorption, structural diffusion resistance constant, and rate constant, but higher value of activation energy than do DMDHEU–serine and DMDHEU–glycine. On the other hand, DMDHEU–serine has higher values of structural diffusion resistance constant and lower values of equilibrium absorption and rate constant than does DMDHEU–glycine; however, the hydroxyl group contained in serine has the higher affinity toward direct dye resulting in the decrease in the value of activation energy. The expansion patterns of cross section show that the degree of the expansion of the DMDHEU‐crosslinked fiber is lower than that of the DMDHEU–serine‐ and DMDHEU–glycine‐crosslinked fibers. The distribution of crosslinking agents on the crosslinked fabrics reveals the slightly higher surface distribution of DMDHEU–serine and DMDHEU–glycine. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1578–1584, 2006
Modification of a carbon/carbon composite with a thermosetting resin precursor as a matrix by the addition of carbon black
Authors: Ko Tse‐Hao , Kuo Wen‐Shyong , Han Wen‐Teng , Day Tzy‐Chin
Published: July 2006

Carbon/carbon composites were made through the pyrolysis of stabilized PAN felt and phenolic resin with the addition of 5 or 10 wt % carbon black to the matrix and then heat treatment at 600–2500°C. The effects of adding carbon black to the matrix precursor on the physical properties, microstructure, and mechanical properties of the resultant composites were investigated. Adding carbon black not only reduced the weight loss but also limited the shrinkage of the resultant composites. Adding carbon black also accelerated the formation of carbon basal planes in the matrix. At 2500°C, the crystalline stacking height in the composite with 10 wt % added carbon black was 200% greater than that with no additive. The flexural strength of the composite also increased from 15 to 42 MPa (almost 300%). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 333–337, 2006
Dynamic mechanical properties of conductive carbon black‐reinforced closed cell microcellular oil‐extended EPDM rubber vulcanizates: Effect of blowing agent, temperature, frequency, and strain
Authors: Mahapatra S. P. , Tripathy D. K.
Published: July 2006

Dynamic viscoelastic properties of Vulcan XC 72 (excess conductive carbon black)‐reinforced solid‐ and closed‐cell microcellular controlled long chain branching grade oil‐extended EPDM (Keltan 7341A) rubber vulcanizates were studied at four frequencies of 3.5, 11, 35, and 110 Hz, and at a temperature range of −100 to 160°C.The effect of blowing agent (ADC 21) loading on storage modulus (E′) and loss tangent (tan δ) was studied. The log of storage modulus bears a linear relationship with the log of density for both solid and microcellular rubber. Relative storage modulus (E/E) decreases with decrease in relative density (ρf/ρs). Both E′ and tan δ were found to be dependent on frequency and temperature. The master curves of the storage modulus versus log temperature‐reduced frequency were formed by superimposing E′ results and by using shift factors calculated by Arrhenius equation. Strain‐dependent isothermal dynamic viscoelastic properties were carried out for dynamic strain amplitude of 0.08–7%. Cole–Cole plots of microcellular vulcanizates show a circular arc with blowing agent (density). Empirical relationship between tan δ versus E′ is found to be linear, whose slope is independent of blowing agent loading or density. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1600–1608, 2006
Synthesis of nanosized poly(ethyl acrylate) particles via differential emulsion polymerization
Authors: Liu Jianmin , Pan Qinmin
Published: July 2006

Nanoparticles of poly(ethyl acrylate) were synthesized via a semibatch differential emulsion polymerization method with potassium persulfate as the initiator and sodium dodecyl sulfate as the surfactant. The effects of the reaction temperature, aging time, and surfactant/initiator/monomer ratios on the polymer particle sizes were investigated. Poly(ethyl acrylate) with particle sizes of less than 20 nm was synthesized under mild conditions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1609–1614, 2006
Development of high‐definition aqueous polyvinylpyrrolidone photoresists for cathode ray tubes
Authors: Swei Jason , Talbot Jan B.
Published: July 2006

