bluuebunny/crossref_metadata_2025 huggingface dataset:
Relative Efficacy of a Multisession Sexual Risk–Reduction Intervention for Young Men Released From Prisons in 4 States
Authors: Wolitski Richard J. ,   and the Project START Writing Group
Published: September 2006

Objectives. We compared the effects of an enhanced multisession intervention with a single-session intervention on the sexual risk behavior of young men released from prison.

Methods. Young men, aged 18 to 29 years, were recruited from US prisons in 4 states and systematically assigned to the prerelease single-session intervention or the pre- and postrelease enhanced intervention. Both interventions addressed HIV, hepatitis, and other sexually transmitted infections; the enhanced intervention also addressed community reentry needs (e.g., housing, employment). Assessment data were collected before intervention, and 1, 12, and 24 weeks after release.

Results. A total of 522 men were included in intent-to-treat analyses. Follow-up rates ranged from 76% to 87%. Unprotected vaginal or anal sex during the 90 days before incarceration was reported by 86% of men in the enhanced intervention and 89% in the single-session intervention (OR=0.78; 95% CI=0.46, 1.32). At 24 weeks, 68% of men assigned to the enhanced intervention reported unprotected vaginal or anal sex compared with 78% of those assigned to the single-session intervention (OR=0.40; 95% CI=0.18, 0.88).

Conclusion. Project START demonstrated the efficacy of a sexual risk–reduction intervention that bridges incarceration and community reentry.
Mild Cognitive Impairment in Early Life and Mental Health Problems in Adulthood
Authors: Chen Chuan-Yu , Lawlor John P. , Duggan Anne K. , Hardy Janet B. , Eaton William W.
Published: September 2006

Objectives. We assessed the extent to which borderline mental retardation and mental retardation at preschool ages are related to emotional and behavioral problems in young adulthood. We also explored early risk factors for having mental health problems as a young adult that might be related to preschool differences in cognitive ability.

Methods. We used data from a cohort of births studied in the Johns Hopkins Collaborative Perinatal Study and followed up in the Pathways to Adulthood Study. Preschool cognitive functioning was assessed at 4 years of age. Individual characteristics, psychosocial factors, and mental problems were prospectively evaluated from birth through young adulthood.

Results. Children with subaverage cognitive abilities were more likely to develop mental health problems than their counterparts with IQs above 80. Inadequate family interactions were shown to increase 2- to 4-fold the risk of emotional or behavioral problems among children with borderline mental retardation.

Conclusions. Subaverage cognitive functioning in early life increases later risk of mental health problems. Future research may help to delineate possible impediments faced at different developmental stages and guide changes in supportive services to better address the needs of children with borderline mental retardation.
Public Conceptions of Serious Mental Illness and Substance Abuse, Their Causes and Treatments: Findings from the 1996 General Social Survey
Authors: Kuppin Sara , Carpiano Richard M.
Published: September 2006

Objectives. We examined the degree to which lay beliefs about the causes of disorders may predict beliefs about what constitutes appropriate treatment.

Methods. We analyzed randomized vignette data from the MacArthur Mental Health Module of the 1996 General Social Survey (n=1010).

Results. Beliefs in biological causes (i.e., chemical imbalance, genes) were significantly associated with the endorsement of professional, biologically focused treatments (e.g., prescription medication, psychiatrists, and mental hospital admissions). Belief that the way a person was raised was the cause of a condition was the only nonbiologically based causal belief associated with any treatment recommendations (talking to a clergy member).

Conclusions. Lay beliefs about the biological versus nonbiological causes of mental and substance abuse disorders are related to beliefs regarding appropriate treatment. We suggest areas for further research with regard to better understanding this relationship in an effort to construct effective messages promoting treatment for mental health and substance abuse disorders.
Sudden Infant Death Syndrome and Reported Maternal Smoking During Pregnancy
Authors: Shah Tushar , Sullivan Kevin , Carter John
Published: September 2006

We investigated the effect of maternal smoking during pregnancy on the relative risk of sudden infant death syndrome (SIDS) by linking data from Georgia birth and death certificates from 1997 to 2000. We estimated the effect of misclassifying smokers as non-smokers and the effect of being misclassified on SIDS rates, and we calculated the fraction of cases caused by exposure. Of all SIDS cases, 21% were attributable to maternal smoking; among smokers, 61% of SIDS cases were attributable to maternal smoking. Maternal smoking during pregnancy is associated with a significantly increased risk of SIDS.
Characteristics of Black and White Suicide Decedents in Fulton County, Georgia, 1988–2002
Authors: Abe Karon , Mertz Kristen J. , Powell Kenneth E. , Hanzlick Randy L.
Published: September 2006

Objectives. We compared the prevalence of risk factors for Black and White suicide decedents in Fulton County, Georgia, from 1988–2002.

Methods. We used data from the Fulton County Medical Examiner’s Office to compile information on suicides that occurred in Fulton County between 1988 and 2002. We used the χ2test and logistic regression to identify associations between suicide risk factors and race.

