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This research aims to characterize the tribological behavior of polybutylene terephthalate (PBT) and PBT composites with micro glass beads (MGB) on steel, in dry conditions and on a block-on-ring tester, pointing out the influence of sliding distance and speed. The tribology of PBT and its composites is still in an early stage because this thermoplastic polyester requires accurate technological and thermal treatment.

The composites were produced by ICEFS Savinesti Romania and contain PBT grade Crastin6130NC010 (as supplied by Du Pont), 0.5 […] 1.0 per cent (weight) Relamyd B-2Nf (polyamide grade produced by ICEFS, for a better dispersion of MGB), 1 per cent (weight) black carbon for technological and tribological reasons and different micro glass beads (MGB) concentrations (10.0 and 20.0 per cent weight). Tests were done for different sliding distances (2,500, 5,000 and 7,500 m) and speeds (0.5, 1.0 and 1.5 m/s) and a normal load of 5 N.

The friction coefficient and the wear parameter (as mass loss of polymeric blocks) pointed out a good tribological behavior for these composites. Scanning electron microscope (SEM) images revealed particular aspects of PBT local transfer on steel. Also, 10 per cent MGB in PBT reduces wear, especially for longer distances (75,000 m) and higher speeds (0.5 and 0.75 m/s); the friction coefficient is only slightly increased up to 0.23, being less influenced by the speed and the sliding distance as compared to neat polymer.

PBT and PBT composites could become challengers for replacing materials in applications similar to tested ones. Even the neat polymer exhibits a good tribological behavior. The composites have a lower sensibility to higher speeds and sliding distances for the applied load.

In this article the electric properties of conducting polymeric compounds with graphite filler was studied to obtain the information of its structural distinctions. It was defined, that the temperature dependences of the electrical resistivity of the investigated composite materials, which had different content of conductive filler, had the posistor properties. Their frequency dependences of dielectric permittivity were found dispersed at low‐frequency area. This phenomenon was explained based on the availability of “built‐in” charges at the boundary region to the particles of graphite of polymeric layer. It was determined by outflow of free charge carries from graphite to localized states in the polymeric matrix. The estimated thickness of “built‐in” charge, in the context of the model of concentric system of conductive particles in dielectric matrix is about a micron.

Materials and materials technologies are recognized to be key underpinning and critically enabling areas of R&D. Most industrial sectors and fields of technology application depend upon them. Materials research can provide new solutions capable of optimizing the application of current technologies, minimizing their negative side effects and reducing production costs. However, the long development time and slow return on materials research investments make industry reluctant to take on the associated risks. This alone suggests that policy initiatives to sustain long‐term research efforts are necessary. This article considers the policy findings of national foresight initiatives in the area of materials and material technologies.

This paper aims to shed light on the linkage between research and development (R&D) networks and public funding presented in a given period by using network-based evaluation tools as a means of exploring the relational dimension in public projects designed to foster technology R&D activities.

This research uses co-occurrence network analysis of relevant public projects to assess how technological associations might occur within the R&D activities of given publicly funded projects as well as conducts correlation analysis to understand the extent to which linkages of R&D activity in technology fields are related to public expenditure.

Core technology fields, regarded as eligible to receive continued public funding, are critical for enhancing competitiveness and sustainable growth at the nationally strategic technology level. Thus, the relationship between R&D and the level of government funding for these fields is generally perceived as strong. However, a few technology fields, which did not actively form specific network relationships with other technology fields, are considered to exceptionally drive the largest government support. This trend indicates that the government-funded R&D should be designed and managed not only to curb the inefficiencies existing in the current funding programs but also to achieve the appropriateness for further technology development.

