bluuebunny/crossref_metadata_2025 huggingface dataset:
Point-of-care coagulation testing for reducing in-hospital delay in thrombolysis
Authors: Han Jung Hee , Jang Seongsoo , Choi Mi-Ok , Yoon Mi-Jeong , Lim Seung-Bok , Kook Jeong-Ran , Kang Dong-Wha , Kwon Sun U , Kim Jong S , Jeon Sang-Beom
Published: September 2018

Background:

The confirmation of prothrombin time international normalized ratio by a central laboratory often delays intravenous thrombolysis in patients with acute ischemic stroke.

Objectives:

We investigated the feasibility, reliability, and usefulness of point-of-care determination of prothrombin time international normalized ratio for stroke thrombolysis.

Methods:

Among 312 patients with ischemic stroke, 202 who arrived at the emergency room within 4.5 h of stroke onset were enrolled in the study. Patients with lost orders for point-of-care testing for the prothrombin time international normalized ratio or central laboratory testing for the prothrombin time international normalized ratio (n = 47) were excluded. We compared international normalized ratio values and the time interval from arrival to the report of test results (door-to-international normalized ratio time) between point-of-care testing for the prothrombin time international normalized ratio and central laboratory testing for the prothrombin time international normalized ratio. In patients who underwent thrombolysis, we compared the time interval from arrival to thrombolysis (door-to-needle time) between the current study population and historic cohort at our center.

Results:

In the 155 patients included in the study, the median door-to-international normalized ratio time was 9.0 min (interquartile range, 5.0–12.0 min) for point-of-care testing for the prothrombin time international normalized ratio and 46.0 min (interquartile range, 38.0–55.0 min) for central laboratory testing for the prothrombin time international normalized ratio (p < 0.001). The intraclass correlation coefficient between point-of-care testing for the prothrombin time international normalized ratio and central laboratory testing for the prothrombin time international normalized ratio was 0.975 (95% confidence interval: 0.966–0.982). Forty-nine of the 155 patients underwent intravenous thrombolysis. The door-to-needle time was significantly decreased after implementation of point-of-care testing for the prothrombin time international normalized ratio (median, 23.0 min; interquartile range, 16.0–29.8 vs median, 46.0 min; interquartile range, 33.5–50.5 min).

Conclusion:

Utilization of point-of-care testing for the prothrombin time international normalized ratio was feasible in the management of patients with acute ischemic stroke. Point-of-care testing for the prothrombin time international normalized ratio was quick and reliable and had a pivotal role in expediting thrombolysis.
SATB2 and Hep Par 1 Immunohistochemistry Is Helpful in Distinguishing Between Inflamed and Architecturally Altered Ileal Pouch and Rectal Cuff Mucosa
Authors: Groisman Gabriel , Cai Zhenjian , Sabo Edmond , Harpaz Noam
Published: September 2018

The management of patients with ulcerative colitis after proctocolectomy with ileal pouch-anal anastomosis includes independent histological assessments of inflammation in the ileal pouch and the rectal cuff. However, the distinction between pouchitis and cuffitis can be impeded both endoscopically and histologically by the combined effects of inflammation and regeneration. We investigated the use of 2 markers, hepatocyte paraffin 1 (Hep) and SATB2 (special AT-rich sequence-binding protein 2), which are expressed immunohistochemically in the small and large bowel epithelium, respectively, as ancillary methods to deal with this problem. Immunohistochemical staining was performed retrospectively on 20 consecutive pairs of post–ileal pouch-anal anastomosis biopsies with varying degrees of histological inflammation and architectural distortion, which had each been designated as “ileal pouch” or “rectal cuff” by the referring endoscopists. Expression was graded as focal (10% to 74% stained cells) or diffuse (75% to 100%). Among the ileal pouch biopsies, 20 (100%) expressed Hep either diffusely (75%) or focally (25%), whereas SATB2 staining was either negative in 15 (75%) or focal in 5 (25%), the latter group all expressing Hep diffusely. Among the rectal cuff biopsies, 14 expressed SATB2 diffusely. Of these, Hep was either negative in 11 (79%) or focally positive in 3 (21%), the latter group all expressing SATB2 diffusely. Six ostensibly rectal cuff biopsies (30%) expressed Hep diffusely and were negative for SATB2, suggesting endoscopic misidentification. None of the 40 biopsies expressed both markers diffusely. We conclude that in doubtful cases, diffuse expression of either Hep or SATB2 can be helpful in discriminating between ileal pouch and rectal cuff mucosa, respectively.
Instructional Feedback: An Effective, Efficient, Low-Intensity Strategy to Support Student Success
Authors: Oakes Wendy Peia , Lane Kathleen Lynne , Menzies Holly M. , Buckman Mark Matthew
Published: September 2018

Instructional feedback is a practical strategy for monitoring student learning in response to instruction and providing prompts to students to confirm, refine, or clarify their misunderstandings. In this article, we describe a step-by-step process for using instructional feedback, with teaching tips to assist successful implementation with all students, including those with emotional and behavioral disorders. Throughout the article, we offer lessons from practitioners who have successfully used instructional feedback in their classrooms.
Peer Victimization in Children With ADHD: A Community-Based Longitudinal Study
Authors: Efron Daryl , Wijaya Michell , Hazell Philip , Sciberras Emma
Published: September 2018

