Manufacturing Of Polymer Matrix Composites Research Articles

Morphological, chemical and mechanical properties of hybrid polyester composites reinforced with bamboo fibers and kaolin waste

This article presents a study on the use of natural fibers and kaolin waste as sustainable alternatives in the manufacture of polymer matrix composites. In the present research, isophthalic unsaturated polyester matrix composites were manufactured in association with bamboo fibers (Bambusa vulgaris) and kaolin waste. The kaolin waste was used with a particle size of 50–100 MESH and the fibers in lengths of 15 mm and 30 mm, randomly arranged within the matrix. Bamboo fibers were used fresh and treated with NaOH (5%/2 h). The chemical characterization of the fibers was obtained followed by the morphological characterization using Scanning Electron Microscopy (SEM). The composites were mechanically evaluated through flexural and tensile tests. The mechanical properties obtained were treated by analysis of variance (ANOVA) and Tukey test. The fracture surfaces of the composites were verified by SEM. Bamboo fibers had a chemical composition similar to other natural fibers already studied, with 7.55% extractives, 17.95% total lignin and 74.5% holocellulose. Composites with 30 mm long treated fibers and 30% kaolin showed better flexural strength (137.0 MPa), with deformation of (1.59 mm) and flexural modulus of (19.27 GPa). Through tensile tests, it was possible to identify that the addition of kaolin waste provided a significant improvement in tensile strength of 66% (15BTKW20) and 54% (30BTKW20) compared to neat polyester. SEM micrographs of bamboo fibers, surface roughness, starch granules, micropores and parenchyma cells were identified. ANOVA reinforced the reliability of the results, highlighting the feasibility of manufacturing kaolin waste/bamboo fiber hybrid composites.

Carnauba leaf fibers: correlation among diametrical variation, physical and mechanical properties

The variability of properties presented by natural lignocellulosic fibers (NLFs) is an important issue to highlight, since such inconsistencies in their characteristics put them at a disadvantage when comparing them to synthetic materials. It is important to point out that the application of methodologies that make it possible to predict the behavior of NLFs in the face of mechanical stress is essential for the use of these materials in engineering applications. For this, the present study proposes to evaluate the influence of the carnauba fibers (Copernicia prunifera) morphology in the properties presented by these materials. Optical microscopy (OM) was applied to determine the cross-section and diametrical variation of the fibers, enabling the evaluation of density by Archimedes method according to the mean diameter of the fibers. The mechanical properties were evaluated by tensile testing and the data were acquired by Weibull analysis. The morphological aspects of the longitudinal and cross-sections of the fibers were evaluated with scanning electron microscopy (SEM). The fibers had an average density of 1.13 ± 0.22 g/cm3, with diameter intervals ranging from 0.31 to 1.21 mm. The fibers have reasonable mechanical properties, with an average tensile strength of 64.7 ± 40.9 MPa, Young's modulus of 1.37 ± 0.80 GPa and elongation of 5.59 ± 1.60%. The SEM micrographs highlighted the defects present on the outer surface of the fiber as well as in the cross-section. There was a high potential for the use of carnauba fibers in the manufacture of polymer matrix composites.

A Short Review on: Recent Advances in the Use of Carbon Nanotubes in Additive Manufacturing of Polymer Matrix Composites

AbstractThe multi‐functionality of polymer matrix composites, proposes remarkable merits over metals including more stiffness and strength, lower weight, higher resistance to corrosion, and fatigue, etc. Furthermore, the next generation of production undergoes a revolution by increasingly progresses in additive manufacturing. There have been a large group of materials that can be exploited for this fashionable fabrication technique, although, polymer matrix composites are a significant class of material that have recently been used in additive manufacturing. The mixture of these polymers with nanofillers such as carbon nanotube improves mechanical, thermal, and electrical conductivity properties. This short review summarizes relevant production techniques, carbon nanotube polymer matrix composites, and performed research on its application for additive manufacturing.