Aqueous photoresists that are capable of higher resolutions than are currently employed by the cathode ray tube (CRT) industry were developed by combining photoactivators, which activate at shorter UV wavelengths with polyvinylpyrrolidone (PVP). Two photoactivators were synthesized: 4,4′‐diazido‐2,2′‐biphenyl disodium disulfonate (DABP), which has a maximum absorbance at 264 nm, and 4,4′‐diazido‐2,2′‐biphenylethane disodium disulfonate (DABPE), which has a maximum absorbance at 258 nm. The PVP/DABP and PVP/DABPE photoresists successfully imaged a pattern with resolution as small as 4.4 μm with photoactivator concentrations greater than 20% of the PVP concentration. Addition of silane and emulgen greatly improved the performance of the photoresists with more uniform coatings of thicknesses of up to 1.4 μm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1637–1644, 2006
Characterization of [poly(ethylene oxide)]LiClO–Li1.3Al0.3Ti1.7(PO4)3 composite polymer electrolytes with poly(ethylene oxide)s of different molecular weights
Authors: Wang Yan‐Jie , Pan Yi , Wang Li , Pang Ming‐Jie , Chen Linshen
Published: July 2006

A group of (PEO)LiClO4–Li1.3Al0.3Ti1.7(PO4)3 [where PEO is poly(ethylene oxide)] composite polymer electrolyte (CPE) films was prepared by the solution‐casting method. In each film, the ethylene oxide/lithium ratio of 8 and the Li1.3Al0.3Ti1.7(PO4)3 concentration of 15 wt % were fixed, but the number‐average molecular weight of PEO was varied (from 5–7 × 104 to 106, 2.2–2.7 × 106, 3–4 × 106, 4–5 × 106, and 5.5–6 × 106). Several techniques, including X‐ray diffraction, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and electrical impedance spectroscopy (EIS), were used to characterize the CPE films. LiClO4 had a strong tendency to complex with PEO, but Li1.3Al0.3Ti1.7(PO4)3 was instead dispersed in the PEO matrix. DSC analysis revealed that the amorphous phase was dominant in the CPE films, although the PEOs before use were quite crystalline. An SEM study showed smooth and homogeneous morphologies for the films with low‐molecular‐weight PEO and dual‐phase characteristics for those with high‐molecular‐weight PEO. The EIS results indicated that the CPE films were all ionic conductors, and the conducting behavior obeyed the Vogel–Tamman–Fulcher (VTF) equation. The parameters in the VTF equation were obtained and discussed with respect to the PEO molecular weights and the crystallinities of the CPE films. Of all the films, the one with PEO with the smallest number‐average molecular weight of 5–7 × 104 had the maximum conductivity, that is, 1.590 × 10−5 S/cm at room temperature and 1.886 × 10−3 S/cm at 373 K. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1328–1334, 2006
Stress relaxation of woodfiber–thermoplastic composites
Authors: Bhattacharyya Debes , Manikath James , Jayaraman Krishnan
Published: July 2006

Woodfiber–polypropylene and woodfiber–waste polyethylene composites have been produced by injection molding and by hot pressing the thermoplastic between woodfiber mats. The stress relaxation under constant strain in these composites has been studied at 25, 50, and 80°C. The results have been compared with similar experiments performed on neat thermoplastics. It is interesting to note that the presence of woodfibers as reinforcement in the composites restricts the stress relaxation, but their effectiveness decrease with the increase in ambient temperature. Composites made by hot pressing the woodfiber mat and the thermoplastic are found to exhibit a lesser amount of relaxation than those made by injection molding the same combination. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 401–407, 2006
Effects of polyvinylpyrrolidone and carbon nanotubes on magnetorheological properties of iron‐based magnetorheological fluids
Authors: Pu Hong Ting , Jiang Feng Jing , Yang Zhenglong , Yan Biao , Liao Xin
Published: July 2006

Magnetorheological (MR) fluids based on glycol, iron powder, polyvinylpyrrolidone (PVP), and carbon nanotubes (CNTs) were prepared. Effects of polyvinylpyrrolidone and carbon nanotubes on sedimentation stability and magnetorheological properties were studied. It is found that the synergetic effects of PVP and CNTs improve the sedimentation stability significantly, and the addition of CNTs reduces the sedimentation velocity and increases the equilibrium sedimentation ratio of the magnetizable particles in MR fluids remarkably. The addition of PVP can reduce the sedimentation velocity of the magnetizable particles, but cannot increase the equilibrium sedimentation ratio and will not change the up trend of apparent viscosity with the increasing intensity of the external magnetic field. When the PVP content is lower, the increment of original apparent viscosity of the MR fluids at zero‐intensity of magnetic field is inconspicuous, and their values of apparent viscosity under magnetic field are similar. However, the apparent viscosity of the MR fluids increases tremendously when the contents of PVP increase to certain degree. The results show that the synergetic effects of PVP and CNTs not only improve the sedimentation stability of the MR fluid but also promote its magnetorheological effect. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1653–1657, 2006
Synthesis and properties of metal complexes of radiation grafted carboxyl containing copolymers
Authors: Turmanova Sevdalina , Vassilev Krassimir , Atanassov Atanas
Published: July 2006