Objectives: To investigate (a) whether children with ADHD experience higher levels of overt and relational peer victimization (PV) than children without ADHD and (b) child, family, and school predictors of PV in children with ADHD. Method: 173 children with ADHD and 199 non-ADHD controls were recruited through 43 Melbourne schools at mean age 7.3 years. Parent- and teacher-reported PV (Social Experience Questionnaire) data were collected at mean age 8.9 years. Potential child, family, and school predictors of PV were measured at baseline. Results: Children with ADHD experienced higher levels of PV than children without ADHD by both parent- and teacher-report. Child predictors accounted for the greatest variance in PV, and the strongest predictors of PV were teacher-reported conduct problems, and medication use. Conclusion: Children with ADHD are at higher risk of PV compared with non-ADHD controls. Recognizing and addressing PV is important to reduce additional impairment in children with ADHD.
Sandwich shield subjected to bird impact: Use of surrogate models for influencing parameter analysis and shield behaviour understanding
Authors: Wilhelm Arnaud , Rivallant Samuel , Ferrero Jean-François , Morlier Joseph
Published: September 2018

In this work, the behaviour of a sandwich shield subjected to a 1.82 kg bird impact at 175 m/s is studied using a finite element model. The 6 most influential design parameters are varied and their effects on the shield behaviour and on the target protection are assessed. First, we try to establish an engineer's visualization by varying parameters 2 × 2 using three 5-levels full-factorial design of experiments. These three 2D design of experiments enable us to visualize precisely the different effects of each parameter. Then a full sensitivity analysis (6D) is performed using a Latin Hypercube sampling to assess the possible interactions between parameters. Surrogate models are constructed using the Gaussian Process framework to follow the variation of the outputs in the 6D design space. These surrogate models are finally studied using two statistical methods: the Sobol′ method and the Morris method. The methodology developed in this study enables to improve the understanding of the behaviour of a shield under a soft body impact, as a first step towards a shield design tool.
Evaluation of sandwich panels with composite tube-reinforced foam core under bending and flatwise compression
Authors: Cinar Kenan
Published: September 2018

In some applications such as roofs and walls, it is important to supply low thermal conductivity and high bending stiffness to structures. Generally, foam materials are preferred, which have low thermal conductivity. However, bending stiffness and compression properties of foam materials are low. In this study, composite tubes were inserted to the foam core material to improve the compression and bending properties of the sandwich structure. Vacuum infusion method was used to manufacture the sandwich structure. The bending and compression performance of the structures with and without composite tubes were compared. To measure the bending stiffness and compression properties of the structure, three-point bending and compression tests were conducted according to American Society for Testing and Materials (ASTM) standards. The manufacturing procedure can be easily automated and applied to large and complex shape panels. In addition, a parametric analysis was done to investigate the effect of the number of tubes and the diameter of the tubes on bending and compression stiffness of the structure. According to the test results, the samples including the composite tubes gave six times higher bending stiffness as compared to the samples without the composite tubes. As the diameter of the tubes increased the bending stiffness and the ultimate core shear strength increased. In addition, the structures including 14 mm diameter tubes had higher specific absorbed energy values under compression loading.
A Prefigurative Politics of Play in Public Places: Children Claim Their Democratic Right to the City Through Play
Authors: Carroll Penelope , Calder-Dawe Octavia , Witten Karen , Asiasiga Lanuola
Published: September 2018

Children have as much “right” to the city as adult citizens, yet they lose out in the urban spatial justice stakes. Built environments prioritizing motor vehicles, a default urban planning position that sees children as belonging in child-designated areas, and safety discourses, combine to restrict children’s presence and opportunities for play, rendering them out of place in public space. In this context, children’s everyday appropriations of public spaces for their “playful imaginings” can be seen as a reclamation of their democratic right to the city: a prefigurative politics of play enacted by citizen kids. In this article, we draw on data collected with 265 children in Auckland, Aotearoa/New Zealand, to consider how children’s playful practices challenge adult hegemony of the public domain and prefigure the possibilities of a more equal, child-friendly, and playful city.
The most-common phrasal verbs with their key meanings for spoken and academic written English: A corpus analysis
Authors: Liu Dilin , Myers Daniel
Published: September 2018

English phrasal verbs (PVs) are ubiquitous and often polysemous. These lexical items are thus very important, but also challenging for ESL/EFL learners. Substantial research that can inform instructional approaches to PVs has already been conducted. One strand of this research has focused on identifying PVs that merit prioritization in learning. For example, Garnier and Schmitt (2015) developed a list of the most frequent meanings expressed by the 150 most common PVs. The present study extends their work by examining and comparing the meaning distributions of the 150 most common PVs in spoken English and in academic writing, arguably the two registers that ESL/EFL learners study the most. Using the spoken sub-corpus and the written academic sub-corpus of the Corpus of Contemporary American English, the study evaluates whether the proportional frequencies of PVs’ meanings vary across the two registers. The results show a significant cross-register difference in an overwhelming majority of the 150 most common PVs. The findings suggest that instructional approaches to PVs should indeed prioritize different meanings of PVs depending on the kind of register learners engage with. A list of the PVs with their main meanings in each of the two registers is made available as an online supplement .
Probabilistic assessment of plan-asymmetric structures under the near-fault pulse-like events considering soil–structure interaction
Authors: Birzhandi Mohammad S , Halabian Amir M
Published: September 2018