Despite the comprehensive findings, this study has several limitations. First, it is difficult to control any confounding factors, such as the determinants and constraints of the government budget allocation and expenditure decisions over S&T areas, strategic frameworks for public investment and evolving policy landscapes in technology sectors, which lead to bias in the study results. Second, this study is based on a narrow, single-year data set of a specific field of projects supported by the Korean government’s R&D program. Therefore, the generalization of findings may be limited. The authors assumed that influences caused by confounding variables during the initial phase of the public funding schemes would not be significant, but they did not take into account possible factors that might arise coincident with the subsequent phase changes. As such, the issue of confounding variables needs to be carefully considered in research design to provide alternative explanations for the results that have been ruled out. The limitations of this study, therefore, could be overcome by comparing the outcome difference between subsidized and non-subsidized R&D projects or evaluating targeted funding schemes or tax incentives that support and promote various areas of R&D with sufficiently large, evidence-based data sets. Also, future research must identify and analyze the R&D activities concerning public support programs performed in other countries associated with strategic priorities to provide more profound insight into how they differ. Third, there are some drawbacks to using these principal investigators-provided classification codes, such as subjectivity, inaccuracy and non-representation. These limitations may be addressed by using content-based representations of the projects rather than using pre-defined codes. Finally, the role that government investment in R&D has played in developing new science and manufacturing technologies of materials and components through network relationships could be better examined using longitudinal analysis. Furthermore, the findings suggest the need for further research to integrate econometric models of performance outcomes such as input–output relations into the network analysis for analyzing the flow of resources and activities between R&D sectors in a national economy. Therefore, future research would be helpful in developing a methodological strategy that could analyze temporal trends in the identification of the effects of public funding on the performance of R&D activity and demand.

Public funding schemes and their intended R&D relationships still depend on a framework to generate the right circumstances for leading and promoting coordinated R&D activities while strengthening research capacity to enhance the competitiveness of technologies. Each technology field has a relatively important role in R&D development that should be effectively managed and supervised to accomplish its intended goals of R&D budgeting. Thus, when designing and managing R&D funding schemes and strategy-driven R&D relations, potential benefits and costs of using resources from each technology field should be defined and measured. In this regard, government-funded R&D activities should be designed to develop or accommodate a coordinated program evaluation, to be able to examine the extent to which public funding is achieving its objectives of fostering R&D networks, balancing the purpose of government funding against the needs of researchers and technology sectors. In this sense, the examination of public R&D relations provides a platform for discussion of relational network structures characterizing R&D activities, the strategic direction and priorities for budget allocation of the R&D projects. It also indicates the methodological basis for addressing the impact of public funding for R&D activities on the overall performance of technology fields.

The value of this work lies in a preliminary exploratory analysis that provides a high-level snapshot of the areas of metallurgy, polymers/chemistry/fibers and ceramics, funded by the Korean Government in 2016 to promote technological competitiveness by encouraging industries to maintain and expand their competencies.

This study aims to fabricate the acrylic-based polymeric composite coating with a hydrophobic surface associated with natural oil polyol (NOP) and polydimethylsiloxane with the incorporation of 3 Wt.% SiO₂ nanoparticle (SiO₂np) against the corrosive NaCl media.

The structural properties of the formulated polymeric composite coatings were investigated by using Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, water contact angle (WCA) and cross-hatch (X-Hatch) tests. The WCA measurement was used to study the surface wettability of the formulated polymeric composite coatings. The corrosion protection performance of the nanocomposite coated on the mild steel substrate was studied by immersing the samples in 3.5 Wt.% NaCl solution for 30 days using electrochemical impedance spectroscopy.

The enhanced polymeric composite coating system performed with an excellent increase in the WCA up to 111.1° which is good hydrophobic nature and very high coating resistance in the range of 10¹⁰ Ω attributed to the superiority of SiO₂np.

The incorporation of SiO₂np into the polymeric coating could enhance the surface roughness and hydrophobic properties that could increase corrosion protection. This approach is a novel attempt of using NOP along with the addition of SiO₂np.

During the past years, numerous market segments have increasingly adopted additive manufacturing technologies for product development and complex parts design. Consequently, recent developments have expanded the technologies, materials and applications in support of emerging needs, in addition to improving current processes. The present work aims to propose and characterise a new technology that is based on selective formation of metal-polymer composites with low power source.