Results. Black suicide decedents were more likely than White suicide decedents to be male (odds ratio [OR]=2.06; 95% confidence interval [CI]=1.38, 3.09), to be younger, (≤24 y [OR = 4.74; 95% CI = 2.88, 7.81]; 25–34 y [OR = 2.79; 95% CI = 1.74, 4.47]; 35–44 y [OR = 1.86; 95% CI = 1.13, 3.07]), and to hurt others in a suicide (OR = 4.22; 95% CI = 1.60, 11.15) but less likely to report depression (OR=0.63; 95% CI=0.48, 0.83), to have a family history of suicide (OR=0.08; 95% CI=0.01, 0.61), or to leave a suicide note (OR=0.37; 95% CI=0.26, 0.52).

Conclusions. Future research should consider that Black suicide decedents are less likely to report depression than White suicide decedents. This suicide risk difference is important when developing effective suicide prevention programs.
Letrozole: A Well-Tolerated and Effective Treatment for Breast Cancer
Authors: Bundred Nigel J
Published: September 2006

Letrozole, an aromatase inhibitor, demonstrates consistent superiority over tamoxifen in various treatment settings, has the only significant survival advantage according to results from a Phase III randomized trial, and is the only aromatase inhibitor approved as an extended adjuvant therapy in the treatment of breast cancer. Initial adjuvant letrozole significantly prolongs disease-free survival, especially reducing the risk of distant metastasis, and offers a significant disease-free survival benefit to patients at an increased risk of relapse (node-positive and chemotherapy-treated patients) when compared with tamoxifen. These findings led to its recommendation as an initial adjuvant therapy in the latest St Gallen guidelines. Similar findings were reported when letrozole was administered after completion of 5 years of adjuvant tamoxifen. The benefit of letrozole also increases with the duration of treatment. Overcoming the development of resistance to endocrine therapy is under investigation. As a potent aromatase inhibitor, letrozole is the ideal drug for tailored combination treatment regimens of the future.
Rethinking Gender-Specific Medicine
Authors: Legato Marianne J
Published: September 2006

The past 15 years have produced enormous advances in our understanding of the unique features of biological sex. Nevertheless, important and different tasks remain. One of these is to address the difficulties inherent in including premenopausal women in prospective, randomized trials characterizing the impact of new drugs and interventions. A second compelling mandate is to expand our knowledge of men using the same concentration on the unique features of male biology as we have used in studying women. The inclusion of men in our scientific investigations is a natural evolution of our development of the discipline of gender-specific medicine and will yield the same rich harvest as has our work in women's health.
Extended and Continuous Use of Hormonal Contraceptives to Reduce Menstruation
Authors: Wiegratz Inka , Kissler Stefan , Kuhl Herbert , Kaufmann Manfred
Published: September 2006

During the use of long-cycle regimens of monophasic oral contraceptives, the total number of bleeding and cycle-dependent complaints is considerably lower than during conventional treatment with oral contraceptives. Despite an initially higher rate of irregular bleeding, the majority of women prefer the long-cycle treatment since it may improve quality of life. As this regimen provides an enhanced ovarian suppression, it may prevent pregnancies, especially in noncompliant women or patients who are concomitantly treated with drugs that may impair the efficacy of oral contraceptives. Postponement or suppression of withdrawal bleeding also reduces menses-associated disorders such as menorrhagia and dysmenorrhea, and has beneficial effects in patients with hemorrhagic diathesis, endometriosis, uterine leiomyomas and polycystic ovary syndrome. Long-term studies are necessary to assess the impact of long-term use of extended regimens of oral contraceptives on safety, for example, the risk of cancer and cardiovascular disease, and on fertility after discontinuation of treatment.
Membrane Technology
Authors: Baker Richard W. ,   Updated by Staff
Published: September 2006

Membranes have gained an important place in chemical technology and are being used increasingly in a broad range of applications. The key property that is exploited in every application is the ability of a membrane to control the permeation of a chemical species in contact with it. This article provides a general overview of the entire membrane area. After a review of the historical development of membranes, the principal types of membrane are described briefly. The manufacture of the more important types of membrane and the packaging of membranes in modules to exploit their properties are discussed. The principal membrane applications, including microfiltration, ultrafiltration, reverse osmosis, pervaporation, gas separation, and controlled drug delivery are described. The particular focus is on the use of membranes to solve separation problems. A detailed section on membrane reactors is included. More complete descriptions of some of the important specific applications of membranes are given elsewhere.
Sodium and Sodium Alloys
Authors: Lemke Charles H. , Markant Vernon H.
Published: September 2006

Of all the alkali metals, sodium has had perhaps the greatest commercial success, owing to its relative ease of manufacture and its important role worldwide in the manufacture of organolead compounds for use as gasoline octane enhancers. The decline of organoleads in North America has greatly affected U.S. production. Other sodium uses exist, but none requiring the massive quantities needed for lead antiknock compounds. Most sodium is made electrolytically. Various electrochemical cells are described. Sodium continues to have an important role in the manufacture of many organic chemicals as a reducing agent. Newer uses include sodium batteries, flue‐gas cleanup, and alloy surface modification.
Terpenoids
Authors: Sell Charles S.
Published: September 2006

The terpenoids are a family of natural products defined as being those possessing a carbon skeleton based on isoprene units. This skeletal feature stems from their biosynthesis from mevalonic acid. They serve a wide range of functions in nature including defensive resins, pheromones, antioxidants, and the pigments responsible for vision. It is not surprising therefore that they are also of considerable importance commercially and find application as flavors, fragrances, agrochemicals, and pharmaceuticals. Volatile terpenoids, such as geraniol, linalool, citronellol, citral, and the ionones and damascones, are important in the flavor and fragrance industry. Campholenic aldehyde, the precursor for a range of sandalwood odored materials, is an example of a key terpenoid intermediate. Currently, the best‐known terpenoid pharmaceutical is probably the anticancer drug paclitaxel.