This study aims to evaluate the torsional effects and soil–structure interaction simultaneously under near-fault pulse-like earthquakes in a probabilistic framework. Incremental dynamic analysis and fragility curves are employed for this goal. An eight-story R/C dual lateral load-resistant building consisting of shear walls and moment resisting frames is used. The median incremental dynamic analysis curves reported the maximum capacity for the symmetric structure in each foundation conditions. In addition, the capacity of structure will be increased when more shear wave velocity is assumed. Therefore, from this view, neglecting the soil–structure interaction will not be in the safe side. Fragility curves (using intensity measure directly) show that for different cases (except for very low shear wave velocity), more value of eccentricity leads to more probability of collapse. Moreover, the fragility curves show that (for each eccentricity), soil–structure interaction effect is significant only for the flexible base structure with the very low shear wave velocity (100 m/s) and more eccentricity value leads to less soil–structure interaction effects. Results show that the significant eccentricity value may lead to reduce the soil–structure interaction effect in the shear-wall structures under the near-fault events.
Toward a typology of young produsers: Teenagers’ transmedia skills, media production, and narrative and aesthetic appreciation
Authors: Guerrero-Pico Mar , Masanet Maria-Jose , Scolari Carlos A
Published: September 2018

Based on the qualitative analysis of data from workshops and interviews with teenagers from eight countries, this article aims to determine the degrees of productive, narrative, and aesthetic knowledge that teenagers put into practice when they create their media contents. From a theoretical framework that links teens, informal learning environments, and participatory cultures, the findings point toward three types of teenage produsers: casual, aspirational, and expert. Each type is representative of different aspects of production in terms of the types of media contents produced; the planning of the production process; the application of narrative and aesthetic values when creating; and the motivations behind the production. The study concludes with an invitation to rethink what participatory culture means in the light of teenagers’ production practices.
The multimodal interactional organization of tasting: Practices of tasting cheese in gourmet shops
Authors: Mondada Lorenza
Published: September 2018

Taste is a central sense for humans and animals, and it has been largely studied either from physiological and neurological approaches or from socio-cultural ones. This paper adopts another view, focused on the activity of tasting rather than on the sense of taste, approached within the perspective of ethnomethodology and multimodal conversation analysis. This view addresses the activity of tasting as it is interactionally organized in specific social settings, observed in a naturalistic way, on the basis of video recordings. Focusing on video recorded improvised tastings of cheese in gourmet shop encounters, the paper offers a systematic analysis of the way in which tasting is orderly achieved in an intersubjective way. It follows the various steps characterizing tasting, from the invitation to taste, to the grasping of a bit to taste, which is put in the mouth, chewed, and swallowed; it details how an interactional moment offering the taster a priviledged, individual, focused space in which to devote exclusive attention to the object tasted is actively tailored by all parties. By contrast, the completion of tasting is marked by a return to mutual gaze, the animation of facial expressions and nods, and the final production of a judgment of taste. By offering a systematic reconstruction of how these tasting moments are organized, the paper invites to a multimodal approach of sensoriality in social interaction.
Bacteria and the market
Authors: Campbell Norah , Deane Cormac
Published: September 2018

We present a psychoanalytic reading of 332 images of bacteria in advertising for antibacterial products and in public service announcements since 1848. We identify four dominant and recurring tropes that bring bacteria into the symbolic realm: cuteness, overpopulation, the lower classes and deviant sex. As a first stage of our analysis, we propose that bacteria are symptoms of a capitalist socio-economic order. Bacteria are repressed fears and fantasies about purity, gender, race, community, pollution, class and sexual promiscuity which are tacitly leveraged by antibacterial brands. We then ask why these fears and fantasies take the form of the bacterial. We trace a movement from the psychoanalytical concept of the symptom to the sinthome. If symptoms can be read as a repressed, extrinsic ideology that can/must be revealed, the sinthome is a fantasy that, when brought to light, does not dissolve, because it structures reality intrinsically. We indicate an emerging body of psychoanalytically informed critical marketing that points to the perverse effects of emancipatory, revelatory critical analysis, where the consumer is made to face their symptom. The sinthome is a useful way to summarize this problem. However, while the sinthome is testimony to the impossibility of redemption through the revelation of our ideological prisons, it has a productive, positive contribution to critical marketing theory. It presents a theory of and a tool for analysing fantasies that focus on the form of their expression, rather than their content. In our case, the fact that fantasy takes the form of the bacterial reveals a surprising confluence between the politics of community and the physiology of (auto)immunity, with important and specific strategies on how ideology can be interrupted. This power of the sinthome to straddle the symbolic, imaginary and real creates ways to conceive marketing phenomena as simultaneously psychoanalytic, political, physical and metaphorical.
Free Volume in Epoxide Oligomers
Authors: Koike Tsuneo
Published: September 2018