To develop this project, the authors have divided this work in three parts: material development, process feasibility and process optimisation. For the polymeric material development, investigation of metallic and composite materials assessed each material’s suitability for selective composite formation besides residual material removal. The primary focus was the evaluation of proposed process feasibility. The authors applied multivariable methods, where the main responses were line width, penetration depth, residual material removal feasibility, layer adherence strength, mechanical strength and dimensional deviation of resultant object. The laser trace speed, distance between formation lines and laser diameter were the main variables. Removal agent and polymeric material formulation were constants. In the last part of this work, the authors applied a multi-objective optimisation. The optimisation objectives minimized processing time and dimensional deviation while maximizing mechanical strength in xy direction and mechanical strength in z direction.

With respect to material development, the polymeric material tensile strength was found between 30 and 45 MPa at break. It was also seen that this material has low viscosity before polymerized (between 2 and 20 cP) essential for composite formation and complete material removal. In that way, the authors also identified that the residual material removal process was possible by redox reaction. In contrast with that the final object was marked by the polymer which covers the metallic matrix, protecting the object protects against chemical reactions. For the feasibility study, the authors identified the process windows for adherence between composite layers, demonstrating the process feasibility. The composite mechanical strength was shown to be between 120 and 135 MPa in xy direction and between 35 and 45 MPa in z direction. In addition, the authors have also evidenced that the geometrical dimensional distortion might vary until 5 mm, depending on process configuration. Despite that, the authors identified an optimised configuration that exposes the potential application of this new technology. As this work is still in a preliminary development stage, further studies are needed to be done to better understand the process and market segments wherein it might be applied.

This paper proposed a new and innovative additive manufacturing technology which is based on metal-polymer composites using low power source. Additionally, this work also described studies related to the investigation of concept feasibility and proposed process characterisation. The authors have focused on material development and studied the functional feasibility, which at the same time might be useful to the development of other additive manufacturing processes.

The purpose of this study is for solving many issues in production that includes processing of complex-shaped profile, machining of high-strength materials, good surface finish with high-level precision and minimization of waste. Among the various advanced machining processes, abrasive jet machining (AJM) is one of the non-traditional machining techniques used for various applications such as polishing, deburring and hole making. Hence, an overview of the investigations done on carbon fiber-reinforced polymer (CFRP) and glass fiber-reinforced polymer (GRFP) composites becomes important.

Discussion on various approaches to AJM, the effect of process parameters on the glass fiber and carbon fiber polymeric composites are presented. Kerf characteristics, surface roughness and various nozzle design were also discussed.

It was observed that abrasive jet pressure, stand-off distance, traverse rate, abrasive size, nozzle diameter, angle of attack are the significant process parameters which affect the machining time, material removal rate, top kerf, bottom kerf and kerf angle. When the particle size is maximum, the increased kinetic energy of the particle improves the penetration depth on the CFRP surface. As the abrasive jet pressure is increased, the cutting process is enabled without severe jet deflection which in turn minimizes the waviness pattern, resulting in a decrease of the surface roughness.

The review is limited to glass fiber and carbon fiber polymeric composites.

In many applications, the use of composite has gained wide acceptance. Hence, machining of the composite need for the study also has gained wide acceptance.

The usage of composites reduces the usage of very costly materials of high density. The cost of the material also comes down.

This paper is a comprehensive review of machining composite with abrasive jet. The paper covers in detail about machining of only GFRP and CFRP composites with various nozzle designs, unlike many studies which has focused widely on general AJM of various materials.

The purpose of this study is to manufacture composites from sawdust and polymer high-density polyethylene (HDPE) with different loading from alum as natural and cheap flame retardant and subsequently characterized using standard analytical tools.