Metal complexes of copolymers based on polyacrylic acid radiation grafted onto films of low density polyethene were prepared by complex‐forming with solutions of salts of FeCl3.6H2O, CuCl2.2H2O, CoCl2.6H2O, NiCl2.6H2O, VOSO4.5H2O, Na2MoO4.2H2O, Na2WO4.2H2O, and NH4VO3. The introduction of metal ions was found to depend mainly on the degree of grafting of acrylic acid and was from 0.5 to 5.0 mass%. These complexes were characterized by IR, UV spectroscopy, and EPR. The moisture content of the materials obtained changed linearly with the degree of grafting of acrylic acid and was from 9.0 to 80.0%. The introduction of the MoO22+ and WO22+ towards carboxylic groups lead to increasing the thermal stability of the metal complexes of the copolymers compared to the initial grafted films. The modified acrylate copolymers were studied in reactions of catalytic oxidation of cyclohexene. The activities of the complexes obtained towards cyclohexene epoxidation can be arranged in the following order: PAA–MoO22+ > PAA–VO2+ > PAA–VO > PAA–WO22+, while for the reaction of cyclohexene hydroxylation the order was—PAA–Co2+ > PAA–Cu2+ > PAA–Fe3+ > PAA–Ni2+. The contents of cyclohexene oxide and 2‐cyclohexene‐1‐ol reached 38.5% and 7.5%, respectively.
© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1658–1665, 2006
Anthranilic acid assisted preparation of Fe3O4–poly(aniline‐co‐o‐anthranilic acid) nanoparticles
Authors: Chao Danming , Lu Xiaofeng , Chen Jingyu , Zhang Wanjin , Wei Yen
Published: July 2006

Magnetic Fe3O4–poly(aniline‐co‐o‐anthranilic acid) nanoparticles were prepared by a novel and simple method: anthranilic acid assisted polymerization. The synthetic strategy involved two steps. First, Fe3O4 nanoparticles capped by anthranilic acid were obtained by a chemical precipitation method, and then the aniline and oxidant were added to the modified Fe3O4 nanoparticles to prepare well‐dispersed Fe3O4–poly(aniline‐co‐o‐anthranilic acid) nanoparticles. Fe3O4–poly(aniline‐co‐o‐anthranilic acid) nanoparticles exhibited a superparamagnetic behavior (i.e., no hysteresis loop) and high‐saturated magnetization (Ms = 21.5 emu/g). The structure of the composite was characterized by Fourier‐transform infrared spectra, X‐ray powder diffraction patterns, and transmission electron microscopy, which proved that the Fe3O4–poly(aniline‐co‐o‐anthranilic acid) nanoparticles were about 20 nm. Moreover, the thermal properties of the composite were evaluated by thermogravimetric analysis, and it showed excellent thermal stability.
© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1666–1671, 2006
Electrospinning of polyacrylonitrile nanofibers
Authors: Wang Tong , Kumar Satish
Published: July 2006

Polyacrylonitrile (PAN) was electrospun in dimethylformamide as a function of electric field, solution flow rate, and polymer concentration (C). The fiber diameter increased with C and ranged from 30 nm to 3.0 μm. The fiber diameter increased with the flow rate and decreased when the electric field was increased by a change in the working distance; however, it did not change significantly when the electric field was varied by a change in the voltage at a given working distance. The fibers below about 350 nm diameter contained beads, whereas above this diameter, bead‐free fibers were obtained. For PAN with a molecular weight of 100,000 g/mol, the fiber diameter scaled as C1.2 and C7.5 at low (5.1–16.1 wt %) and high (17.5–22.1 wt %) C values, respectively. Both concentrations were in the semidilute entangled regime, where the specific viscosity scaled as C4.4, consistent with De Gennes's scaling concepts. In the semidilute unentangled regime (0.5–3.1 wt %), where the viscosity scaled as C1.3, microscopic or nanoscopic particles rather than fibers were obtained. Concentration‐ dependent electrospinning studies were also carried out for higher molecular weight PAN (250,000 and 700,00 g/mol). The results of these studies are also presented and discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1023–1029, 2006
Adsorption of fibrinogen onto macroporous, biocompatible sponges based on poly(2‐hydroxyethyl methacrylate)
Authors: Bajpai A. K. , Mishra D. D.
Published: July 2006

