Studies on Elastomer Blends with special reference to NBR/Butyl, NR/Butyl and NBR/EPDM Blends

The distribution of curing agents and fillers in the constituents of an elastomer blend is an important factor which determines the curing behaviour and vulcanizate properties of the blend. The distribution of curatives and fillers largely depends on the nature of elastomers. The curatives tend to migrate preferentially to the rubber of higher unsaturation and/or higher polarity, and reinforcing fillers tend to get distributed in the low viscosity phase, resulting in inferior mechanical properties of the blends. The thesis suggests several methods for improving mechanical properties of blends like NBR/butyl, NR/butyl, NBR/EPDM and NR/.

Studies On Thermoplastic Elastomers With Special Reference To Triblock Copolymers And Nbr/Pvc Blends

Thermoplastic elastomers are a relatively new class of materials which compete with thermoset rubbers in some areas and thermoplastic materials in other areas. The main thrust of the present investigation is a comparative study’ on commercially .available triblock. styrene thermoplastic elastomers and those derived from blends of acrylonitrile-butadiene rubber and poly(vinyl chloride). The styrene—based thermoplastic elastomers are gaining acceptance as a replacement for both natural and synthetic rubber‘ in many‘ applications. TPEs based on blends of elastomers and plastics ix: the fastest growing segment of the broad class of thermoplastic elastomers. Broad applicability and simple technology of production are the attractive features of this class of TPES. NBR/PVC thermoplastic elastomers were selected for this investigation due to the versatility of PVC, its number one position, low cost. ability to Ina compounded into various flexible and rigid form with good physical and chemical and weathering properties etc., which will be passed over to PVC blends especially NBR/PVC blends which are known to form miscible systems

New accelerator system for low temperature curing of elastomers with special reference to NR, NBR and NR/BR blends

The primary objective of this work is to develop an efficient accelerator system for low temperature vulcanization of rubbers. Although xanthates are known to act as accelerators for low temperature vulcanization, a systematic study on the mechanism of vulcanization, the mechanical properties of the vulcanizates at varying temperatures of vulcanization, cure characteristics etc are not reported. Further. xanthate based curing systems are not commonly used because of their chance for premature vulcanization during processing. The proposed study is to develop a novel accelerator system for the low temperature vulcanization of rubbers having enough processing safely. lt is also proposed to develop a method for the prevulcanisation of natural rubber latex at room temperature. As already mentioned the manufacture of rubber products at low temperature will improve its quality and appearance. Also, energy consumption can be reduced by low temperature vulcanization. in addition, low temperature vulcanization will be extremely useful in the area of repair of defective products, since subjecting finished products to high temperatures during the process of repair will adversely affect the quality of the product. Further. room temperature curing accelerator systems will find extensive applications in surface coating industries.

Studies on the use of Nanokaolin, MWCNT and Graphene in NBR and SBR

The current research investigates the possibility of using unmodified and modified nanokaolin, multiwalled carbon nanotube (MWCNT) and graphene as fillers to impart enhancement in mechanical, thermal, and electrical properties to the elastomers. Taking advantage of latex blending method, nanoclay, MWCNT and graphene dispersions, prepared by ultra sound sonication are dispersed in polymer latices. The improvement in material properties indicated better interaction between filler and the polymer.MWCNT and graphene imparted electrical conductivity with simultaneous improvement in mechanical properties. Layered silicates prepared by microwave method also significantly improve the mechanical properties of the nanocomposites. The thesis entitled ‘Studies on the use of Nanokaolin, MWCNT and Graphene in NBR and SBR’ consists of ten chapters. The first chapter is a concise introduction of nanocomposites, nanofillers, elastomeric matrices and applications of polymer nanocomposites. The state-of-art research in elastomer based nanocomposites is also presented. At the end of this chapter the main objectives of the work are mentioned. Chapter 2 outlines the specifications of various materials used, details of experimental techniques employed for preparing and characterizing nanocomposites. Chapter3 includes characterization of the nanofillers, optimsation of cure time of latex based composites and the methods used for the preparation of latex based and dry rubber based nanocomposites. Chapter4 presents the reinforcing effect of the nanofillers in XNBR latex and the characterization of the nanocomposites. Chapter5 comprises the effect of nanofillers on the properties of SBR latex and their characterization Chapter 6 deals with the study of cure characteristics, mechanical and thermal properties and the characterization of NBR based nanocomposites. Chapter7 is the microwave studies of MWCNT and graphene filled elastomeric nanocomposites. Chapter 8 gives details of the preparation of layered silicates, their characterization and use in different elastomeric matrices. Chapter 9 is the study of mechanical properties of nanoclay incorporated nitrile gloves .Chapter 10 presents the summary and conclusions of the investigation.

