As relações entre o público e o privado no processo de expansão do ensino superior no Brasil: democratização ou mercantilização?

The present study analyzes the expansion of Brazilian superior education, investigating how the public and the private sectors are inserted in this process, taking as analysis dimensions the philanthropic actions, the democratization and the mercantilism. The study had for general objective to analyze the dynamics of the expansion of superior education in Brazil, investigating how it configures the overlap between the public and the private in this process. More specifically was tried: a) to understand the process of participation of the non-state public, state and private sectors with lucrative goals in the expansion of superior education; b) to analyze the limits between the democratization and mercantilism in the process of expansion of superior education; c) to analyze the mechanisms that express the privatization in the process of expansion of superior education; d) to investigate, in a program of the government, how is materialized the overlap between the public and the private, in the expansion of superior education. In the development of the study, was adopted as theoretician and methodological way a historical and critical perspective, because is considered it allows to understand the mediations between the inquiry subject and the historical context in which it is developed, allowing, this way, the true explanation of the studied object. About the technician procedures, it was adopted documentary and bibliographical research. Also, secondary data were searched on the main governmental web sites (INEP, SISPROUNI, INEP, PNUD; IBGE) which produce statistics on superior education and sponsors of private institutions of superior education, as example ABMES and the Court of Accounts of the Union, amongst others. The study results had delineated a picture that allows to evidence that has been occurring, in the country, a process of expansion of superior education, marked for the articulated participation of the public state, private with lucrative ends and private without lucrative ends sectors, but it is distinguished in recent years the prevalence of the private sector with lucrative ends. In result, it is concluded that this process of expansion cannot be considered as dimension of the democratization because it occurs by means that move it away from the education as a right to be placed in the scope of the market, changing the right into a service that is appropriated by mercantile relations

Praxiologia e representação social sobre formação de professores nas licenciaturas da UFPI

At this investigation it was analyzed the content and the organization of the social representation on the object teachers education, built by teachers of degree courses from Universidade Federal do Piauí(Ufpi), understanding such representation articulated to the teaching habitus of these educators of teachers, what takes under consideration the position that they hold in the structure of the national field and in the subfield of teachers education. For that, it is searched: a) to emphasize the properties of the place in which the trainers act Ufpi as the office of those field and subfield; b) to understand who are the trainers, that is, to grasp the teaching habitus of the trainers with a view of its origin, social trajectory and the specifics of their position in the analyzed field and the subfield and c) to know what they think about their work object, that is, identify and articulate the content and the organization of the social representation analyzed with their properties of field and subfield agents. The research includes the specific degree courses of the Campus Ministro Petrônio Portella , from Teresina(PI), and it was applied to 134 professors of degree courses from this Campus. The data collect joined to the participants happened on the second period of 2008 and on the first semester of 2009. The starting point of the study is the corroboration that the reform of Ufpi degree courses, determined by the legislation and stablished at this Institution in 2005, altered a little the previous situation. It is comprehended that Ufpi and its structures of teachers education as a trainer institution, is limited by the national academic field and by the subfield of teachers education. From this last one, it was listed some of its properties, to show that it is about an academic subfield in construction process. It is emphasized division of the subfield, that separates the trainers into two subgroups the ones who dedicate themselves to the specific education on the contents and those ones who are specialized on pedagogical education placed in antagonistic position and competing by the symbolic power of imposing the meaning and the sense of the teachers education in the degree courses. To understand the comprehension of the problem, it is searched for the models that are in the root of the construction of the University and its project of teachers education in the degree courses, to clarify the matrixes in which the social representation searched is stablished. The theoretical referential articulates the contributions of Moscovici, the theory of social representations, and of Bourdieu, with the concepts that compose its praxeology, as habitus, social field, capital, symbolic power and others, as well as their interpreters and continuators, as Domingos Sobrinho. From the literature about the university and teachers education, it was used Dermeval Saviani, Luiz Antônio Cunha, Maria Isabel da Cunha and Mirian Jorge Warde, besides others. Plurimethodological procedures were adopted, combining associative techniques adjusted to the access to the social representations, and a classic technique, a questionnaire about teaching habitus. The condition is that the teachers build different social representation of the object teachers education because of the distinct positions that they occupy in the structure of the academic field and the subfield of the teachers education. The reached positions in the field and subfield are due to the differences in the origin and social trajectory of these agents, who, therefore, have different teaching habitus from which they build their social representation about their work object. It is highlighted that the teaching habitus and the social representation of two subfields, identified by the belongings to different dimensions of the teachers education in the degree courses, they have similarities and, also, differences. These ones permit to support that the subjects are holders of distinct teaching habitus that conceive different practices, struggles, tensions and conflicts around the sense of teachers education