Industrial routes to terpenoid compounds comprise an interesting mixture of extraction from nature, partial synthesis from natural feedstocks and total synthesis from petrochemicals. In many instances, two or even all three of these possibilities exist in technocommercial equilibrium. Principal feedstocks include α‐pinene, β‐pinene, myrcene, limonene, isoprene, isobutylene, acetone, and acetylene.

In this article, a brief summary of the biosynthesis of terpenoids is followed by a description of the main industrial routes to those of commercial importance. The remainder comprises a series of monographs on the commercially more important members of the family including monoterpenes, oxygenated monoterpenoids, sesquiterpenoids, diterpenoids, triterpenoids, carotenoids, and terpenoid degradation products, such as the ionones, damascones, and ambergris chemicals.
Follow‐up of the course of the anionic ring‐opening polymerization of lactams onto an isocyanate‐bearing polymer backbone in the melt
Authors: Hu Guo‐Hua , Li Huxi , Feng Lian‐Fang
Published: September 2006

In this study, a batch mixer was used as a rheoreactor to carry out and follow up in real time the rate of the anionic polymerization of ε‐caprolactam onto a 3‐isopropenyl‐α,α‐dimethylbenzene isocyanate bearing polypropylene (PP‐g‐TMI) in the presence of sodium ε‐caprolactam as a catalyst. The isocyanate group in the PP‐g‐TMI was capable of activating the anionic polymerization, leading to the formation of a graft copolymer with polypropylene as the backbone and polyamide 6 as the grafts. The polymerization rate was related to the viscosity increase of the polymerization system. The latter then resulted in a concomitant torque increase. It was shown that torque was a rapid, convenient, and approximate measure of the polymerization rate. The use of the torque allowed for rapid and approximate evaluation of the effects of chemical and operating conditions on the polymerization rate without the need to determine the monomer conversions. Torque profiles were also a very useful piece of information for the design of a reactive extrusion process for the same type of polymerization system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4394–4403, 2006
Evolution of tension during the thermal stabilization of polyacrylonitrile fibers under different parameters
Authors: Yu Meijie , Wang Chengguo , Bai Yujun , Wang Yanxiang , Zhu Bo
Published: September 2006

Complicated physical and chemical reactions can occur during the thermal stabilization of polyacrylonitrile (PAN) fibers, and they can be macroscopically reflected by the evolution of tension in the fibers. In this work, PAN fibers were oxidized under different parameters in a continuous production line. The tension in the fibers was examined in detail and found to be influenced greatly by the stretching ratio, temperature, and time, as well as the porosity of the PAN precursors. As the thermal stabilization proceeded, tension with different characteristics could result from various reaction mechanisms. At the initial stage, a higher temperature was helpful for lowering the tension, but the tension increased with an increasing stretching ratio. In a later stage, the tension was dominantly dependent on the cyclization reaction and increased with increasing temperature or time. Under the same stabilization conditions, the tension in low‐porosity fibers was higher than that in high‐porosity fibers. The microstructures, characterized by high‐resolution transmission electron microscopy, provided some direct evidence for the partially stabilized fibers that the stabilization in the crystalline phase was slower than that in the amorphous phase. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5500–5506, 2006
Pyrrole chemical polymerization on textiles: Kinetics and operating conditions
Authors: Ferrero Franco , Napoli Liuba , Tonin Claudio , Varesano Alessio
Published: September 2006

The chemical polymerization of pyrrole was studied with the aim of defining the best operating conditions for obtaining conductive fabrics of synthetic fibers. Ammonium persulfate was chosen as the oxidant, and various dopants were tested. Among these, naphtalene‐2,6‐disulfonic acid disodium salt enabled the lowest surface resistivity to be reached. Hence, several kinetic runs were performed to explain the influence of some operating conditions as oxidant concentration and temperature. A pseudo‐first‐order kinetic equation was derived, and the reaction rates were found to be practically unaffected by the presence of the textile substrate. Pyrrole polymerization was faster than adsorption of the monomer, suggesting the hypothesis of fast polymerization outside the fibers followed by adsorption onto the fiber surface. The surface coating of polypyrrole was evidenced by microscopic observation of the fiber cross sections. ©2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4121–4126, 2006
Preparation of titanium dioxide/polyacrylate nanocomposites by sol–gel process in reverse micelles and in situ photopolymerization
Authors: Wan Tao , Wang Yue‐Chuan , Feng Fei
Published: September 2006