Credenciamento de laboratórios de ensaios de construção civil segundo a NBR ISO/IEC 17025 : avaliação das dificuldades e nao-conformidades envolvidas no processo

A globalização, a busca pela qualidade e produtividade, a competitividade do mercado, fizeram com que a Construção civil iniciasse a busca pela melhoria nos processos, visando diminuir o desperdício e as perdas. Por outro lado, as empresas construtoras têm buscado a certificação dos seus sistemas de qualidade, o mesmo ocorrendo, ainda que de forma incipiente, com os fornecedores da indústria da construção civil. Considerando a cadeia produtiva deste setor, os laboratórios de ensaios aparecem ensaiando os produtos que buscam a certificação, realizando controle tecnológico nas obras, caracterizando os materiais utilizados, entre outros, mostrando assim a sua importância tanto para os fornecedores quanto para os construtores. Para garantir melhorias no setor da construção civil, não é importante apenas a implantação de sistemas da qualidade nas empresas construtoras, mas também é de grande relevância a certificação de produtos utilizados. Para tanto, é necessário a existência de laboratórios credenciados que desempenhem o papel de ensaiar o produto. A necessidade da existência de laboratórios credenciados é visível no país, para garantir aspectos referentes à confiabilidade e confidencialidade dos resultados, além da rastreabilidade dos padrões utilizados. Também é importante que a execução dos ensaios seja feita por pessoal treinado e qualificado, com utilização de procedimentos permanentemente revisados e atualizados. O objetivo deste trabalho é levantar as principais dificuldades e não-conformidades vivenciadas pelos laboratórios de ensaios de construção civil para alcançar o credenciamento, identificando-as através de questionários. Este diagnóstico pretende apontar diretrizes que viabilizem o processo de credenciamento de laboratórios de ensaios de construção civil de forma a facilitar a disseminação desta prática em todo o país.

Manual de operação, uso e manutenção das edificações residenciais : coleta de exemplares e a avaliação de seu conteúdo frente às diretrizes da NBR 14.037/1998 e segundo a perspectiva dos usuários

O Manual de Operação, Uso e Manutenção das Edificações ou, simplificadamente, Manual das Edificações, constitui uma garantia legal para os usuários das edificações. A entrega deste documento pelas empresas e consultas pelos usuários ao Manual contribuem para a redução dos custos da fase de uso da Edificação. Informá-los sobre operação, uso e manutenção através de Manuais confiáveis do ponto de vista técnico, bem como acessíveis e amigáveis para sua compreensão, se faz necessário. A publicação da NBR 14.037/1998, o Código de Defesa do Consumidor e a implantação de Sistema de Gestão da Qualidade têm sido um estímulo às empresas de construção para a elaboração desses Manuais. Neste contexto, o presente trabalho tem como objetivo contribuir para melhoria do fluxo de informação no processo produtivo da construção civil, identificando lacunas a serem supridas na elaboração dos Manuais das Edificações à luz das diretrizes estabelecidas nesta NBR. Para cumprir com o objetivo proposto, inicialmente foi realizada pesquisa exploratória com empresas do subsetor de edificações dos Estado de Alagoas e Rio Grande do Sul através de questionário. Cada questionário foi acompanhado por solicitação de remessa de Manuais das Edificações que a empresa havia desenvolvido para uma avaliação de seu conteúdo, que foi realizada através de lista de verificação. Na segunda fase da pesquisa, também utilizando questionários, foram solicitadas informações sobre experiências e expectativas dos usuários das edificações destes dois Estados sobre esses Manuais das Edificações A existência de dificuldades para elaboração dos Manuais foi evidenciada pelo baixo conhecimento pelos profissionais dos aspectos relacionados a estes documentos, pela avaliação obtida do conteúdo dos mesmos e pelo interesse das empresas em um texto básico que lhe facilite a sua elaboração. Por outro lado, percebe-se que os usuários não têm a cultura de ler os Manuais, acionando as empresas para prestar assistência técnica, mesmo que a solução da solicitação encontra-se, em sua maioria, descritas nos Manuais. De forma geral, pode-se concluir que ainda há muito a ser trabalhado com empresas e usuários para que as informações sejam adequadamente disponibilizadas e utilizadas.

Estilo Gerencial no IRD/CNEN: Possibilidades de Contribuição para a Implantação e Implementação do NBR ISO 9000