Podcast na educação brasileira: natureza, potencialidades e implicações de uma tecnologia da comunicação

This thesis aims to build a panoramic analysis with the intention of providing the theoretical initial a thought articulated educational of podcast, a technology orality distributed demand. This joint search considering the various spheres that educational technology in Brazilian use, both in school and non-school contexts, including scenarios and distance. This study unites questions addressed piecemeal in the area to new perspectives about the podcast, in order to characterize its nature, examining such technology from a perspective of educational technology itself, as well as unveiling its main potentials and implications. The survey was conducted from the combined use of quantitative and qualitative categories, with emphasis on the last one. The method of participant observation was followed by immersion of the researcher in the audience groups of Brazilians podcasts. Data collection with sources held in non-school contexts, from a look at targeted interactions given the blogs of Brazilian productions, as well as from open-ended interviews with producers - made online - besides giving themselves from the hearing itself about five hundred podcasts of Brazil. In the school context, the research focused on a literature review of the literature of the study area. Were added to the corpus described statistics derived mainly from "Podpesquisa 2009," Numerical major survey on the use of podcasts in Brazil. The articulation and analysis of the collected data, we used the concept of Education Paulo Freire (1971, 1987), so that, understanding it as synonymous to communication - understood this concept in Freire - were able to reveal the various ramifications educational podcast Brazilian atmosphere permeated by a dialogic between its participants. Moreover, the ideas of Célestin Freinet (1998) about the cooperation, while education practice, conducted the analyzes productive technology addressed in this work. The philosophical thought of Andrew Feenberg (2003) on the notion of "technologies" buoyed technological design elaborate. Such consideration provided the foundation for the reflections and proposals offered in this study, which, in the characterization of the oral nature of the podcast - especially their version for the deaf - appropriated the placements Luis Antonio Marcuschi (2001) about the relationship between orality and writing. In addition to these references, several other authors were considered, dealing with issues that pervade the theme here delimited, contemplating discussions on topics such as educational interest, online production, inclusive education, among other aspects. At the end, there was the podcast as a technology, while still reproducing social asymmetries Brazilian fairly directed at promoting mitigations hierarchical and open production in digital orality promotes. In view of its technical and educational implications in national use, the technology study has revealed potential relevant to the sophistication of teaching practices with orality, in various contexts, and proved adequate to serve as a motto to the revision of school practices, to even the very role of the school. This, by the prospects unveiled here, can, through the podcast, mitigate their questions reproductivist to constitute themselves as under privileged communication, boosted by critical rescue and sophistication of management through the most basic education component: speech

Os jogos com regras na perspectiva do desenho universal: contribuições à educação matemática inclusiva

