Processing-Structure-Property Relationships in (TPE-E) Nanocomposites - Research Proposal Example

? Processing-Structure-Property Relationships in (TPE-E) Nanocomposites Processing-Structure-Property Relationships in (TPE-E) Nanocomposites Introduction The processing structure property relationships in (TPE-E) nanocomposites offer rich opportunities in research and development of polymer nanocomposites, with great possibilities in improving material properties. The many improvements in materials properties include electrical conductivity, toughness, optical properties, shear and bulk modulus, film scratch resistance, yield strength and many more. The addition of nanofillers such as carbon black to rubbery polymers has a great effect upon the properties of such materials and only very small amounts of nanoparticles are dispersed in the polymer matrix (Dzenis 2004). Iwahori, Ishiwata and Ishikawa (2003) argue that an understanding of the basic physical relationship in nano scale structural variables and micro scale properties of polymer nanocomposites is very important in this study. The development of polymer nanocomposites optimally using carbon nanotube and carbon nano fibre requires full comprehension of the processing structure property relationships. Aims of the Research The aim of the research is to develop improved materials properties in TPE-E nanocomposites using the processing structure property relationships. The research will develop the following objectives which will be investigated: 1. To optimally disperse the nanofillers into the TPE-E via melt processing and reactive extrusion (Nanocomposite processing). 2. To develop a complete understanding of thee processing morphology properties in the nanocomposite system, most importantly the interplay between TPE-E nanophase domains and an engineered low and high aspect ratio nanofillers (morphology and properties) 3. To comprehensively determine the mechanical and electrical performance of these nanocomposites. Literature Review According to Kotsilkova (2005) and Dobrzai (2002), an overview of the synthesis and characterization methods of nanocomposite is important in clay layer orientation and its dispersion in various nanocomposites. Many previous researches have tried to relate the clay orientation to the enhancement of materials properties from a qualitative viewpoint. Quantitative studies are may be limited because of lack of techniques to quantitatively determine the three dimensional orientation of structures in nanocomposites. In one of the recent developed techniques of determining the three dimensional orientation, the effect of compatibilizer concentration upon the orientation and dispersion of structures in polyethylene nanocomposite films was found to be thickness. An increase in concentration showed a corresponding decrease in orientation of clay layer along the thickness of the film (Bevis 1999; Suprakas, Kazuaki & Masami 2003; Liu, Hoa & Pugh 2004). Other researchers have explored ways of using commercially available products to create new materials by synthesising TPE-E to register a wide range of property improvements. The TPE-E synthesis may comprise melt compounding and reactive extrusion using organic clays as nanofillers. Hybrid composition morphology within nanocomposites, when treated in various processes, demonstrates the maximum range of properties of materials. The various methods of attaining a wide range of property enhancements are the organo clay nanofiller surface modification, additional processing parameter and the TPE-E hard and soft segment composition ratio together with the organ clay filler aspect. These material properties are governed by the manipulation of these variables and assessing the sizes of intercalate molecules (Laird & Fleming 1999; Mani et al. 2005). Colbert and Smalley (2002) argue that many other studies have focused on the microstructure processing and property relationships, which have helped in knowledge development and comprehensive understanding of these processes to develop more innovative products both for personal and commercial purposes. Hytrel products have been made in procedures that involve component fillers using thermogravimetrics. These products are associated with improved strength of plastics and flexibility in rubber, which are available in different grades such as flame retardant and stabilizers. The knowledge of nanocomposites processing in improving property grades will help products that are applied in various fields in both domestic and industrial applications. The properties enhancements could be chemical resistance and other solvents to protect industrial workers from harmful chemicals (Walters et al. 2001). Studies based on the processing property relationships compare the structure property relationships that come from two processes: the impact of ingredients and processing parameters on each process of microstructure and alignment. These microstructures properties are distribution of agglomerates, dispersion, scanning electron, confocal and transmission electron microscopy. Deagglomeration is critical in magnitude of the shear rate and the residence time. The structure property relationships are modelled based on the amount of percolation by representing the material as