UV‐curable, transparent acrylic resin/titania organic–inorganic hybrid films were prepared by controlled hydrolysis of titanium tetrabutoxide in Span‐85/Tween 80 reverse micelles and the subsequent in situ photopolymerization of the acrylic monomers. UV–vis spectra and atomic force microscopy (AFM) indicated the presence of a nanoscale hybrid composition. The onset of absorption (λonset) of titania in the hybrids appeared between 363.4 and 383.5 nm, which exhibited blue shifts relative to that of bulk anatase (λonset = 385 nm). The titania content increased rapidly at higher temperature and higher TTB content, whereas it increased slowly with longer post‐thermal treatment times. The refractive index and UV shielding properties of the organic polymer were obviously improved with increasing titania content. AFM images showed the inorganic domains (mean size 25.3–28.8 nm) were uniformly dispersed in the polymeric networks. The roughness parameters of the hybrid material were: toughness, 1.5–2.3 nm; root mean square roughness, 4.5–4.6 nm; and peak and valley distance, 9.7–19.4 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5105–5112, 2006
Percolation threshold of electrically conductive master batch for polyester fibers application
Authors: Jin Xin , Xiao Changfa , An Shulin , Jia Guangxia
Published: September 2006

In the case of the electrically conductive master batch (ECMB) for fibers application, higher filler content required to produce adequate conductivity can be accompanied by a reduction in spinnability and mechanical property of final fibers. To minimize these problems, ECMB with the character of lower percolation threshold was designed in this article. Carbon black (CB) was treated by titanate coupling agent. Polymer blend poly(ethylene terephthalate) (PET)/polyethylene(PE) was used as matrix instead of individual polymer matrix. The effects of titanate coupling agent treatment and the composition of polymer blend on the properties of ECMB have been discussed. FTIR and laser particle size distribution analyzer were employed to study the CB. Solubility tests and positive temperature effect peak were used to verify the distribution of CB in the polymer blend. These results showed that CB treated with 2 wt % titanate coupling agent and PET/PE polymer blend with the weight ratio of 60/40 appear to be an effective way to design the ECMB with a low percolation threshold. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4144–4148, 2006
Thermal degradation kinetics of rigid polyurethane foams blown with water
Authors: Li Xiao‐Bin , Cao Hong‐Bin , Zhang Yi
Published: September 2006

The thermal decomposition behavior of rigid polyurethane foams blown with water was studied by dynamic thermogravimetric analysis (TGA) in both nitrogen and air atmosphere at several heating rates ranging from room temperature to 800°C. The kinetic parameters, such as activation energy (E), degradation order (n), and pre‐exponential factor (A) were calculated by three single heating rate techniques of Friedman, Chang, and Coats–Redfern, respectively. Compared with the decomposition process in nitrogen, the decomposition of foams in air exhibits two distinct weight loss stages. The decomposition in nitrogen has the same mechanism as the first stage weight loss in air, but the second decomposition stage in air appears to be dominated by the thermo‐oxidative degradation. The heating rates have insignificant effect on the kinetic parameters except that the kinetic parameters at 5°C/min have higher values in nitrogen and lower values in air, indicating different degradation kinetics in nitrogen and air. The kinetic parameters of foam samples blown with different water level in formulation decline firstly and then increase when water level increases from 3.0 to 7.0 pph. According to the prediction for lifetime and half‐life time of foams, water‐blown rigid foams have excellent thermostability, when used as insulation materials below 100°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4149–4156, 2006
Flame retardant synergism of GUP and boric acid by cone calorimetry
Authors: Gao Ming , Yang Shousheng , Yang Rongjie
Published: September 2006

Wood was treated with a new composite flame retardant (FRW), with its components guanyl urea phosphate (GUP) and boric acid (BA) to impart flame retardance. The flame retarding behavior of these samples was valued by cone calorimeter. The flammability parameters, including rate of heat release (RHR), total heat release (THR), effective heat of combustion (EHC), total mass loss (TML) and mass loss rate (MLR), yield of CO, smoke production rate (SPR), and specific extinction area (SEA) were recorded simultaneously. By analyzing these data, it was concluded that most combustion parameters of wood decreased by the treatment, especially for the FRW treatment, considerably decreased while the date for wood treated with GUP or boric acid decreased much less for the similar upload, which indicated a synergistic effect of flame retardance and suppressing smoke between GUP and boric acid in FRW, which has not been reported in other researches until now. Meanwhile, the probable flame retardation mechanism was proposed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5522–5527, 2006
Chemiluminescence of isotactic polypropylene induced by photo‐oxidative degradation and natural weathering
Authors: Jipa Silviu , Setnescu Radu , Zaharescu Traian , Setnescu Tanta , Kaci Mustapha , Touati Naima
Published: September 2006

The analysis of the chemiluminescence (CL) kinetic parameters (induction time, oxidation rate, and activation energy) after the UV irradiation and outdoor exposure of isotactic polypropylene (i‐PP) films have been studied. The initial CL emission intensity increased with increasing photodegradation time of i‐PP films. On photodegradation, the activation energies were found to decrease linearly with time of UV‐irradiation and outdoor exposure. The slopes of these linear dependences were used to indicate the degree of photodegradation of the polymer and also for the characterization of the stabilizing effect of the additive. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4623–4629, 2006
Removal of copper ions from water of boilers by a modified natural based, corncobs
Authors: Billon L. , Meric V. , Castetbon A. , Francois J. , Desbrieres J.
Published: September 2006

