Characterization of Minerals, Metals, and Materials: Soft Materials
Sponsored by: TMS Extraction and Processing Division, TMS: Materials Characterization Committee
Program Organizers: Shadia Ikhmayies, Al Isra University; Bowen Li, Michigan Technological University; John Carpenter, Los Alamos National Laboratory; Jian Li, CanmetMATERIALS; Jiann-Yang Hwang, Michigan Technological University; Sergio Monteiro, Military Institute of Engineering ; Firrao Donato, Collegio Universitario, Italy; Mingming Zhang, ArcelorMittal Global R&D; Zhiwei Peng, Central South University; Juan P. Escobedo-Diaz, UNSW Australia; Chenguang Bai, Chongqing University; Eren Kalay, METU; Ramasis Goswami, Naval Research Laboratory; Jeongguk Kim, Korea Railroad Research Institute

Monday 8:30 AM
February 27, 2017
Room: 31B
Location: San Diego Convention Ctr

Session Chair: Sérgio Monteiro, IME; Andrew Brown, UNSW Canberra

8:30 AM  Cancelled
Analysis of the Elastic Properties and Reaction Kinetics of an Epoxy Resin Polymer during Cure Relaxation: Manon Heili1; Andrew Bielawski2; John Kieffer2; 1University of Michigan ; 2University of Michigan
    The cure kinetics of the epoxy-based polymer DGEBA/DETA is investigated using concurrent Raman and Brillouin light scattering. Raman scattering allows monitoring the in-situ reaction and assess the degree of cure, while Brillouin scattering yields the material’s elastic properties, providing a measure of the network connectivity. We show that the polymer’s adiabatic modulus evolves non-uniquely as a function of cure degree, depending on cure temperature and molar ratio of the epoxy system. Two mechanisms contribute to the increase in the elastic modulus of the material during curing. Firstly, the network forms covalent bonds while curing. Secondly, following the bond formation, the structure undergoes structural relaxation toward an optimally packed network configuration. We investigate to what extent the non-bonded interaction contribution to structural rigidity in cross-linked polymers is reversible, and to what extent it corresponds to the difference between adiabatic and isothermal moduli obtained from static tensile, i.e., the relaxational modulus.

8:50 AM  
Charpy Toughness Behavior of Fique Fabric Reinforced Polyester Matrix Composites: Artur Camposo Pereira1; Foluke Salgado de Assis1; Sergio Neves Monteiro1; Henry Colorado2; 1Instituto Militar de Engenharia; 2Universidad de Antioquia
    The fique fiber is an important natural fiber, originally from Colombia where it is used for sacks and crafts while its plant is used to contain slopes. However, few studies were realized with the fiber obtained from the fique plant leaf, its mechanical properties are superior in many aspects in comparison to some other lignocellulosic fibers. This work investigated the toughness behavior of polyester matrix composites reinforced with up to 30% in volume of a fabric made of fique fiber by means of Charpy impact tests. It was found that the addition of fique fabric results in a marked increase in the absorbed energy by the composites. Macroscopic observation of the post-impact specimens and SEM fracture analysis showed that transversal rupture through the fique fabric interface with the polyester matrix is the main mechanism for the remarkable toughness of these composites.

9:10 AM  
Comparative Analysis of Curaua Fiber Density Using the Geometric Characterization and Pycnometry Technique: Natália Maciel1; Carolina Ribeiro1; Janaina Vieira1; Jordana Ferreira1; Frederico Margem1; Carlos Maurício Vieira1; Sérgio Monteiro2; Cláudio Roberto Marciano1; 1UENF; 2IME
    One of today's biggest concerns has been environmental issues, which has motivated researches and development of materials from renewable resources and environmentally friendly. From this idea, natural fibers have excelled in replacing synthetic fibers used in composites manufacturing. However, the natural fibers have irregularities and pores in its structure, which directly impacts the density determination by geometric techniques and, accordingly, the volume of fibers used in composites. Therefore, this study has as main objective to determine the density of curaua fiber bypycnometry and to compare it with the geometric technique that is commonly used.