Hydrophilic, spongy matrices of poly (2‐hydroxyethyl methacrylate) were synthesized by a redox polymerization method, and the adsorption of fibrinogen was carried out on their surfaces. The prepared sponges were characterized with Fourier transform infrared and environmental scanning electron microscopy and were assayed for their water‐sorption potential. The chemical architecture of the sponges had a pronounced impact on both the water sorption and the protein adsorption affinity of the sponge surface. The adsorption kinetics were investigated, and kinetic parameters such as the rate constants for adsorption and desorption and the penetrate rate constant were evaluated. The influence of experimental conditions such as the pH and temperature were observed on the adsorption profiles of fibrinogen. The prepared sponges were also judged for in vitro blood compatibility by methods such as blood‐clot‐formation and hemolysis‐percentage tests. An attempt was also made to correlate the fibrinogen adsorption capacity of the sponge to its antithrombogenic response to static blood. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1341–1355, 2006
Evaluation of the effects of biobased plasticizers on the thermal and mechanical properties of poly(vinyl chloride)
Authors: Gil N. , Saska M. , Negulescu I.
Published: July 2006

Blends were prepared of poly(vinyl chloride) (PVC) with four different plasticizers; esters of aconitic, citric, and phthalic acids; and other ingredients used in commercial flexible PVC products. The thermal and mechanical properties of the fresh products and of the products after 6 months of aging were measured. Young's modulus of the PVC blends was reduced about 10‐fold by an increase in the plasticizer level from 15 to 30 phr from the semirigid to the flexible range according to the ASTM classification, but a 40‐phr level was required for PVC to retain its flexibility beyond 6 months. At the 40‐phr level, tributyl aconitate performed better than diisononyl phthalate (DINP) or tributyl citrate, in terms of lowering Young's modulus, both in the fresh materials and those aged for 6 months. The effects of the four plasticizers on the glass‐transition temperature (Tg) were similar, with Tg close to ambient temperature at the 30‐ and 40‐phr levels in freshly prepared samples and at 40–60°C in those aged for 6 months. The thermal stability of the PVC plasticized with DINP was superior among the group. Overall, tributyl aconitate appeared to be a good candidate for use in consumer products where the alleged toxicity of DINP may be an issue. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1366–1373, 2006
Kinetics of the curing reaction of unsaturated polyester resins catalyzed with new initiators and a promoter
Authors: Worzakowska Marta
Published: July 2006

In this article, the curing of unsaturated polyester resins catalyzed with a promoter [cobalt(II) octoate] and free‐radical initiators is presented. The new initiators were formed by the oxidation process of ethyl methyl ketone or cyclohexanone with hydrogen peroxide and the mixture of solvents containing hydroxyl groups. As a reference, a typical curing system containing ethyl methyl ketone hydroperoxide (Luperox) and the promoter was used. The differential scanning calorimetry runs were performed at different heating rates. The experimental data were fitted with the empirical kinetic model. First, the kinetic parameters (activation energy, frequency factor, and reaction order) were obtained with a single reactive process and with the nth‐order reaction f(α), the nth‐order reaction f(α) with autocatalysis, and the first‐order reaction f(α) with autocatalysis. Second, two or three different reactive processes with the nth‐order reaction f(α) for each step were used. The obtained values of the activation energies for the curing of the unsaturated polyester resins with the free radical initiator–cobalt(II) salt catalytic system were in the range 40–60 kJ/mol for the polymerization initiated by the redox decomposition of the initiators and 80–90 kJ/mol for the polymerization initiated by the thermal decomposition of the initiators at high temperatures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1870–1876, 2006
Experimental analysis of temperature and crystallinity profiles of wood sawdust/polypropylene composites during cooling
Authors: Sombatsompop N. , Kositchaiyong A. , Wimolmala E.
Published: July 2006

The temperature profiles of wood sawdust/polypropylene (PP) composite melts during cooling were experimentally investigated with a cooling jacket apparatus connected to the end of an injection‐molding machine. Real‐time melting temperature was measured with an unsheathed thermocouple array coupled with a high‐speed data‐acquisition unit. The crystallinity level of the solidified composites was evaluated with an X‐ray diffractometer. Before the crystallization temperature (Tc) was reached, the cooling rate of the melt layer near the wall was greater than that near the center. After Tc was reached, the opposite behavior was observed. Wood sawdust content did not affect the general temperature and crystallinity profiles across the duct diameter but led to more nonuniform temperature profiles across the duct diameter. The sawdust particles could act as a nucleating agent during the nucleation stage to increase Tc of the PP and as an interfering agent during the crystal growth stage to decrease the overall crystallinity level of the PP. The temperature and crystallinity profiles were not affected by the coolant flow rate. The normalized induction time changed with reduced radius (r/R, where r is the distance between the central duct to any point along the cross‐section of the duct and R is the duct radius) positions and coolant flow rate, especially for neat PP and PP composites with a low sawdust content (10 wt %). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1896–1905, 2006
Homogeneous graft copolymerization of chitosan with butyl acrylate by γ‐irradiation via a 6‐O‐maleoyl‐N‐phthaloyl‐chitosan intermediate
Authors: Huang Meifang , Xia Xu , Zhang Zhongcheng , Liu Li , Fang Yue'e
Published: July 2006