The objective of this study is to demonstrate the feasibility of using esterified derivatives of corncobs to clean back condensates from high‐pressure industrial boilers. Copper ions were retained by these modified natural polymers based within working pH and temperature conditions even at very low concentrations as 10−12 mol/L. Acrylamide polymers or derivatives were not successful for such applications. The influence of granulometry of crude corncobs and temperature on copper retention was first studied using UV spectroscopic and voltametry techniques. Then esterified derivatives were considered and succinic anhydride derivatives of corncobs are demonstrated to be more efficient than the maleic anhydride derivatives. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4637–4645, 2006
Recycling of NR based cured latex material reclaimed with 2,2′‐dibenzamidodiphenyldisulphide in a truck tire tread compound
Authors: Rajan V. V. , Dierkes W. K. , Joseph R. , Noordermeer J. W. M.
Published: September 2006

It is observed that reclamation of natural rubber latex based rubber using 2,2′‐dibenzamidodiphenyldisulphide as reclaiming agent is an optional methodology for recycling of waste latex rubber (WLR). For progressive replacement of virgin natural rubber by the reclaim, two alternatives curing system were investigated: adjustment or reduction of the curing system with increasing reclaim content, to compensate for the extra amount of curatives brought along by the reclaim. For fixed curing system, as if the reclaim were equivalent to virgin NR. The cure behavior, final crosslink density and distribution, mechanical properties, and dynamic viscoelastic properties of the blends with reclaimed WLR are measured and compared with the virgin compound. The morphology of the blends, sulfur migration, and final distribution are analyzed. The mechanical and dynamic viscoelastic properties deteriorate for both curing systems, but to a lesser extent for fixed curing system compared to adjusted curing system. With the fixed cure system, many properties like tensile strength and compression set do still deteriorate, but tan δ and M300/M100, representative for the rolling resistance of tires are improved. On the other hand, with the adjusted cure system both mechanical and dynamic properties still deteriorate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4194–4206, 2006
Synthesis and characterization of butan‐1‐ol modified toluene diisocyanate trimer
Authors: Jin C. , Lu J. , Li W. S. , Zhou L. , Huang Q. M. , Yang X. H.
Published: September 2006

Butan‐1‐ol modified toluene diisocyanate tri mer (TDI‐trimer) was synthesized and characterized with Fourier transform infrared spectroscopy, gel permeation chromatography, and thermal gravimetry analysis techniques. The modified TDI‐trimer showed good dissolvable ability with hydroxy resin and can be used to produce paints with acrylic polyol resin. The thermal stability of the modified TDI‐trimer was improved by simply increasing both the amount of catalyst and the ratio of NCO/OH, less depended on the kind of catalyst. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4958–4962, 2006
Spectroscopic and electrical properties of polyaniline/CeO2 composites and their application as humidity sensor
Authors: Parvatikar Narsimha , Jain Shilpa , Bhoraskar S. V. , Ambika Prasad M. V. N.
Published: September 2006

Polyaniline/CeO2 composites were synthesized by in situ chemical polymerization method using ammonium persulphate as an oxidizing agent. This is the single step polymerization process for the direct synthesis of emeraldine salt phase of polymer. The polymers were characterized by using FTIR spectral analysis, SEM, and XRD studies. Formation of conducting emeraldine salt phase is confirmed by spectroscopic techniques. High temperature conductivity measurements show “thermal activated behavior.” The change in resistance with respect to percentage relative humidity (% RH) is observed, when the pressed pellets of the polymer were exposed to the broad range of humidity (humidity ranging between 10 and 95% RH). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5533–5537, 2006
Synthesis of poly(acrylic acid)/sodium humate superabsorbent composite for agricultural use
Authors: Mo Chu , Shu‐quan Zhu , Hua‐Min Li , Zhan‐bin Huang , Shu‐qin Li
Published: September 2006

A novel poly (acrylic acid)/sodium humate superabsorbent composite was synthesized by graft copolymerization reaction of acrylic acid (AA) on sodium humate micropowder using N,N′‐methylenebisacrylamide (MBA) as a crosslinker and potassium peroxydisulfate (KPS) as an initiator in aqueous solution. The effects on water absorbency of factors such as reaction temperature, initial monomer concentration, and degree of neutralization of AA, amount of crosslinker, initiator, and sodium humate were investigated. The superabsorbent composite was characterized by scanning electron microscopy, and the graft copolymerization reaction of AA on sodium humate micropowder was characterized by IR spectroscopy. Results obtained from this study show that the water absorbency of the superabsorbent composite synthesized under optimal conditions for synthesis with a sodium humate content of 5.3% exhibited absorption of 684 g H2O/g sample in distilled water. Water‐retention in soil is enhanced by the use of the superabsorbent composite. The effect of superabsorbent composite on the growth of corn is reported. The superabsorbent composite may be of use as water management materials for agriculture purposes in desert and drought‐prone areas. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5137–5143, 2006
Rheological study of the curing kinetics of epoxy–phenol novolac resin
Authors: Auad Maria L. , Nutt Steven R. , Stefani Pablo M. , Aranguren Mirta I.
Published: September 2006