Free volume studies are reviewed for the oligomers of the diglycidyl ether of bisphenol-A (DGEBA) before cross-linking. The Williams-Landel-Ferry (WLF) method was used to analyse the macroscopic free volume in the DGEBA oligomers in comparison with that in the crosslinked DGEBA network. The crosslinked system has relatively large fractional free volume at the Tg. The DGEBA oligomers have bulky bisphenol-A structure. The cross-link sites in the network structure does not always provide a suitable environment for close packing of rigid molecules. The WLF type equations are applicable to the temperature dependencies of the melt viscosity, the dielectric relaxation time, and the ionic conductivity for the uncured DGEBA oligomer. These three viscoelastic properties are discussed in terms of the movements of three moving units: the chain segment, the dipole, and the ionic charge carrier. The mobility difference between the three moving units is clarified from the standpoint of the free volume concept.
New Peroxide Curable Perfluoroelastomer for High Temperature Applications
Authors: Comino G. , Arrigoni S. , Apostolo M. , Albano M. , Arcella V.
Published: September 2018

Perfluoroelastomers are used in hostile environments due to their very high chemical and thermal resistance. Halogen containing perfluoroelastomers are cured by peroxide in presence of a curing agent. Commonly used curing agents, such as triallyl cyanurate and triallyl isocyanurate, show good thermal resistance only up to 220°C, thus restricting material application at higher temperatures.

In this work, a new perfluoroelastomer for high temperature applications is presented. The polymer is synthesized with the so-called branching and pseudoliving technology and it is crosslinked with a new curing agent especially designed for high temperature resistance, namely a fluorinated di-olefin. The resulting polymer network exhibits by far improved thermal resistance, retaining its sealing ability and mechanical properties up to 300°C. Besides, the processability and the sealing properties of this di-olefin cured perfluoroelastomer are excellent. Based on this technology, a new peroxide curable perfluoroelastomer for high temperature applications has been obtained and developed at industrial scale. This material is today available from Ausimont S.p.A. with the trade name of “Tecnoflon® PFR95”.
A Thorough Examination of a Torsional Dynamic Rheometer with a Closed Oscillating Cavity
Authors: Leblanc Jean L. , Mongruel Anne
Published: September 2018

The so-called Rubber Process Analyser, RPA 2000®, is a torsional dynamic rheometer, whose test cavity design is similar to that of the Moving Die Rheometer, a well known rotorless vulcameter, and the only available device which offers the possibility to test very stiff materials, in dynamic conditions. The paper systematically investigates the test conditions prevailing in the instrument, with respect to basic rheology principles, in order to identify the possible sources of errors and to quantify them. Using a monodisperse polymer melt, an experimental comparison is made with conventional cone-and-plan rheometers and data obtained with the RPA are found similar. A numerical simulation of the instrument test cavity is made in order to evaluate the error associated with the closed rim and the associate pressurisation. Results obtained show that rheological functions can be evaluated with a confidence of around 10%.
Dielectric and Mechanical Properties of Rubber Ferrite Composites Containing Barium Ferrite
Authors: Soloman M. A. , Kurian Philip , Anantharaman M. R.
Published: September 2018

The incorporation of various types of ferrites in rubber matrixes leads to the development of rubber ferrite composites (RFC). These RFC have a large number of applications as flexible magnets, high-tech sensors, for telecommunication and radiowave absorbers. Both natural and synthetic rubber has the potential of being value added by the incorporation of ferrites. Applications like microwave absorbers warrant that these composites have an appropriate dielectric strength with the required magnetic property. This can be achieved by synthesizing composites based on natural rubber and ferrites. In this paper we report the synthesis of RFC containing barium ferrite according to a specific recipe and its evaluation of dielectric and mechanical properties.
Olefin Polymerisation Catalysts
Authors: Nowakowska M.
Published: September 2018

Polyolefins, which are products of polymerisation of unsaturated hydrocarbons of the olefin series, have a molecular weight in the range from several thousands to several millions. Depending on the type of monomer and method and mechanism of polymerisation the resulting polyolefins may differ in their structure and molecular weight. They can be used in many applications, for example as constructional plastics and in packaging, fibres, rubbers, and also as additives to control the viscosity of motor oils(1). As regards their scale of production polyolefins occupy the top position among mass-produced polymers(2).
Recycling of Polypropylene Based Car Bumpers: Mechanical and Morphological Analysis
Authors: Ragosta G. , Musto P. , Russo P. , Camino G. , Di Maio L.
Published: September 2018