interpenetrating phase composite. Annealing re-establishes interconnectivity and improved electrical properties, degree of dispersion resolved by thermogravimetric analysis and extrusion speed increment inhibits thermal decomposition and asymptotically increases strength and stiffness through aspect ratio and agglomerates size reductions. Reliable models of relating macro scale mechanical properties of solid polymer nanocomposites and nano scale structural variables are very rare and unacceptable. While there is a need to create reliable predictive algorithms for industrial mechanical properties necessary for structural applications of composite materials, engineering at the nano scale is highly advantageous. Physical based bridging laws would be able to close the gap that exists between the discontinuous nano scale structure and continuum macro scale models. For ergodic systems, the macro scale experiments of averaging homogenization from cooperative relaxation domains together with their statistical weights is proportional to the total volume fraction of domains relaxing. In the case of spherical particles, the distribution of surface curvature and radial distribution of filler particles is equally very important. For anisotropic particles, more descriptive detailed indicators are required. New combinatorial approaches have been developed to determine the processing structure relationships of polymer nanocomposites, with the aim of processing high performance and multifunctional polymer nanocomposites. Significance of the Research The research hopes to stimulate the development and improvement of nano structured materials in cost effective processes to augment in the manufacture of domestic and industrial appliances. The research also hopes to address the critical issues in nanocomposites such as the great uncertainty that exists in theoretical modelling and experimental characterization of the nano scale reinforcement materials. Challenges related to nanocomposite processing are uniform dispersion of nanoparticles, alignment of nanotubes in polymeric matrix, high volume rate and high rate of fabrication in commercial manufacturing of nanocomposites and cost saving in reinforcing nanotubes. Anticipated Outcomes The tensile strength of nanocomposites will significantly increase, which will also see an improvement in impact of strength that corresponds to the same amount of nanoclay concentration with positive matrix filler interactions. Thus, expected results are reduced yields stress and the overall tensile stress. The items produced by this process will have multiple applications in human life, as some of the common products include mechanical devices for athletic footwear application, manufacturing stretch watchbands, seals, bushings and belts, pump diaphragms, impact absorbing devices, protective gears such as boots and gears, chemical and solvent resistance. New ways of processing nanocomposites are another expected outcome of the research in the manufacture of different products. The process of producing raw materials is applied in the production of other products so that there is an establishment of a wide variety of goods to satisfy human’s day to day requirements. These expected outcomes will contribute to building a knowledge base for future considerations in manufacturing of products with novelty and innovation aims and concepts. The knowledge generated will enable the use of commercially available commodities to create new raw materials by the synthesis of TPE-E to produce meaningful improvements in material properties. According to Du pont, the Hytrel thermoplastic polyester elastomer consists of a combination of desired characteristics that offer a high level of flexibility and high performance elastomers with a unique amount of resilience and hardness. The desired flexibilities are within low and high temperatures while retaining creepiness and flex fatigue. The knowledge will also contribute to nanoengineered materials that will provide low weight and numerous options to the already available conventional filled plastics. A lot of prospects of growth are anticipated in this area associated with many functionalities of the nanoscale together with the added value properties that this development is promising. With more studies dedicated to this field, nanocomposite investigations in this study will lend ideas to future researches and studies in the development of cost effective and environmentally acceptable products from the knowledge of composites. Conceptual Framework The research conceptual framework outlines the course of actions so as to provide an approach to an idea, or is an immediate theory that attempts to connect the problem definition, purpose, literature review, methodology, data collection and analysis. The research problem is to identify how processing structure property relationships in (TPE-E) nanocomposites synthesis may contribute to product and materials property improvements. This problem definition gives rise to the following research questions: Firstly, whether nanocomposite processing optimally disperses the nanofillers in TPE-E via melt processing and reactive extrusion; secondly, if morphology and properties develop a complete understanding of the processing morphology property in the