The graft copolymerization of butyl acrylate (BA) onto chitosan was tried via a new protection‐graft‐deprotection procedure. About 6‐O‐maleoyl‐N‐phthaloyl‐chitosan was synthesized and characterized by Fourier transform infrared spectra analysis (FT‐IR) and 1H‐NMR. Because the intermediate 6‐O‐maleoyl‐N‐phthaloyl‐chitosan was soluble in organic solvents, the graft copolymerization was carried out in a homogeneous system. Grafting was initiated by γ‐irradiation. The graft extent was dependent on the irradiation dose and the concentration of BA monomer, and copolymers with grafting above 100% were readily prepared. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 489–493, 2006
Photoregulated complexation, redox behavior, and photoluminescence of a supramolecular polymer solution
Authors: Dahmane Smail , Zhao Yue
Published: July 2006

Reported in this paper is a new finding based on a spectroscopic and electrochemical study of a supramolecular polymer in dilute solution. Dissolved in a mixture of dichloromethane and acetonitrile, zinc‐tetraphenylporphyrin (ZnTPP) can complex with a polymethacrylate bearing an azopyridine moiety (AzPy) through the axial coordination between the metal and pyridyl group. The self‐assembled polymer (PAzPy–ZnTPP) displays different photoluminescence and redox behaviors compared with those of noncomplexed ZnTPP. Moreover, the reversible trans–cis‐photoisomerization of azopyridine upon UV and visible light irradiation was found to alter the equilibrium of the axial coordination between azopyridine and ZnTPP in solution, resulting in photoregulable redox potentials and fluorescence emission of the metalloporphyrin. The results suggest that supramolecular polymer solutions could enhance the mechanism of photoinduced change in the degree of complexation, which gives rise to a phenomenon of photoregulation of the electrochemical and optical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 744–750, 2006
Capillary effect of hydrophobic polyester fiber bundles with noncircular cross section
Authors: Zhang Y. , Wang H. P. , Chen Y. H.
Published: July 2006

Moisture transport in fiber assembly is one of the critical factors affecting physiological comfort. It is useful to model bundle structure for understanding capillary flow in complex geometries representative of the void spaces formed between fibers. A new mathematical model MFB has been used to simulate alignment representative of void spaces formed between fibers in noncircular cross section fiber bundles. Fiber morphological character and their random packing pattern are emphasized to discuss the mechanism of capillary flow in fiber assembly in this work. Capillary equivalent radius distribution, flux of saturated fiber bundle, capillary generating ability, and wicking velocity are computed to predict which kind of shape is predominant for hydrophobic polyester fiber wicking. Vertical wicking model of polyester filaments bundle predicts that as the nonroundness of filaments increase, the maximum liquid height, flux of saturated bundle, and capillary forming ability will increase, while instantaneous wicking velocity increases not stably. Concave polygon shape of fiber bundle has much more small capillary tubes than convex shape of fiber bundle. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1405–1412 2006
The preparation of core‐shell CaCO3 particles and its effect on mechanical property of PVC composites
Authors: Xiong Ying , Chen Guangshun , Guo Shaoyun
Published: July 2006

In this study, a novel mechanochemical route to prepare core‐shell structured particles was introduced. XPS, TEM, and dissolving experimental results indicate the formation of [(inorganic particle)/(elastomer)] core‐shell structured particles, and several kinds of calcium carbonate (nano‐CaCO3) particles with various interfaces were obtained. The mechanical properties and morphological results indicate that the surface treatment of nano‐CaCO3 particles and the existence of outer elastic layer will strengthen the interfacial interaction between nano‐CaCO3 particles and PVC matrix, which results in improvement of mechanical properties of PVC/CaCO3 composites. The theoretical calculations of the interfacial interaction and DMA results confirm these especially when the surface of nano‐CaCO3 particles was treated by MMA and coated in succession by ACR through vibro‐milling. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1084–1091, 2006