9:30 AM  
Izod Impact Tests in Polyester Matrix Composites Reinforced with Blanket of the Malva and Jute Fibers: Carolina Ribeiro1; Frederico Margem2; Jean Margem3; Sérgio Monteiro4; Ygor de Moraes1; João Batista Gomes3; 1State University of the Northern Rio de Janeiro; 2Faculdade Redentor; 3ISECENSA; 4Instituto Militar de Engenharia
    The lignocellulosic fibers are considered a potential replacement for the search field of synthetic fibers, particularly glass fiber. The use of natural fibers to replace the existing is motivated by several advantages such as good toughness, low cost and light weight. In addition, unlike the glass fibers lignocellulosic fibers are relatively flat and the processing procedures produce less wear on equipment. The environmental issue is another point in favor of natural fibers, which are renewable, recyclable, biodegradable and neutral with regard to CO2 emissions. The objective of this work was to assess the Izod impact resistance of polymeric composites reinforced with blanket of malva and jute fibers, up to 30% in volume. The results showed a remarkable increase growing in the notch toughness with the increase of volume fraction. This can be attributed to a preferential debonding of the fiber/matrix interface, which contributes to an elevated absorbed energy.

9:50 AM  
Tensile Behavior of Epoxy Matrix Composites Reinforced with Eucalyptus Fibers: Caroline Gomes de Oliveira1; Anna Carolina Cerqueira Neves1; Gilson Vieira Fernandes1; Marcos Vinícius Fonseca Ferreira1; Frederico Margem Muylaert2; Sérgio Neves Monteiro3; 1UENF - Universidade Estadual do Norte Fluminense; 2Faculdade Redentor; 3Instituto Militar de Engenharia
    Natural fibers represent an economic and environmental motivation for replacing the synthetic fibers, mainly as composite reinforcement material, which is one of their major applications. Some advantages of the natural fibers are the biodegradability, low cost and renewability. Among the natural fibers, the lignocellullosic ones are highlighted for their high resistance. One of the lignocellullosic fibres most cultivated in Brazil is the Eucalyptus fibers, extracted from the stem of Eucalyptus citriodora. In this work, it was investigated the tensile behavior of the epoxy matrix composites reinforced with different volume fractions of Eucalyptus fibers. The specimens were made by pouring the still liquid resin into the mold and laying the fibers onto the resin. The results show a decrease in the tensile resistance with the increase of volume fraction. It is due to the low adhesion between the fibers and the matrix.

10:10 AM Break

10:25 AM  
Izod Toughness Behavior of Continuous PALF Fibers Reinforced Polyester Matrix Composites: Gabriel Glória1; Giulio Altoé2; Maycon Gomes3; Maria Carolina Teles1; Frederico Muylaert1; Carlos Mauricio Vieira1; Sérgio Monteiro4; 1State University of the Northern Rio de Janeiro; 2Pontifícia Universidade Católica do Rio de Janeiro; 3Instituto Federal Fluminense; 4Instituto Militar de Engenharia
    Due to growing concern about the ambiet impacts, the society is demanding for materials that are environmentally friendly. The lignocellulosic fibers, like PALF fibers, appears like na option to substitute the synthetic ones in composites with polimerics matrices. Besides the environmental advantages, the lignocellulosic fibers have economical and some properties advantages like the low density in comparison with the synthetic fibers. Nowadays the lignocellulosic are used in industries, like the automobile and aerospace. This objective of this study was to analyze the absorbed impact energy of the composites reinforced with PALF fibers. The fibers were incorporated into the polyester matrix with volume fraction from 0 to 30%. The results showed increased in the absorbed impact energy with the increase of the percentage of fiber incorporated. After the fracture the specimens were analyzed by SEM (scanning eléctron microscope) and indicates that the PALF fibers act as reinforcment for the polyester matrix.

10:45 AM  
Mechanical, Thermal, Morphology and Barrier Properties of Flexible Film Based on Polyethylene-ethylene Vinyl Alcohol Blend Reinforced with Graphene Oxide: Julyana Santana1; Angel Ortiz1; Rene Oliveira1; Vijaya Rangari2; Olgun Güven3; Esperidiana Moura1; 1Instituto de Pesquisas Energéticas e Nucleares; 2Tuskegee University; 3Hacettepe University, Department of Chemistry, Polymer Chemistry Division
    Ethylene-vinyl alcohol (EVOH) copolymers are widely used in the food packaging industry as gas barrier properties to oxygen, organic solvents, and food aromas. EVOH is very sensitive to moisture and its gas barrier ability deteriorates in high relative humidity conditions. This work aims to prepare flexible films based on melt-blending high density polyethylene (HDPE) and ethylene-vinyl alcohol (HDPE/EVOH/EVA blend) reinforced with graphene oxide (GO). The HDPE/EVOH/EVA/GO flexible films were prepared by twin-screw extrusion and blown film extrusion processing. The flexible films samples were characterized by tensile tests, TG, DSC and FE-SEM analysis and the correlation between properties was discussed. In addition, the oxygen permeability tests were performed at 23 C, 0 % and 90 % relative humidity using an OX-TRAN (MOCON Inc.).