nanocomposite systems; finally, if mechanical and electrical performance determines the improvement of property improvements in nanocomposites (Ericson et al. 2004). Design and Methodology Highly multilayered oriented films areas induced to a high level of shearing to the melt are to be obtained during the non-conventional moulding processes. The structure development is to be observed by the use of polarized light microscope and scanning electron microscopy. Fracture is energy to be computed from the specimens The polymer materials are polypropylene homopolymer, polycarbonate, maleic anhydride grated polypropylene and organo modified nanoclay. Thereafter, several different material compositions are studied, after which the specimens are prepared and the moulding process is set at different conditions to provide bar specimens. The morphology characterization is then observed by polarized microscope and scanning electron microscope (Vigolo et al. 2000; Li, Kinloch & Windle 2004). Surface Modifiers Nanoclays were modified by alkyl ammonium salts, with a structure having the ammonium halide connected to the organic tail group, such as ammonium chroride or ammonium bromine. The alkyl salts being obtained in a variety of lengths from 6 methyl units to over 00 methyl units. The surface modifiers used were Ethoquad 012 (Etho), choline chroride (CC), octadecyltrimethyl ammonium bromide and dimethyldiocadecylammonium chroride. The chemical structures are illustrated in Figure 1. The four modifiers were used with increasing hydrophobicity to observe the modification levels. To assist the interaction between the TPE-E nanoclay increases, the degree of intercalation and exfoliation increases, as expressed in Table 1. a) b) c) d) Figure 1. Chemical structure of surface modifiers: a) Etho b) CC c) ODTMA d) DMDOA Nanofiller Surface Modification Abbreviations Compositions 1. ME100 Emod 75% Etho and 25% CC Qmod 100% Etho Dmod 75% ODMTA and 25% CC Amod 75% DMDOA & 25% CC Table 1. Types of surface modification applied to the nanofillers The proposed Research Getting products from DuPont (Hytrel), which are commercially available, aims at generating new materials having a wide range of material properties. Therefore, a large range of TPE-E is synthesized through meltcompounding together with reactive extrusion using organoclays as the nanofiller. This allows for documentation of the process and hybrid composition morphology of the nanocomposite material subjected to different methods of treatment to see the widest range of materials properties. This is achieved by the key variables being manipulated, such as the organoclaynanofiller aspect ratio, organofiller surface modification, TPE-E hard and soft segment composition ratio and other processing pine clay that is modified arameters. The manipulation allows for the assessment of the size of intercalant molecule and other functional groups affecting the nanocomposite properties (Sandler et al. 1999; Martin et al. 2004; Che, Cagin &Goddard 2000). Timelines Research Timeline Over 30Months Activity 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Literature review                                                         Synthesis of organo-clays with: (a) Variation of modifier’s hydrophobicity                                                   (b) Variation of clay aspect ratio                                                   Characterisation of organo-modified clays by FT-IR, XPS, XRD, TGA, DLS, contact angle, SANS, TEM, SEM                                                       Preparation of TPE-E nanocomposites by melt compounding (Nanofiller with different surface modifiers)                                                     Mechanical testing on TPE-E nanocomposites (tensile strength, tear strength, tensile creep, compressive set)                                                       Thermal testing (DMTA, DSC)                                                         XRD                                                 TEM                                                 SAXS                                                   Preparation of TPE-E nanocomposites by reactive extrusion (Nanofiller with different surface modifiers)                                                     Mechanical testing                                                   Thermal testing (DMTA, DSC) XRD                                                         TEM                                                         SAXS                                                         Confirmation preparation                                                         Expansion and more details study of processing parameters of TPE-E nanocomposites                                                         Mid-candidature preparation                                                         Identifying area of application                                                         Conference Preparation                                                         Thesis write-up                                                         Bibliography Berber, S, Kwon, YK & Tomanek, D 2000. ‘Unusually high thermal conductivity of carbon nanotubes’, Phys Rev Lett, vol. 84, no. 20, pp. 4613–6. 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