To think about a school that is for everyone has been a challenge for many people connected to education worldwide demanding from researchers of each level of knowledge an association to such effort. The study presented on this paper unites itself to the voices, movements and researches of these scholars, seeking to contribute on building possibilities on which mathematics can be thought and worked on schools in order for every student to learn, whether they have some sort of deficiency, disorders, syndromes or not. This essay has the goal to investigate the possibilities of inclusive pedagogical practices mediated by math games with rules, developed and used throughout the Universal Design perspective; a qualitative research took place with a collaborative methodology that involved managers, teachers and students from a public school situated on the city of Natal/Brazil. On the investigation math games with rules were developed and made according to the Universal Design concept, starting from initial studies which articulated theoretical groundings to the reality of school and the teacher s conceptions. After that, classes using these tools were planned collectively which oriented inclusive pedagogical practices of classes from the 1st to the 4th year of elementary school. Throughout the process many instruments such as: tape recording, video footages, notes from the researcher; the teachers and the students were used for constant work evaluation and also to record the research data. In the end, the data indicated effective contributions of the mediated pedagogical practices by games with rules under the perspective of Universal Design for Inclusive Mathematics Education

Os currículos praticados no cotidiano da EJA: regulações e emancipações na Escola Centro Educacional Dr. Pedro Amorim

This research has as its object of study practiced in the daily curriculum of Youth and Adults in their midst and considered discussion of the concepts of knowledge as regulation and emancipation. The camp of our research relates to the knowing / doing the teachers of this modality of education, in the Escola Centro Educacional Dr. Amorim-CEPA, the city of Assú/RN and is articulated to the emerging desire to understand how cooperating teachers have thought, organized and practiced the curriculum in order to consider the many complex situations that are present in everyday school life. Our tour was guided by the need to study the relationship between the regulated curriculum and practiced in everyday adult education, as well as to understand, from the knowing / doing of the teachers, the conceptions that guide their teaching practices and, therefore, reflect on this Reality curriculum in order to better signify then. In this sense, we turn to the fundamentals of qualitative research, adopting the procedures of documentary research, participant observation and semi-structured interview, which allowed us to enter a universe of complex dimensions, senses, and that add significant difference, because the forms of use of various practitioners are and unique, in that enroll in school life and define their brand identities. The predominance of a traditional teaching practice nature by a process of training and teaching experience, the lines of flight, volatilities and inventiveness promoted by the circumstances of everyday life are some of the conclusions we draw from the data collected. This reality, we infer that the practice of teachers varies between regulation and emancipation, being this time, many challenges to be faced, namely the process of continuing education, the conceptual understanding of the subject curriculum and the existence of relational different knowing / doing produced, used and created in/from the school routine of Youth and Adults

Apoio pedagógico, ação coletiva e diálogo: tramas da formação continuada em educação inclusiva

This work detaches the importance of the continued formation of the educators in terms of the inclusive educational process, pointing as basic elements the continued formation of the educational professionals. In this direction, it points and it defends the dialogue in the perspective of David Bohm, with interfaces of the freireanas ideas, as a methodological resource of action that allows the organization of strategies of collective and effective pedagogical support in inclusive schools, in the same time articulates the continued formation of the professionals in education. Characterized as research in a dialogical action with collective participation and collaboration, it counted with the participation of 87 educators, between professors, pedagogical, managing coordinators and specialists of special education in two schools of the state and municipal public system of Natal/RN. The results had pointed with respect to the viability of the dialogue as articulated methodological tool of the continued formation in service, when providing the establishment of personal and professional relationship between the educators, favoring the discursive enjoyment of the lived experiences, allows the organization of strategies of collective and effective pedagogical support in the scholar environment. On the basis of these results, this work also points to some items to reflections as the reorganization of the Secretariats and the schools, in the direction to brighten up the fragmentation and the discontinuity of the pedagogical actions evidenced and to instigate a process of changes that has glimpsed the professional development of the educators through its continued formation in service and the improvement of the school in the way of the concretization of an education directed toward the acceptance, respect and attendance the diversity of its pupils, as detaches the official documents and the studies on the inclusive education

Narrativas de formação de professoras dos anos iniciais do ensino fundamental: Concepções e construções de necessidades formativas na Geografia Escolar