The curing reaction of an epoxy–phenolic resin under different conditions was monitored using rheological measurements. The evolution of viscoelastic properties, such as storage modulus, G′, and loss modulus, G″, was recorded. Several experiments were performed to confidently compare the rheological data obtained under varied curing conditions of temperature, catalyst concentration, and reactive ratios. The values of G′ measured at the end of the reactions (at maximum conversion) were independent of the frequency and temperature of the tests in the range of high temperatures investigated. The overall curing process was described by a second‐order phenomenological rheokinetic equation based on the model of Kamal. The effects of the epoxy‐to‐phenolic ratio as well as the curing temperature and the catalyst concentration were also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4430–4439, 2006
Effect of applied stress on the alkaline hydrolysis of poly(ethylene terephthalate) at 40°C: Relevance to medical textiles
Authors: Rahman Mashiur , East G. C.
Published: September 2006

Laboratory‐accelerated degradation tests have been conducted to understand the stability of high tenacity poly(ethylene terephthalate) (PET) as a result of exposure to stressful chemical environments when used as an implantable prosthesis. The experiments were conducted at 40°C to mimic normal physiological conditions. At various time intervals, samples were collected and evaluated for weight loss (%), mechanical properties, and changes in the surface structure. The mechanical properties that were specifically observed include: breaking load, tenacity, breaking strain, work of rupture, and modulus. For all PET fibers loss of work of rupture was the highest. An empirical formula was developed to estimate degradation behavior over time, though such a prediction cannot be verified without further research and observation. The transverse cracks formed on the stressed samples beyond the critical load in an alkaline environment at 40°C are similar to those found on the PET prosthetic grafts. The cracks in the experimental samples at 40°C and those recovered from human bodies both appear more ‘corallite in structures’ versus those at room temperature. Therefore, it is concluded that the arterial stress that the PET prosthetic graft encountered inside the human body was higher than the yield load of the fiber. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4814–4822, 2006
Preparation and characterization of alginate and hydroxyapatite‐based biocomposite
Authors: Parhi Purnendu , Ramanan A. , Ray Alok R.
Published: September 2006

In this article, we report a novel route for the preparation of alginate‐hydroxyapatite biocomposite. Hydroxyapatite has been nucleated on alginate chains by precipitation method to obtain a biomimetic artificial bone‐like composite. The composite was characterized by powder XRD, FTIR, TGA, DTA, and SEM to ascertain its phase homogeneity and particle size distribution. Hydroxyapatite particles on alginate matrix are around 500–1000 nm in diameter. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5162–5165, 2006
Morphology and mechanical properties of high‐impact polystyrene/elastomer/magnesium hydroxide composites
Authors: Chang Suqin , Xie Tingxiu , Yang Guisheng
Published: September 2006

Ternary composites of high‐impact polystyrene (HIPS), elastomer, and magnesium hydroxide filler encapsulated by polystyrene were prepared to study the relationships between their structure and mechanical properties. Two kinds of morphology were formed. Separation of elastomer and filler was found when a nonpolar poly[styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene] triblock copolymer (SEBS) was incorporated. Encapsulation of filler by elastomer was achieved by using the corresponding maleinated SEBS (SEBS‐g‐MA). The mechanical properties of ternary composites were strongly dependent on microstructure. In this study, the composites with separate dispersion structure showed higher elongation, modulus and impact strength than those of encapsulation structure. Impact‐fracture surface observation showed that the toughening mechanism was mainly due to the massive cavitation and extensive matrix yielding. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5184–5190, 2006
Effect of different carbon fillers on the properties of PP composites: Comparison of carbon black with multiwalled carbon nanotubes
Authors: Zhou Zhen , Wang Shifeng , Zhang Yong , Zhang Yinxi
Published: September 2006

Polypropylene (PP)/carbon composites were prepared via melt blending PP with carbon fillers, including multiwalled carbon nanotubes (MWNTs) and carbon black (CB). Field‐emission scanning electron microscopy was used to research the morphology and dispersion of fillers in the PP matrix. The electrical properties, mechanical properties, and crystallization behaviors of PP/carbon composites were also investigated. The results show that the influence of MWNTs on the properties of PP composites is different with CB, which can be ascribed to the structure and aspect ratio difference between MWNTs and CB. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4823–4830, 2006
Synthesis of water‐insoluble functional copolymers containing amide, amine, and carboxylic acid groups and their metal‐ion‐uptake properties
Authors: Rivas Bernabé L. , Villegas Sandra , Ruf Beatriz
Published: September 2006

The crosslinked poly[N‐(3‐dimethylamino)propylmethacrylamide] [P(NDAPA)] and poly[N‐(3‐dimethylamino)propylmethacrylamide‐co‐acrylic acid] [P(NDAPA‐co‐AA)] were synthesized by radical polymerization. The resins were completely insoluble in water. The metal‐ion‐uptake properties were studied by a batch equilibrium procedure for the following metal ions: silver(I), copper(II), cadmium(II), zinc(II), lead(II), mercury(II), chromium(III), and aluminum(III). The P(NDAPA‐co‐AA) resin showed a lower metal‐ion affinity than P(NDAPA), except for Hg(II), which was retained at 71% at pH 2. At pH 5, the resin showed a higher affinity for Pb(II) (80%) and Cu(II) (60%), but its affinity was very low for Zn(II) and Cr(III). The polymer ligand–metal‐ion equilibrium was achieved during the first 20 min. By changing the pH, we found it possible to remove between 60 and 70% of Cd(II) and Zn(II) ions with (1M, 4M) HClO4 and (1M, 4M) HNO3. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5232–5239, 2006
Aspects of foaming a glass‐reinforced polypropylene with chemical blowing agents
Authors: Thompson M. R. , Qin X. , Zhang G. , Hrymak A. N.
Published: September 2006