The recycling of new and ten years old bumpers either painted or unpainted have been investigated. They were made by a polypropylene matrix and an ethylene-propylene rubber copolymer as dispersed phase. Mechanical testing carried out before reprocessing showed a dramatic loss in the tensile and impact properties of aged bumpers with respect to the new items. The recycling further reduces the mechanical performances of these items while it has only a little effect on the properties of new bumpers. The addition of appropriate stabilising agents, during the recycling process of aged bumpers, produced an enhancement of the whole mechanical parameters. In particular the impact strength reached values typical of very tough materials and close to those of new items. Scanning electron microscopy of the fracture surfaces showed a considerable enhancement of matrix plasticity when stabilisers were used.
Recycling of Glass Fabric Coated by Polyvinyl Chloride
Authors: Takahashi Tetsuya , Kimura Teruo
Published: September 2018

In order to stabilise recycled cutting waste of PVC coated glass fiber fabric (hereafter “PVC-GF”), a composite material having PVC as a matrix combined with hydrotalcite (hereafter “HT”) and zinc stearate (hereafter “ZS”) was prepared. The mechanical properties were measured and the inhibition effect of generating hydrogen chloride gas in heating was investigated.

Cutting waste of PVC-GF was subjected to heated compression molding under various conditions to prepare specimens, and the bending strength was measured. The results showed that as the temperature increased from 120°C to 150°C and as heating the time was extended from 20 minutes to 45 inutes, the bending strength was greatly increased. In bending deformation, glass fibers contained in the specimens showed an effective reinforcing effect.

The specimens combined with HT and ZS were obtained by injection molding. The starting time of generating hydrogen chloride gas in heat was investigated for the injection molded specimens. The result showed that the addition of both HT and ZS could greatly retard the time until hydrogen chloride gas was generated proving the benefits. Furthermore, the effect of UV irradiation on hydrogen chloride gas generation was investigated. It was clear that the starting time of hydrogen chloride gas generation was delayed by UV irradiation for the specimens with a relatively large amount (5-10 phr) of HT, as opposed to little change for the specimens with a relatively small amount (0-0.5 phr) of HT. This indicates that HT addition is effective for material recycling of PVC products used outdoors.
A Study of the Utilization of Reclaimed Natural Rubber Prophylactic in Blend with Epoxidized Natural Rubber and Silica
Authors: Mathew George , Singh R.P. , Groeninckx Gabriel , Thomas Sabu
Published: September 2018

On the basis of rubber rejects becoming a major environmental and social issue, scrap latex rejects must be considered as a potential candidate for recycling. This is because of the high quality and lightly crosslinked nature of the rubber hydrocarbon obtainable from such rejects. The authors have conducted a study of utilization of reclaimed natural rubber prophylactic in blend with epoxidised natural rubber with 50 mole% epoxidation (ENR-50) and silica. The vulcanization characteristics and dynamic mechanical analysis of the vulcanizates have been carried out. It has been observed that the optimum cure time shows a gradual decrease with natural rubber prophylactics as well as silica, indicating cure activation. The damping behaviour has been found to be strongly dependent on the presence of silica filler in the sample. The dynamic modulus values have been increased with the addition of silica, both below and above the glass transition region. Addition of natural rubber prophylactics as well as silica filler has been found to be increasing the glass transition temperature of epoxidised natural rubber. Increase in frequency also increases the glass transition temperature of epoxidised natural rubber. The analysis of the relative distribution of silica among the components of the mix reveals that a major portion of silica remains in the prophylactics phase while it can interact with the epoxy groups in epoxidised natural rubber phase. The evaluation and variation of network density in the vulcanizates carried out using storage modulus–temperature plots and solvent sorption method reveals an increasing trend with the addition of natural rubber prophylactics and silica filler. The energy of activation values show a decrease at 40 phr loading of natural rubber prophylactics after an initial increase at 10 phr loading. Addition of silica to epoxidised natural rubber/natural rubber prophylactics mixes have been found to be causing different variations in energy of activation values depending on the composition of the mix.
The Use of Rubber Scrap – Thermoplastic Compositions for the Production of Porous and Non-Porous Articles
Authors: Kowalska Ewa
Published: September 2018

The utilisation of comminuted vulcanised rubber scrap as filler for thermoplastic compositions (in some cases with mineral fillers) was investigated. The structure of compositions and their use depends on the formulation and method of moulding. The more rubber scrap in the composition, the more porous the structure of articles obtained. The use of pressure methods of moulding of compositions (injection moulding, pressure moulding, extrusion with pressure calibration) produce either non-porous articles, or porous articles with a non-porous skin. The use of non-pressure method of moulding (extrusion without calibration) produces porous articles with open pores. The result of the investigation shows that the use of polyolefins and poly(vinyl chloride) (original or secondary) is profitable.
Modification of Isophthalic Unsaturated Polyester Resin using Elastomers Bearing Reactive Functional Groups
Authors: Benny Cherian. A , Thachil Eby Thomas
Published: September 2018