This article is about a study about the training needs for teachers of elementary school in the field of Geography. It is our objective to grasp their conceptions of training needs and reflect about their formative needs to teach geography. We consider the training as reflective process that involves the movement of changes and improvement beyond of formal learning, considering its numerous dimensions. We reflected about formative needs in light of the readings of Rodrigues Esteves (1993), Silva (2000), Roberts (2006), Vieira (2010). The discussions about conceptions were based on Ferreira (2007). The empirical reference constitutes to a private school in the city of Ceará-Mirim/RN, SECAT Centro de Ensino. The social subjects of our research are five teachers who work in the initial years of elementary school. We resorted a survey (auto) biographical, based on the studies of Passeggi (2011), Delory (2008), Bertaux (2010) e Josso (2010), since it is our intention to turn to the historicity of the subject and the learning, recognizing the links between him and the world and the experiences based on for learning and adult training. As technical and methodological procedure we will use the Training Narratives, whose application allows the understanding of memories and stories of schooling teachers, since are reported events occurred during the development of the individual through seminars Biographical. We observed on the narratives constructed by the teachers the absence assignments of meanings to a reworking of the theoretical formative needs and questions of its organizing principles. However, we notice the teachers were able to develop senses and means to conceive the phenomenon in study, in a descriptive way, through articulated enunciations, including aspects and opportunities linked to their teaching practices and future formative prospects. Regarding School Geography, we based our studies in the reflections of Smith Junior (1994, 2000), Tonini (2003), Vesentini (2004) and Vlach (1991), among others. We verified that the needs evidenced by the teachers to teach geography were constructed from the contexts of their teaching practices present in their school and professional trajectories. Therefore, we noticed the need for formal pedagogical qualification so that we can conceive the phenomenon in study beyond its descriptive character, understanding that it is necessary to point out reflections and questions about the dynamics of production of global capital, which conveys its interests in the contexts that often emerge formative needs of the educational system.

A coordenação pedagógica e o processo de inclusão do aluno com necessidade educacionais especiais:Um estudo de caso

The school inclusion presents a number of challenges that has been mobilizing initiatives and studies about its effectiveness. If on one hand in such studies and initiatives it becomes important to emphasize on the role and training of teachers, on the other, there is few studies about the role (and performance) of the pedagogical coordination in face of this process. In this sense, this research focuses on the role of educational coordination in face of the school inclusion of students with Special Educational Needs (SEN) and it undertakes the following study s questions: has the action by the coordinator contributed to the process of including students with Special Educational Needs? How is it presented in the process of inclusion of students with SEN in regular education? And it aims to: investigate the role of the pedagogical coordinator in the process of inclusion of students with Special Educational Needs of Primary Education at regular schools; and to analyze the limits and possibilities of the coordinator actions in the process of inclusion of students with SEN. For the effectiveness of the research, a state school of Elementary School located at the city of Natal/RN was taken as an empiric field. It was selected as research subjects 4 coordinators, 2 teachers of the Multifunctional Resources Room and 2 teachers of 6th to 9th grades. The methodological approach that was used in this research is consistent with the qualitative approach, and it is configured as a case study, as it is understood that this type of research responds to the objective of the study, assuming the observation of everyday school life, the educational document analysis and interviews with the subjects as procedures and tools to build data. The construction and analysis of the data were followed by a dialogue with the literature dedicated to coordinating education and school enrollment. Considering the responsibilities of the contemporary pedagogical coordination due to the challenges and possibilities of schooling for all students, specially regarding to what is referred as collaborative work and ongoing training of teachers, this study points out to the lack of an articulated action related to the school inclusion process, considering the monitoring of the teaching activity and its dialogue with the Multifunctional Resources Room. Moreover, the emphasis on meeting the daily school routines and the compliance with bureaucratic procedures, put it into second, restructuring of the Political-Pedagogical and the possibility of mobilization of school around the problematization and systematization of an inclusive school project. The effectiveness of school s inclusion, therefore, implies the scaling of the functions of the pedagogical coordination, as well as the reorganization of the school it self, to ensure the mediation of collaborative actions, contemplating the teachers continuing education, having as a landmark difficulties, problems and experiences constructed in the school context