11:05 AM  
Izod Impact Tests in Epoxy Matrix Reiforced with Fique Fibers: Maria Carolina Teles1; Sérgio Monteiro2; Djalma Souza1; Frederico Margem3; 1State University of the Northern Rio de Janeiro; 2Instituto Militar de Engenharia; 3Faculdade Redentor
    Modern composite materials, especially those reinforced with synthetic fibers such as glass and carbon, have been used since last century to attend the demands required by most technological fields. Even though the high-tech composites still stand as top competitors, in their areas, the simpler glass fiber composites are now being replaced by natural fiber composites. Environmental , economic and technical reasons favor increasingly synthetic fiber replacement by natural fibers , mainly those extracted from lignocellulosic plants. The objective of this work was then to assess the Izod impact resistance of polymeric composites reinforced with different amounts,up to 30% in volume of strength natural fiber, the Fique fiber. The fibers were embedded in Pressure epoxy resin matrix cured at room temperature for 24 hours. The Specimens were tested in Izod impact pendulum and surfaces fracture analyzed by scanning electron microscopy. Impact resistance increased linearly with the amount Fique fiber, reinforcing composite.

11:25 AM  
Radiation Effects on Crosslinking of Butyl Rubber Compounds: Sandra Scagliusi1; Elizabeth Cardoso1; Ademar Lugao1; 1IPEN
    When butyl rubbers are subjected to high energy radiation, they form easy free radicals that initiate various chemical reactions. These reactions alter the molecular distribution of irradiated rubbers by crosslinking or scission affecting their physical and mechanical properties. The aim of this work is the analysis of effect induced by -exposure on the crosslinking density in butyl rubbers by swelling measurements accomplished before and after irradiation at 5, 25, 50, 100, and 200 kGy, with further evaluation of crosslinking density accomplished by Flory-Rehner equation that is a proper procedure for the qualification of radiation resistance. It can be noticed that changes in material structure was due to build-up of new three-dimensional network in studied rubbers. The change in crosslinking density of butyl rubber compounds emphasizes that degradation mechanism is strongly influenced by irradiation doses higher than 50 kGy, since chain scission process predominates over crosslinking reaction.

11:45 AM  
Viscoelastic Properties of Human Dental Pulp Tissue: Burak Ozcan1; Ece Bayrak1; Cevat Erisken1; 1TOBB University of Economics and Technology
     This study aims to characterize the linear viscoelastic material functions and compressive properties of dental pulp tissue obtained from human wisdom teeth using small-amplitude oscillatory shear and uniaxial compression. These properties were also compared with the properties of hydrogels (agarose, alginate, collagen), that are widely used as biomaterials in tissue regeneration. Comparisons revealed the gel-like behavior of the pulp tissue over a relatively large range of time-scales (over the frequency range of 0.1–100 rps). At the constant gelation agent concentration of 2%, the dynamic properties, i.e., storage and loss moduli and the tan delta, of the agarose- and alginate-based gels were similar to those of the human pulp tissue. Under uniaxial compression, the peak normal stresses and compressive moduli of the human pulp tissue exhibited significantly higher compressive properties than those of the hydrogels. Findings provide valuable inputs for the selection of an appropriate biomaterial for dental pulp regeneration.

12:05 PM  
The Dimensional Characterization of Jute Fabric Strips for Reinforcement in Composite Polymeric: Frederico Margem1; Sergio Monteiro2; Vinícius de Oliveira Barbosa3; Glênio Fernando Daniel3; André Raeli Gomes3; Victor Barbosa de Souza3; 1UENF; 2IME; 3Redentor
    Nowadays notorious technological growth is encouraging research natural materials in substitution to more usual synthetic ones. One of those initiatives is the vegetable fibers that have been studied for the replacement of glass and carbon fibers. This research addresses broadly the study of the natural fibers mechanics properties, but none study have been made with natural fabrics, such as the pure jute fabric used in Brazil to make ropes and carpets. This work aim to evaluate the mechanical behavior of jute fabric strips with different dimensions to be used as reinforcement into polymeric composites Lots of those fabric strips were subjected to tensile tests in order to obtain the tensile resistance for each strip size. The results obtained during the tests were satisfactory and indicated that 100 x 126 x 3 mm correspond to the best result and the perfect fabric strip for the composite reinforcement.