Isophthalic unsaturated polyester resins are used widely as the thermoset matrix for high quality fibre-reinforced composites. However, they suffer from low impact resistance. Substantial enhancement of the fracture toughness of brittle polymers may be achieved by dispersing rubber particles in the polymer matrix. In this study, elastomers bearing reactive functional groups, viz. hydroxy terminated polybutadiene (HTPB), hydroxy terminated natural rubber (HTNR), epoxidised natural rubber (ENR), amino terminated natural rubber (ATNR), carboxy terminated butadiene-acrylonitrile rubber (CTBN) and maleated nitrile rubber (MA-g-NBR) were blended with isophthalic resin. The physical properties of the cured blends were compared with those of the unmodified resin. The elastomers bearing reactive functional groups showed compatibility with the resin and improved the toughness and impact resistance of the cured resin substantially. The performance of maleic anhydride-grafted nitrile rubber was found to be far superior to all other rubbers considered in this investigation. An improvement in toughness, impact resistance and tensile strength has been achieved without seriously affecting any other property.
Properties of Recycled Poly(vinylchloride)/ Acrylonitrile-Butadiene Rubber Blends: The Effect of Maleic Acid
Authors: Ghani Supri A. , Ismail H. , Yusof A.M.M
Published: September 2018

Maleic acid (MAc) was used to improve the compatibility of recycled poly(vi nylchloride)(PVCr)/acrylonitrile-butadiene rubber (NBR) blends. Virgin PVC (PVCv) blends with NBR were also prepared for comparison. The blends were melt mixed using a Haake Rheomix Polydrive R 600/610 at 150 °C and a rotor speed of 50 rpm. It was found that the maleic acid significantly improved the PVCr/NBR blends properties. At a similar blend composition, the PVCr/NBR + MAc blends exhibited a higher peak stress and a higher stress at 100% elongation (M100) but a lower elongation at break and a lower swelling index than ordinary PVCr/NBR blends. Scanning electron microscopy (SEM) of the tensile fracture surfaces of the blends indicated that the maleic acid increased the interfacial interaction between the PVCr and NBR phases, thus improving their compatibility. Differential scanning calorimetry (DSC) indicated that the PVCr/NBR with MAc incorporated had a higher Tg than the PVCr/NBR and PVCv/NBR blends.
Recycling of Edible Oil Pouches: Composition and Thermal Stability
Authors: Choudhury Arup , Mukherjee Mandira , Adhikari Basudam
Published: September 2018

Recycled polyethylene containing very small amounts of nylon-6 or PET, which is the source of flexible oil pouches, may find applications as raw materials for other polymer products after the recycled polymer is properly identified and characterized before reprocessing. Proper identification and characterization of the polymer components present in the waste has considerable importance for obtaining value-added products. In this investigation, post-use oil pouch films, collected from municipal garbage, were first subjected to sorting, washing and drying. Then the dried films were fractionated by dissolving in solvents. The isolated component polymers were characterized and identified by solvent fractionation, FTIR, DSC-TGA and WAXD analysis.
Blends of Nylon 6/66 and Acrylonitrile-Butadiene Rubber: Effects of Blend Ratio and Dynamic Vulcanization on Morphology and Properties
Authors: Kumar C. Radhesh , Aravind I. , Stephan R. , Koshy Peter , Jose J. , Radusch H. J. , Michler G.H. , Reghunatha Varma R. , Thomas Sabu
Published: September 2018

The morphology and mechanical properties of nylon (copolyamide 6/66)/ acrylonitrile-butadiene rubber (NBR) blends have been studied with special reference to the effect of blend ratio and crosslinking systems. Morphological investigations of the blends using scanning and transmission electron microscopies show that a uniform and finer dispersion of the elastomer phase is achieved by dynamic crosslinking. The effects of various crosslinking systems such as sulphur and dicumyl peroxide on the morphology and mechanical properties of these blends were analysed. Morphological stability of the blends upon annealing has been investigated and the mechanical properties of the blends have been discussed. Attempts have been made to correlate the morphology with the mechanical properties of the dynamically vulcanized blends. The stability of the blend morphology during annealing has been examined.
Devulcanization of Automobile Scrap Tyres by a Mechanochemical Process
Authors: Jana G.K. , Das C.K.
Published: September 2018

The de-vulcanization of rubber waste poses a challenging economical, environmental and social problem. We propose a new de-vulcanization process to re-use the rubber waste. It is a mechano-chemical process (MCP), where the waste is de-vulcanized by a combination of mechanical shearing, heat (110 °C) and the use of a de-vulcanizing agent (diallyl disulfide). A new look at the de-vulcanization mechanism and the influence of the de-vulcanizing agent on the mechanical properties of the ultimate re-vulcanized rubber is also presented. One of the most interesting observations is that the retention of tensile strength of the re-vulcanized rubber with respect to the original tyre was 34.9% when de-vulcanized in the absence of diallyl disulfide and 72.4% in its presence. The formation of extra crosslinks in those re-vulcanized rubbers containing disulfide was confirmed from crosslink density data and from TGA results. DMA analysis revealed that the storage modulus also increased for re-vulcanized rubber containing the disulfide.
Thermoplastic Vulcanizates (TPVS) Based on Silicone Rubber and Ethylene Butene Copolymer: Study at a Fixed Blend Ratio
Authors: Basuli U. , Chaki T. K. , Naskar K.
Published: September 2018