PROEJA FIC/Fundamental no IFRN-Campus Mossoró: das intenções declaradas ao funcionamento de um curso em espaço prisional

This research aims to analyze the FIC Course of Assistant Technician in Service Management and Quality, integrated to elementary education / EJA form developed by IFRN MO Campus between 2011 and 2013 in the form of a PROEJA FIC / AT ELEMENTARY SCHOOL LEVEL. We seek to understand the adhesion between the national guidelines postulated for the Program, established in PPC and mediations with the process conceived in the run of the course. Guiding by the socio-critical approach and the dialogical paradigm, the theoretical-epistemological mark is especially buoyed by the theoretical contributions of Ciavatta (2005) , Rock (2011) , Haddad and Di Pierro (2000), Freire (2005), Marx (1982), Ramos (2005), Frigotto; Ciavatta; Ramos (2005), Moura (2012), and also on education in prisons by Onofre (2007, 2011), Bueno (2007), Julião (2011) and Foucault (2001). We assume that an action that enables professional qualification as FIC courses articulated to the EJA in the context of education in prisons have conceptual, methodological, political and pedagogical implications for it focuses challenges, weaknesses and opportunities on the same area of education., We have developed four techniques of data collection based on procedures and tools of qualitative research, such as document analysis, a student survey, the conduction of focus groups with teachers and administrators of the course and on-site observation. Mediated by the investigated context, results showed that the consolidation of PROEJA FIC / AT ELEMENTARY SCHOOL LEVEL goes beyond the intentions officially declared. It is inferred that after seven years of its creation, even though it keeps some potential, this program is not being satisfactorily developed and it shows weaknesses national and locally, it is set at low capillarity, it has a limited scope, and dissolved essential public commitments to the course development. The effectiveness of PROEJA FIC / AT ELEMENTARY SCHOOL LEVEL as part of an emancipatory inclusion social policy, according to official statement, entails approximating the legal logic with social logic, so as not only to propagate discourses and enforce worship to specific and successful experiences that reach only a minority, but to provide actual and necessary conditions to promote the breadth and social quality of the offered deals in this program format

Ações dos agentes comunitários de saúde diante do usuário da estratégia saúde da família com estados depressivos no Município de Abaiara-CE-BR

Brazilian health public assistance is going through two Reforms, Sanitary and Psychiatric, and through these the assistance is guaranteed in the three levels: primary, secondary and tertiary. Thus, mental health assistance should be offered since preventive cares until the ones that demand larger technological apparatus. Programs like Health Community Agent's Program (HCAP) and Family Health Strategy (FHS), besides increasing the services coverage, have been making possible the system reorientation in the meaning of integrality, universalization and equity. Thus, united intervention of mental health team and FHS can offer several benefits to the population, providing assistance and follow-up to patients with mental disorder. It was aimed to assess health community agents facing the user of Family Health Strategy in depressive state. This quanti-qualitative study took place in the municipal district of Abaiara-CE. Semi-structured interview was applied with health community agents and Beck Depression Inventory with the users registered in Family Health Strategy. It was verified that among the 64 users interviewed, 12.5% didn't present symptoms of depression, 10.9% presented symptoms of light depression, 14.1% symptoms of moderate depression and 62.5% symptoms of serious depression. For the 22 health community agents interviewed, they all reported the existence of people with symptoms of depression in their personal micro-areas, being difficult to work with them, once the FHS team is not qualified to work with mental health problems. It was verified that the Municipal district doesn't have specialized professionals, making difficult the routing and treatment. Based on these results, it was concluded that in spite of the articulation of mental health with FHS is necessary and benefactor to the population, it still doesn't exist, worsening the situation, mainly in small Municipal districts, once they don't have mental health services. Thus, the population is exposed and without follow-up, which allows the identification of installed diseases and with gravity, like depression, because there are no prevention and control activities. It is recommended, due the extreme need, the elaboration and implantation of a mental health program in these municipal districts, articulated with FHS