Artificial wood plastic composites (WPCs) were prepared by mixing HDPE with sawdust as a filler with constant ratio (2:1) using hot press. Polyethylene-graft-maleic anhydride (PE-g-MAH) used as a coupling agent between two parents of the composites with different ratios (2.5, 5, 7 and 10). Alum as a flame retardant was incorporated into HDPE with 5 phr polyethylene grafted with maleic anhydride (PE-g-MAH) with different ratios (10, 15 and 20). Flame retardant efficiency was investigated using differential scanning calorimetry, thermal gravimetric analysis and the technique of ASTM E162.

The results revealed that the composite containing 5 phr from (PE-g-MAH) exhibited higher mechanical properties and this proved that (PE-g-MAH) act as an efficient coupling agent using the aforementioned ratio. The results also revealed that incorporation of alum as a flame retardant increased the thermal stability of the composites.

Artificial WPCs are ecofriendly materials with a wide range of applications in the constructions field. Moreover, they have high mechanical and physical properties with low cost. Evaluate alum as a natural and cheap flame retardant.

Nanocomposites represent a new prospective branch in the huge field of polymer materials science and technology. It has been shown that an overall enhancement of properties of polymers can be achieved under certain conditions by the addition of nanoparticles. To examine the influence of microstructure on the tribological performance of nanocomposites, different ways of compounding were used in this study. It was found that the friction and wear behavior of polymeric nanocomposites under sliding environment was rather sensitive to the dispersion states of the nanoparticles. When the microstructural homogeneity of the nanocomposites was improved, their wear resistance could be increased significantly. The present work demonstrates the importance of TiO₂‐nanoparticles dispersion in an epoxy resin matrix, on the materials’ tribological properties, when sliding against a smooth steel counterpart.

This paper aims to investigate the flexural properties i.e. the flexural strength and the flexural modulus under the influence of selected input variables, namely; fiber type, fiber loading and fiber size in fabricated natural fiber polymeric composites through using Taguchi’s design of experiment methodology.

The Taguchi’s design of experiment approach has been used to scheme a suitable combination to fabricate the polymeric composites. Pure polypropylene (PP) has been chosen as a matrix material, whereas two types of fibers, namely; wood powder (WP) i.e. sawdust and rice husk powder (RHP), have been used as a reinforcement in the matrix. Microstructure analysis of fabricated and tested samples has also been evaluated and analyzed using a scanning electron microscope. This analysis has divulged that at moderate fiber size and higher fiber loading, no gap or cavities presented between the fillers and matrix particles, which illustrates the good interfacial bonding between the materials.

The flexural strength of the wood powder pure polypropylene (WPPP) composite decreases if the fiber content gets increased beyond 20 Wt.%. In addition, the flexural strength of hybrid composite (WPRHPPP) has been revealed to get improved more in comparison to composites with single fiber as reinforcement. Furthermore, the flexural modulus of WPPP composite has also increased with the increase in fiber loading. It has been concluded that reinforcement size plays an imperative role in influencing the flexural modulus. The optimum parametric setting for the flexural strength and the flexural modulus has been devised as; fiber type – WPRHP, fiber loading – 10 Wt.% and fiber size – 600 µm; and fiber type – WP, fiber loading – 30 Wt.% and fiber size – 1,180 µm, respectively. The microstructure images clearly revealed that during conducted flexural tests, some particles get disturbed from their bonded position that mainly represents the plastic deformation.

The fabricated polymer materials proposed in the research work are green and environmentally friendly.

The natural fiber-based composites are possessing wide-spread requirements in today’s competitive structure of manufacturing and industrial applications. The fabrication of the natural fiber-based composites has also been planned through the designed experiments (namely; Taguchi Methodology- L₉ orthogonal array matrix), which, further, makes the analysis more fruitful and qualitative too. The fabricated polymer materials proposed in the research work are green and environmentally friendly. Shisham WP has been rarely used in the past researches; therefore, this factor has been included for the present work. The injection molding process is used to fabricate the three different polymer composite by varying the fiber weight percentage and fiber size.