Thermoplastic vulcanizates (TPVs) or dynamic vulcanizates are a special class of thermoplastic elastomers, produced by simultaneously mixing and crosslinking a rubber with a thermoplastic polymer. Ethylene-butene copolymers are nowadays gaining more importance over ethylene-octene grades due to economic reason. TPVs based on blends of silicone rubber and ethylene-butene thermoplastic copolymer at a fixed blend ratio have been prepared via dicumyl peroxide (DCP) crosslinking. These TPVs exhibit very good overall mechanical properties. With increasing concentration of DCP, tensile strength, modulus, elongation at break and hardness of TPVs increase whereas tension set values decrease. Oscillating Disc Rheometer (ODR) delta torque values are correlated with various physical properties of TPVs. Ageing characteristics and recyclability of these silicone-based TPVs are also reasonably good. Rheological studies confirm pseudoplastic nature of these materials. SEM photomicrographs of theses silicone based TPVs confirm dispersed phase morphology.
Preparation of in situ Precipitated Silica Filled Acrylonitrile Butadiene Rubber Composites
Authors: Maya K.S. , Rani Joseph
Published: September 2018

Acrylonitrile Butadiene Rubber (NBR) was reinforced with silica by the in situ precipitation. Silica was prepared in the NBR latex by using sodium silicate and ammonium chloride. The latex was then coagulated, dried properly and compounded on a mixing mill with other compounding ingredients. Mixes containing conventional silica of the same concentration was also prepared for comparison. All the compounds were vulcanised up to their optimum cure times. Mechanical properties are found to be superior for vulcanizates containing in-situ precipitated silica. The nitrile rubber-silica composite prepared by the novel method shows better properties and improved rubber – filler interaction.
Potential Applications of Polystyrene in Optoelectronics
Authors: Sureshkumar M.S. , Goyal R.K. , Negi Y.S.
Published: September 2018

Organic polymer based materials are becoming the workhorse in the area of photonics and optoelectronics. These materials are rapidly replacing their inorganic counter parts due to their flexibility in manufacturing combined with the ease in fabrication and manufacturing. Polystyrene, being a low cost commercial commodity plastic material has been utilized as one of the important polymeric material for various NLO active devices. Guest-Host systems based on polystyrene and NLO active chromophores have been extensively studied. As a host polymer it can easily accommodate the NLO guest molecules by simple modification by solution casting and other processes. Thus, polystyrene based NLO active systems offers a relatively cost-effective NLO active systems.

Recent investigations have confirmed the suitability of disposable recycled polystyrene as a host polymer to accommodate NLO active chromophores that can lead to dirt-cheap NLO active device materials.

This review summarizes the applications of polystyrene based materials in the area of Optoelectronics. The fundamental aspects pertaining to Guest-Host NLO chromophore is also discussed. Some of the recent investigation about the usage of recycled polystyrene system is highlighted.
Use of Sawdust in Polyethylene Composites
Authors: Hillig É. , Freire E. , Zattera A.J. , Zanoto G. , Grison K. , Zeni M.
Published: September 2018

In this study, composites were made with wood sawdust residues and a polyolefin. Experiments were carried out in order to analyze different parameters for processing the composites. The parameters analyzed were the sawdust/polymer ratio and the type of coupling agent. The sawdust and the polymer were mixed in a single extruder in order to produce profiles. The results showed that the composites made of HDPE and sawdust had good mechanical properties, suitable for industrial applications. These results, together with the availability of the residues in the northeast of Rio Grande do Sul state, (Brazil), makes these composites a good alternative for the use of residues.
Studies on Comparison of Electrical Properties of Nanoclay Reinforced EPDM-g-TMEVS/PS and EPDM-g-TMEVS/PMMA Blends
Authors: Ramar P. , Alagar M.
Published: September 2018

A novel graft copolymer of tris(2-methoxyethoxy) vinylsilane grafted ethylene-propylene-diene terpolymer (EPDM-g-TMEVS) has been developed by grafting of tris(2-methoxyethoxy) vinylsilane (TMEVS) onto EPDM using dicumyl peroxide (DCP) as radical initiator in a twin screw extruder. The linear polystyrene and polymethylmethacrylate blends based on EPDM-g-TMEVS have been synthesized with varying weight percentages of polystyrene (PS) and polymethylmethacrylate (PMMA) by melt mixing in a twin-screw extruder. The dynamically vulcanized and nanoclay reinforced blends of EPDM-g-TMEVS/PS and EPDM-g-TMEVS/ PMMA were developed by using DCP and organically modified montmorillonite clay in a twin-screw extruder. The linear, dynamically vulcanized and nanoclay reinforced EPDM-g-TMEVS/PS and EPDM-g-TMEVS/PMMA blends have been characterized by different experimental studies to assess their suitability for cable insulation applications. The effect of incorporation of TMEVS grafted EPDM on electrical properties such as volume resistivity, surface resistivity, arc resistance and dielectric strength of EPDM-g-TMEVS/PS and EPDM-g-TMEVS/ PMMA blends have been studied. The values of volume resistivity, surface resistivity, arc resistance and dielectric strength are increased with increasing percentage concentration of EPDM-g-TMEVS due to the presence of -Si-O-Si-linkages. The blends filled with nanoclay exhibit improved electrical properties due to the presence of inorganic moiety, which in turn enhance the insulation behavior. However, among the hybrid polystyrene and polymethylmethacrylate thermoplastic blends studied in the present investigation, EPDM-g-TMEVS/PS blends possess better insulating behavior than that of EPDM-g-TMEVS/PMMA blends due to thermally stable -Si-O-Si- linkages, hydrophobic and non-polarnature. The XRD studies were also carried out to confirm the formation of nanoclay reinforced blends. From the results, it was ascertained that the clay intercalation occurred in the case of polystyrene blends whereas clay intercalation with some degree of exfoliation occurred in the case of PMMA blends.
Chemically Modified Carbon Black Filled Ethylene-Propylene-Diene Rubber Composites: Mechanical and Dynamic Mechanical Study
Authors: Sini N.K. , Choudhury Arup , Sarkhel Gautam
Published: September 2018