Trajetória do hospital dia Dr. Elger nunes: um recorte histórico da psiquiatria e saúde mental no Rio Grande do Norte

In Brazil, the mental health network proposed by the Psychiatric Reform inserts the intermediate and replacement services in the pursuit of alignment or resocialization of patients with mental and behavioral disorder in the community. Was adopted, among other services, the Center for Psychosocial Care, Home Therapy, Sheltered Home, Day Hospital and psychiatric beds in general hospital. In this context, the State of Rio Grande do Norte implanted the Day Hospital Dr. Elger Nunes (HDEN) in Natal / RN in 1996, linked to State Department of Public Health. At HDEN happened a multi and interdisciplinary therapeutic work, besides being the scene of disciplinary practices, and extension projects for graduate courses in Higher Education Institutions in the city. However, with the process of decentralization of local services, the hospital was terminated by an administrative state act in 2006, leaving damage to the activities provided to users, disciplinary practices and extension activities. From this breakdown, the objective was to narrate the trajectory of HDEN through a multidisciplinary team of professionals and teachers who used it as a field of disciplinary practices. It is characterized as a documental and qualitative, backed in the technique of thematic oral history, following the phases: authorization of the interviewee, interview recording, transcription, textualization and transcreation of the material obtained. We used documents, ordinances, general reports of activities, among others, plus interviews to fifteen employees who used this service, being thirteen part of the multidisciplinary team of professionals and two graduation professors of health care area, nursing and medicine. The stories collected were organized according to the technique chosen, respecting its steps. In preparing the body subjected to ALCESTE computer program, priority was given to the vital tone for the formation of categories and classes elected by the program, structured in three thematic areas. In the first axis, called Trajectory of HDEN, were recalled the beginning of its activities, the steps of that time, their activities, and its actors - users, families, professionals, and teaching practices. The second axis has dealt with the process of extinction of HDEN, rescuing the feelings of employees, the main reasons given at the time and immediate postextinction scenario. And the third axis revealed in an articulated form the situation of mental health in Natal / RN, listing to the challenges and prospects for the psychosocial care, starting from the trajectory of HDEN with emphasis on activities. Moreover, the trajectory of HDEN provides recognition of the historical basis outlined in the constitution of the network of substitute services present in the current scenario of psychosocial care in the city of Natal and in RN.

Viabilidades térmica, econômica e de materiais de um sistema solar de aquecimento de água a baixo custo para fins residenciais

An solar alternative system for water heating is presented. Is composed for one low cost alternative collector and alternative thermal reservoir for hot water storing. The collector of the system has box confectioned in composite material and use absorption coils formed for PVC tubes. The box of hot water storage was confectioned from a plastic polyethylene drum used for storage of water and garbage, coated for a cylinder confectioned in fiber glass. The principle of functioning of the system is the same of the conventionally. Its regimen of work is the thermosiphon for a volume of 250 liters water. The main characteristic of the system in considered study is its low cost, allowing a bigger socialization of the use of solar energy. It will be demonstrated the viabilities thermal, economic and of materials of the system of considered heating, and its competitiveness in relation to the available collectors commercially. Relative aspects will be boarded also the susceptibility the thermal degradation and for UV for the PVC tubes. It will be shown that such system of alternative heating, that has as main characteristic its low cost, presents viabilities thermal, economic and of materials

Projeto, construção e levantamento de desempenho de um concentrador solar cilíndro parabólico com mecanismo automático de rastreamento solar