This work explores the influence of a chemical blowing agent on different aspects of producing a short glass‐fiber‐reinforced polypropylene foam, examining the rheology of the system, the developed morphology of the part, and the resulting mechanical properties. Two different forms of an endothermic blowing agent, namely powder versus masterbatch, were compared to determine their effects on the process history and properties of an injection molded part. Samples were produced on an injection molding machine between 230 and 270°C using the low‐pressure foaming technique. Rheology of the resulting plasticized melt by the two different blowing agents was measured on an in‐line rheometer, showing a greater reduction in shear viscosity for the masterbatch additive, which correspondingly reduced the extent of fiber breakage observed. The final molded samples were analyzed for their foam structure (i.e., cell size, cell density, and skin thickness) as well as the properties of the glass fibers incorporated (namely, fiber length distribution). Tensile properties were found to diminish with increasing blowing agent content, though differences were observed based on the type of CBA used despite the similarities in foam structure produced. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4696–4706, 2006
Viscose fiber/polyamide 12 composites: Novel gas‐phase method for the modification of cellulose fibers with an aminosilane coupling agent
Authors: Paunikallio T. , Suvanto M. , Pakkanen T. T.
Published: September 2006

The objective of this study was to improve the adhesion between viscose fibers and polyamide 12 and, thereby, the mechanical properties of the corresponding composites. The cellulose fiber surface was chemically modified in the vapor phase with a silyl coupling agent, aminosilane [(3‐aminopropyl) triethoxysilane]. This new gas‐phase treatment for cellulose fibers proved to be highly effective. Relative to composites without the coupling‐agent treatment, the tensile strength of the composites (40/60 wt % fiber/polymer) increased from 49.3 to 87.4 MPa; the improved adhesion between the fibers and matrix induced by the coupling agent was observed under a scanning electron microscope. The presence and bonding of the coupling agent on the fibers after the reaction was confirmed by solid‐state 29Si‐NMR. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4478–4483, 2006
Improving rheological property of polymer melt via low frequency melt vibration
Authors: Li Youbing , Shen Kaizhi , Zhan Jie
Published: September 2006

A pulse pressure was superimposed on the melt flow in extrusion, called vibration extrusion. A die (L/D = 17.5) was attached to this device to study the rheological properties of an amorphous polymer (ABS) and semicrystalline polymer (PP, HDPE), prepared in the vibration field, and the conventional extrusion were studied for comparison. Results show that the melt vibration technique is an effective processing tool for improving the polymer melt flow behavior for both crystalline and amorphous polymers. The enhanced melt rheological property is also explained in terms of shear thinning criteria. Increasing with vibration frequency, extruded at constant vibration pressure amplitude, the viscosity decreases sharply, and so does when increasing vibration pressure amplitude at a constant vibrational frequency. The effect of vibrational field on melt rheological behavior depends greatly on the melt temperature, and the great decrease in viscosity is obtained at low temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5292–5296, 2006
Growth control and long‐range self‐assembly of poly(methyl methacrylate) nanospheres
Authors: D'Amato Rosaria , Venditti Iole , Russo Maria Vittoria , Falconieri Mauro
Published: September 2006

A systematic investigation of the reaction time and role of a cosolvent (toluene) in inducing several beneficial effects on nanobead properties was performed to achieve the synthesis of poly(methyl methacrylate) nanospheres. In particular, good dimensional control in the range of 100–400 nm, very low polydispersity, and a spherical shape were consistently obtained. Different parameters affecting the self‐assembly mechanism leading to the deposition of hard‐sphere photonic crystals were studied, and the features underlying their role were examined. Photonic crystals were produced by the evaporation of nanosphere suspensions at different temperatures, relative humidities, and suspension ionic strengths and with different substrate materials. The proper conditions for obtaining large crystal domains were determined. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4493–4499, 2006
Chemical modification of calcium alginate gel beads for controlling the release of insect repellent N,N‐diethyl‐3‐methylbenzamide
Authors: Xiao Congming , Zhou Mi , Lin Xiaodong , Li Ruqiong
Published: September 2006

Calcium alginate gel beads containing insect repellent N,N‐diethyl‐3‐methylbenzamide (CAGBDs) were modified via grafting copolymerization with a vinyl monomer. CAGBDs (5 g) were initiated with 8.5 × 10−2 mol/L potassium persulfate and 7.0 × 10−2 mol/L sodium bisulfite at the ambient temperature for 10 min, and then 6.22 mol/L acrylonitrile was added in droplets; the mixture was allowed to react at the same temperature for another 30 min. The effects of reaction conditions such as the stirring speed and monomer concentration on the modification of CAGBDs were investigated. Scanning electron microscopy analysis showed that the surface of modified CAGBDs was compact enough to keep N,N‐diethyl‐3‐methylbenzamide from touching. The release rate of N,N‐diethyl‐3‐methylbenzamide from modified CAGBDs was slower than that from unmodified CAGBDs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4850–4855, 2006
Optimization of the electron‐beam‐lithography parameters for the moth‐eye effects of an antireflection matrix structure
Authors: Kuo Chung‐Feng Jeffrey , Tu Hung‐Min , Su Te‐Li
Published: September 2006