A surface-modified carbon black (N330) has been prepared by treating it with pentaerythitol, combination of pentaerythitol and pyrogallol and a combination of pentaerythitol and resorcinol in aqueous solution at different molar concentrations. The adsorption of modifier and formation of new functional groups could be identified from the FTIR peaks. This modified carbon black has been used as one of the compounding ingredients in EPDM rubber. It was found that carbon black modified with pentaerythitol and resorcinol showed more pronounced effect than the other two. In all cases the properties like hardness, tensile strength, and modulus are found to be increasing as the concentration of modifier was increased. All these values are higher as compared to rubber compound with unmodified carbon black. While the properties like abrasion loss, compression set, elongation at break, tan delta were found to be decreasing with increase in modifier concentration. All these results points towards an improved interaction between the filler and rubber. The surface functional groups on the modified carbon black would attach to the rubber chains and will act as secondary cross linker. Calculated values of crosslink density were found to be increasing with the modifier concentrations, clearly defines the formation of secondary crosslinking.
Effect of Modified Carbon Black on the Processing of NR- and SBR-based Compounds
Authors: Adhikary Abhijit , Sengupta Pranab Kumar , Mukhopadhyay Rabindra
Published: September 2018

A simple technique adopted in the laboratory is able to attach flexible, long-chain, aliphatic, fatty acid moiety on the surface of reinforcing carbon black N330. Modified blacks show less bound rubber by comparison with the control, but their better dispersibility effectively outweighs any reduction in polymer–filler interaction resulting from the smaller available surface area. When subjected to strain sweep, compounds containing modified blacks show a slower reagglomeration rate of filler aggregates compared with the control. The lower viscosity of compounds containing modified blacks indicates improved processability.
Oil Palm Fibre Reinforced Polymer Composites: A Review
Authors: Zuhri M.Y.M. , Sapuan S.M. , Ismail N.
Published: September 2018

In recent years there has been growing interest in utilising natural fibres as reinforcement in polymer composites for making low-cost construction materials. Hitherto, the use of natural fibres has been more traditional than technical. These fibres have long served many useful purposes, but the application of material technology for the utilisation of natural fibres as reinforcement in polymer matrices is comparatively recent. The attractive features of natural fibres include their low cost, low weight, high specific modulus, renewability, and biodegradability. Oil palm empty fruit bunches (OPEFBs) are readily available in large quantities in palm-oil mills. It has been estimated that the amount of empty fruit bunches (EFBs) available in Malaysia per year is about 4.43 million t. Oil palm fibre (OPF) can be obtained directly from the natural resource, is cheap, and also has the advantages of renewability, low cost, and easy availability. EFB fibre can be used for wood plastic, medium-density fibreboard (MDF), erosion control, and landscaping. This paper presents a literature review of the development and mechanical properties of oil palm fibre reinforced polymer composites. The mechanical properties of OPF composites are also discussed, together with their chemical, thermal, and physical properties as determined by several researchers. Both thermosetting and thermoplastic resins are used as matrices in OPF composites.
Cardanol-based Resol Phenolics – a Comparative Study
Authors: Parameswaran P.S. , Abraham B.T. , Thachil E.T.
Published: September 2018

Cardanol, a renewable agro-byproduct, can be substituted for phenol in phenol–formaldehyde resin (PF). However, resins made solely from cardanol have inferior mechanical properties. In this study, we synthesised a number of phenol–cardanol–formaldehyde (PCF), phenol–formaldehyde (PF) and cardanol–formaldehyde (CF) resins. In all these cases, the molar ratio of total phenol to formaldehyde (P:F) was maintained at 1:1.75. Subsequently, PF and CF resins were mechanically mixed in such a way as to produce phenol– formaldehyde–cardanol formaldehyde blends (PFCF) with the same total phenol to cardanol ratios as in the case of PCF resin. The mechanical, abrasive and thermal properties of the PCF and PFCF resins were studied to optimise the phenol to cardanol ratio and also for comparison of the properties of these two resins. The tensile and flexural strength decreased with incorporation of more cardanol units into the phenolic resin. However, an increase in impact strength is observed for both PCF and PFCF resins with up to 4–6 mol.% cardanol. The thermal properties of phenolic resin are negatively influenced by cardanol content. Between PCF and PFCF resin, PFCF shows better thermal stability.