An cylinder-parabolic solar concentrator is presented to produce steam for different applications. This prototype was built in glass fiber with dimensions that follow a study of optimization of parameters inherent in the optical reflection of sunlight by the surface of reflection and absorption of the same by tubing that leads the fluid of work. The surface of the concentrator of 2.24 m² has been covered by layers of mirror with 1.0 m of lenght and 2.0 cm wide. The absorb tubing consists of a copper tube diameter equal to 28 mm. The concentrator is moving to follow the apparent motion of the sun. It will be presented the processes of manufacturing and assembly of the concentrator proposed, which has as main characteristics the facilities construction and assembly, in addition to reduced cost. Will be presented data from tests performed to produce steam setting up some parameters that diagnose the efficiency of the concentrator. It will be demonstrated the viabilities thermal, economic and of materials of the proposed system.The maximum temperature achieved in the vacuum tube absorber was 232.1°C and average temperature for 1 hour interval was 171.5°C, obtained in a test with automation. The maximum temperature achieved in the output of water was 197.7°C for a temperature of 200.0°C in the absorber tube. The best average result of the water exit temperature to interval of 1 hour was 170.2°C for a temperature of 171.2°C, in the absorber tube, obtained in test with automation. Water exit mean temperatures were always above of the water steaming temperature. The concentrator present a useful efficiency of 38% and a production cost of approximately R$ 450,00 ( $ 160.34)

Projeto, construção e análise de desempenho de coletores solares alternativos utilizando garrafas pet

A solar alternative system for water heating is presented. It work on a thermosiphon, consisting of one or two alternative collectors and a water storage tank also alternative, whose main purpose is to socialize the use of energy mainly to be used by people of low income. The collectors were built from the use of pets bottles, cans of beer and soft drinks and tubes of PVC, ½ " and the thermal reservoirs from a drum of polyethylene used for storage of water and garbage placed inside cylinder of fiber glass and EPS ground between the two surfaces. Such collectors are formed by three elements: pet bottles, cans and tubes absorbers. The heating units, which form the collector contains inside the cans that can be closed, in original form or in the form of plate. The collectors have an absorber grid formed by eight absorbers PVC tube, connected through connections at T of the same material and diameter. It will be presented data of the thermal parameters which demonstrate the efficiency of the heating system proposed. Relative aspects will be boarded also the susceptibility the thermal degradation and for UV for the PVC tubes. It will be demonstrated that this alternative heating system, which has as its main feature low cost, presents thermal, economic and materials viabilities

Avaliação tribológica dos polímeros NBR, PTFE e PTFE gravitado em contato com aço AISI 52100

Low cost seals are made of NBR, Nitrile Butadiene Rubber, a family of unsaturated copolymers that is higher resistant to oils the more content of nitrile have in its composition, although lower its flexibility. In Petroleum Engineering, NBR seal wear can cause fluid leakage and environmental damages, promoting an increasing demand for academic knowledge about polymeric materials candidate to seals submitted to sliding contacts to metal surfaces. This investigation aimed to evaluate tribological responses of a commercial NBR, hardness 73 ± 5 Sh A, polytetrafluoroethylene (PTFE), hardness 60 ± 4 HRE and PTFE with graphite, 68 ± 6 HRE. The testings were performed on a sliding tribometer conceived to explore the tribological performance of stationary polymer plane coupons submitted to rotational cylinder contact surface of steel AISI 52100, 20 ± 1 HRC Hardness, under dry and lubricated (oil SAE 15W40) conditions. After screening testings, the normal load, relative velocity and sliding distance were 3.15 N, 0.8 m/s and 3.2 km, respectively. The temperatures were collected over distances of 3.0±0.5 mm and 750±50 mm far from the contact to evaluate the heating in this referential zone due to contact sliding friction by two thermocouples K type. The polymers were characterized through Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). The wear mechanisms of the polymer surfaces were analyzed by Scanning Electron Microscopy (SEM) and EDS (Energy-Dispersive X-ray Spectroscopy). NBR referred to the higher values of heating, suggesting higher sliding friction. PTFE and PTFE with graphite showed lower heating, attributed to the delamination mechanism