A novel manufacturing route for integrated 3D-printed composites and cold-sprayed metallic layer

ABSTRACT Polymer matrix composites (PMCs) are the most used in aerospace fields due to their special mechanical properties coupled with reduced weight. Metallic structures can be manufactured on the surface of PMCs producing hybrid constructions with intriguing characteristics. The cold spray technology (CS) seems to be the best solution for the manufacturing of metallic coatings on polymer-based substrates. However, the last researches on PMCs metallization through CS were carried out without taking into account a proper manufacturing of the substrates. Therefore, the customized manufacturing of PMCs used as substrates for CS deposition represents a crucial aspect to be considered, the target surface should be designed and manufactured to fit better the CS requirements. In this scenario, the Fused Filament Fabrication method (FFF) is the best solution for tailored composites manufacturing. Therefore, this work aims to develop a novel manufacturing route to produce innovative composite structures by using the FFF technology for the 3D-printed polymer-based substrate and the cold spray technology for the 3D-printed metal deposition. The novelty is that, for the first time, the polymer-based substrates will be designed and manufactured “ad hoc” for the cold spray metallization by using the rapid prototyping 3D-printing process successfully integrated with CS technology.

Study of Internal Response of Epoxy due to Compressive Load via Experiment and Simulation Using Abaqus FEA Software

Epoxy is widely used primarily as a matrix material in the manufacture of Polymer Matrix Composites (PMC). Epoxy behavior under compression load has to be understood before the mechanical behavior of PMCs can be accurately predicted. Simulation model combined with experiment and image analysis are used to investigate internal response of epoxy resins polymeric materials subject to compressive loads. To investigate epoxy response to compressive load, small carbon-based material rods are inserted in the epoxy. The samples are held in one side and subjected to compressive load on the other side. All the samples swell at load sides. Image analysis on the carbon-based rods figures out the internal response, which seems to be isotropy in lateral direction. The results are compared to simulation results using Abaqus FEA. Similar condition is obtained when a brittle thin material is stuck to the top of the model.

Polymer characterization by ultrasonic wave propagation

AbstractThe propagation of low‐intensity ultrasound in polymers, acting as a high‐frequency dynamic mechanical deformation, can be successfully used to monitor changes in the modulus of polymers associated with glass transition, crystallization, cross‐linking, and other chemical and physical phenomena related to changes in the viscoelastic behavior, such as gelation phenomena. The velocity of sound is related to the polymer storage modulus and density, whereas the absorption of ultrasonic waves is related to the energy dissipation in the material and, therefore, to the loss modulus. Accordingly, ultrasonic measurements have been used by several authors to monitor the evolution of the viscoelastic moduli of polymers as a function of time or temperature and, recently, become a characterization technique of its own right, generally known as ultrasonic dynamic mechanical analysis (UDMA). Often the technique is used in conjunction with rheological methods as a means of providing a better insight into the viscoelastic behavior of polymer systems. As yet UDMA is underutilized primarily because of the low operating temperatures (usually below 100○C) of commercially available ultrasonic transducers, and also due to the requirement of a coupling medium to ensure an efficient energy transfer mechanism between the transducer and the test material. Despite these limitations, this paper shows that the use of ultrasonics is potentially a powerful method for the characterization of polymers, particularly as a tool for online monitoring of events occurring during polymer processing and in the manufacture of polymer matrix composites. The aim of this paper is to review the progress made in recent years, highlighting the potential and reliability of UDMA for monitoring physical transitions in polymers such as glass transition, melting, crystallization, as well as physical changes taking place during curing of thermosetting resins. © 2009 Wiley Periodicals, Inc. Adv Polym Techn 27:63–73, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20124

Progress in Processing and Performance of Porous‐Matrix Oxide/Oxide Composites

All‐oxide continuous fiber‐reinforced ceramic matrix composites are enabling materials for high‐temperature structural applications in oxidizing environments. However, their industrial use requires further improvements in material performance as well as a significant reduction of the processing costs. This article gives some insight into a novel colloidal processing route. A porous mullite matrix was designed to obtain damage‐tolerant behavior as well as high‐temperature long‐term stability. Laminated composites were formed with conventional techniques similar to the manufacture of polymer matrix composites. This simple and low‐cost process leads to homogeneous microstructures with improved material properties compared with the state of the art in continuous fiber‐reinforced oxide/oxide composites. The developed composites in the present study exhibit favorable mechanical properties both at room temperature and after thermal aging for 1000 h at temperatures up to 1300°C.