This study investigates in the National Commission of Nuclear Energy the Institute of Radiation Protection and Dosimetry in terms of perceptions, actions, and posture of the administrative agents which could facilitate the engagement of the employees of that public organization in the TQM implantation, based on NBR ISO 9000. The central question of this research is: which characteristics of the administrative actions and sense of the managerial posture manifested in the implantation, implementation and maintenance for the achievement of objectives and goals of the Quality System-ISO 9000, could contribute to engage the IRD professionals in the process? The research finds prevalence of the Quality technical knowledge over the attention on professionals' managerial posture, identifies a lack in that Norm about how to deal with its administrative requirements in practical terms, driving the researcher to look for support especially in Deming to face the critical reading of that organizational context. The field research was conceived under the paradigm of constructivism, facilitating the description of beliefs, perceptions, feelings and values manifested in the employees discourses, actions and re-actions to establish relations between Quality theory and that concrete reality. A phenomenologic approach, only as a complementary level, was sufficient to favor the researcher insertion in that institution where he is still working, but in the new and contingent role of researcher. To apprehend the organization managerial stile, to comprehend beyond its characteristics and to grasp the orientation of the managerial posture in terms of possibilities for Quality implementation were the core of this study. The TQM theory was interpreted as a living philosophy, an administrative posture the meaning of which is a permanent Quality improvement in the CNEN/IRD management processes in its internal and external organizational relations. The procedural nature of the CNEN/IRD public service legal regime, political implications and performance evaluation which reveals only partially the organizational reality should not obstruct the Institute drive to assume the spirit of serving the public as a Quality management philosophic commitment. Conclusions show some progress reorienting initiatives in organizational management taking place in three different levels: operational, toward the employees' expectations of values and organizational processes integration; HR administration, in search of better communication; strategic, through expectations on a possible visionary leadership". Finally, at the academic level, the perception that future studies in search of the establishment of relationships between TQM and the organization culture can favor new progress."

Estudo da hidrogenação catalítica de NBR

Neste trabalho temos o Estudo da Hidrogenação Catalítica de NBR em meio Homogêneo, empregando complexos dos metais de transição. Nos experimentos de hidrogenação foram testados os complexos de paládio e rutênio em duas etapas diferentes. Para estes complexos, foram estudados os efeitos de temperatura, pressão, tempo e concentração de catalisador. Ainda, investigou-se os efeitos do teor de sólido de NBR em solução. Os solventes utilizados foram acetona e metiletilcetona. A Hidrogenação do Butadieno-Acrilonitrila (NBR) foi realizado em escala laboratorial num reator Parr de 1 L. No sistema utilizando o complexo de Paládio, as duplas ligações foram totalmente convertidas nas condições de 60 °C, 27 atm, 2 g de NBR, 58 mg de catalisador e 1 h de reação. Nas reações com o complexo de Rutênio, a conversão total ocorreu nas condições de 140 °C, 40 atm, 10 g de NBR, 60 mg de catalisador e 8 h de reação. As Hidrogenações de NBR mostraram-se efetiva para ambos os catalisadores atingindo a máxima conversão (100% em mol) nos dois sistemas. No entanto, o sistema utilizando catalisador de rutênio mostrou-se mais efetivo e viável para a produção de HNBR em escala industrial.

Proposta de um modelo de gestão da qualidade para micro e pequenas empresas integrando a estratégia seis sigma à NBR ISO 9001

This work has as its main purpose to set a model of Quality Management for micro and small companies integrating the management models: Six Sigma strategy to NBR ISO 9001:2000. An exploratory research is developed to collect technical and bibliographical information on both methods, emphasizing their integration. Then, a survey is carried out on 65 analysts/consultants of Quality Management Systems and it has detected, besides other factors, that current methodologies must be associated in order to reach better results. At last, it proposes the Sigma 9001 model, which aims to make it possible for micro and small companies to objectively and with low costs, implement a Quality Management System, able to assure competitive advantage through improvement identification in the processes, as well as an improvement in the companies management

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

Avaliação de tubos de concreto reforçados com fibras de aço segundo a NBR 8890

Pós-graduação em Engenharia Civil - FEIS

Sobre a implantação de boas práticas de distribuição de produtos médicos de acordo com a RDC nº 59 de 27 de junho de 2000 - ANVISA e NBR ISO 9001:2000

Pós-graduação em Ciências Farmacêuticas - FCFAR

Levantamento para a implantação de um sistema de gestão da qualidade segundo a norma NBR ISO/IEC 17025:2005 no Laboratório de celulose e papel da UNESP-Itapeva

The aim of this study is to perform a situational analysis of the Laboratory of pulp and paper-UNESP ITAPEVA for conducting proposal the accreditation according to ISO / IEC 17025:2005. The ISO / IEC 17025 establishes the criteria for those laboratories wishing to demonstrate their technical competence, which have an effective quality system and are able to generate technically valid results, establishing a single international standard for certifying the competence of laboratories to carry tests and / or calibrations, including sampling. The case study was conducted on laboratory Pulp and Paper Universidade Estadual Paulista (UNESP), campus Itapeva, where we compared the views of the technician responsible for the laboratory and a regular user. The generated conclusion is that the laboratory is unable to initiate an accreditation process, because it fails the requirements such as quality manual, register of subcontractors, research of customer satisfaction, schedule of internal audits, schedule for completion of critical analysis, profile of the functions required, functions current description, documentation of technical requirements for accommodation and environmental conditions, calibration programs, equipment calibration program, programs calibration standards and reports and / or certificate of test and / or calibration, that are in accordance with ISO / IEC 17025:2005, beyond that there is not the possibility to develop and implement a quality system without the commitment of everyone involved, regardless of the functional hierarchy