In this study, we mainly used the characteristics of electron‐beam lithography in measurement control and direct‐write technology to improve the physical restrictions and production processes of optical lithography and other nanopattern production methods. We did this by using a silicon wafer as a substrate, coating a negative‐tone photoresist, and using scattering and the reflection produced by the collision of an electron beam with the wafer lattice and the proximity effect of a secondary electron inside the electron‐beam photoresist to produce an antireflection matrix structure with a moth‐eye effect. In addition, we used the Taguchi quality method with an orthogonal array to plan the experiment and the signal‐to‐noise ratio to analyze the experimental data, and in the experimental process, we produced a full factorial equivalent experiment, using very few experiment repetitions and deriving optimum conditions. Also, we used back‐propagation neural networks to fine‐tune significant factors, allowing the production of the deepest process control parameters and thereby imparting to the antireflection matrix structure the best effect. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5303–5313, 2006
Studies on grafting of acrylic acid onto polypropylene melt‐blown nonwovens induced by electron‐beam preirradiation
Authors: Cheng Bowen , Jiao Xiaoning , Kang Weimin
Published: September 2006

We report the graft copolymerization of acrylic acid onto the polypropylene (PP) melt‐blown nonwovens induced by electron beam (EB) preirradiation in this article. The occurrence of the graft copolymerization was confirmed by means of XPS, FTIR, and SEM. The effects of preirradiation dose, monomer concentration, bath ratio, reaction time, and temperature on the graft ratio were investigated. The water conservation, water absorption rate, and K+ exchange capacity were also determined on the grafted PP melt‐blown nonwovens, which showed that EB preirradiation‐induced grafting was an effective way to improve the hydrophicility of PP melt‐blown nonwovens. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4971–4977, 2006
Influence of thermal aging on the electrical properties of poly(vinyl chloride)
Authors: Nedjar M. , Béroual A. , Boubakeur A.
Published: September 2006

This article reports on the study of the thermal aging of poly(vinyl chloride) (PVC) used in medium‐ and high‐voltage cables. It is shown that the thermal aging leads to the degradation of the material and to the modification of its electrical properties. The degradation is all the more important and faster as the temperature is high. This degradation is attributed to a progressive evaporation of the plasticizer at the beginning of aging and to a weight loss of stabilizer followed by a change in the color of polymer and a release of hydrochloric acid at more advanced stages of aging. It also results in a crosslinking of the material and a shrinking of samples. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4728–4733, 2006
Controlled release formulations of carbaryl based on copper alginate, barium alginate, and alginic acid beads
Authors: Şanlı Oya , Işıklan Nuran
Published: September 2006

A controlled release system for reducing environmental impact was produced by encapsulating the pesticide carbaryl (Carb) in the alginate beads. The various bead formulations were prepared by using sodium alginate (NaAlg) as a polymer, CuCl2, BaCl2 as a crosslinking agent, and HCl as a linking agent. The surface morphology of prepared beads was characterized with scanning electron microscopy (SEM). SEM confirmed the spherical nature and surface morphology of the particles. Bead characteristics, such as Carb entrapment efficiency, particle size, swelling degree, and Carb release kinetics, were determined. The effects of crosslinker or linker concentration, type, and carbaryl/sodium alginate (Carb/NaAlg) ratio on Carb release from the beads were investigated for 20 days at 25°C. It was observed that Carb release from the beads increased with the increase of Carb/NaAlg ratio whereas decreased with the increase of crosslinker concentration. At the end of 20 days, the Carb release from alginic acid beads was found to be higher than that of copper alginate (Cu‐Alg) and barium alginate (Ba‐Alg) beads. The swelling measurements of the beads supported the release results. Release kinetics were described by Fickian and non‐Fickian approaches. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4245–4253, 2006
Application of copolymeric particulates for oilwell in‐depth performance control
Authors: Lu Hongsheng , Huang Zhiyu , Chen Qaunsheng , Wang Jian , Feng Yujun
Published: September 2006

The properties of two copolymeric particulates used for oilwell in‐depth performance control were investigated systematically. The lab‐scale studies showed that the average diameter of these particulates (E5 and G6) is 77.76 μm with the standard deviation of 2.16%. The two particulates exhibit good dilatability when immersed in 20 × 104 mg/L NaCl solution. Their capability of water retention (150 days) was 90% at 80°C. In addition, they exhibited good injectivity, driving performance and plug, and satisfied toughness index. The diffluence experiments confirmed that the coefficient of the profile modification were 85.7, 98.7, 86.1, and 98.1% when the permeability levels were 4.05 and 15.0, respectively. When using the two particulates, the average recovery ratio can reach 21%. The procedures mentioned earlier could be used as industry criteria to evaluate all kinds of particulate used as in‐depth performance controllers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5330–5335, 2006