scholarly journals A Study Regarding the Mechanical Properties of a Hybrid Matrix with Various Volume Proportions of Dammar

2020 ◽  
Vol 57 (1) ◽  
pp. 133-140
Author(s):  
Dumitru Bolcu ◽  
Marius Marinel Stanescu ◽  
Ion Ciuca ◽  
Cosmin Mihai Miritoiu ◽  
Alin Dinita ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Vibration Mode ◽  
Vibration Damping ◽  
The Other ◽  
Damping Properties ◽  
Elongation At Break ◽  
Hybrid Resin ◽  
Natural Resin ◽  
Volume Proportion

This paper studies the influence of the volume proportion between components on the mechanical behaviour of a hybrid resin obtained by combining the natural resin Dammar and epoxy resin. We analyse three sets of hybrid resin samples, in which we used a Dammar volume proportion of 60%, 70%, and 80% respectively and epoxy resin (employed together with its associated reinforcement in order to generate a quick process of polymerization). Following the tensile test we found the characteristic curves, the tensile strength and the elongation at break for each of the three types of resins. We also looked into the vibration damping properties of bars made of this resin. We experimentally determined the frequency and the damping coefficient of the first particular vibration mode for one bar taken out of each set of resins, with one end fixed and the other free. On the basis of the results, we calculated the loss coefficient for each type of resin.

scholarly journals A Study of Some Mechanical Properties of a Category of Composites with a Hybrid Matrix and Natural Reinforcements

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 478 ◽  
Author(s):  
Marius Stănescu ◽  
Dumitru Bolcu
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Wheat Straw ◽  
Damping Properties ◽  
Hybrid Resin ◽  
Hybrid Matrix ◽  
Natural Resin

The current composite materials must meet a double challenge, one that involves obtaining mechanical properties suitable to the field of activity in which they are used and another one, equally important, that requires that they be renewable. In this paper, we have obtained a category of composite materials that have natural reinforcements (fabrics of flax, cotton, hemp, cattail leaves, and wheat straw). As a matrix, we have used three types of hybrid resin, in the composition of which we used the natural resin dammar, in different majority volume proportions. The differences, up to 100%, were represented by epoxy resin and its associated reinforcement, to generate a quick process of polymerization. We have measured certain mechanical properties and the damping properties of the three types of hybrid resin and of the composite materials under study. Based on these properties, we point out a few fields of activity where these composite materials can be used.

scholarly journals A Study of Some Mechanical Properties of Composite Materials with a Dammar-Based Hybrid Matrix and Reinforced by Waste Paper

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1688
Author(s):  
Marius Marinel Stănescu ◽  
Dumitru Bolcu
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Volume Ratio ◽  
Tensile Tests ◽  
Sem Analysis ◽  
Waste Paper ◽  
Hybrid Resin ◽  
Natural Resin ◽  
Tensile Response

When obtaining environment-friendly hybrid resins made of a blend of Dammar natural resin, in a prevailing volume ratio, with epoxy resin, it is challenging to find alternatives for synthetic resins. Composite materials reinforced with waste paper and matrix made of epoxy resin or hybrid resin with a volume ratio of 60%, 70% and 80% Dammar were studied. All samples obtained have been submitted to tensile tests and Scanning Electron Microscopy (SEM) analysis. The tensile response, tensile strength, modulus of elasticity, elongation at break and the analysis of the fracture surface were determined. The damping properties of vibrations of bars in hybrid resins and in the composite materials under study were also examined. The mechanical properties of the four types of resins and of the composite materials were compared. The chemical composition for a hybrid resin specimen were obtained using the Fourier Transformed Infrared Spectroscopy (FTIR) and Energy, Dispersive X-ray Spectrometry (EDS) analyzes.

scholarly journals Experimental Research into the Mechanical Behaviour of Dammar and Sandarac - Based Bio Resins

2019 ◽  
Vol 56 (1) ◽  
pp. 1-5
Author(s):  
Dumitru Bolcu ◽  
Marius Marinel Stanescu ◽  
Ion Ciuca ◽  
Alin Dinita ◽  
Adrian Rosca ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Epoxy Resin ◽  
Mechanical Behaviour ◽  
Tensile Testing ◽  
Sem Analysis ◽  
Polymerization Process ◽  
Natural Resin ◽  
Volume Proportion ◽  
Reinforcing Material

In this paper, we examine two types of Dammar-based bio resins. In the first type, Dammar alone is used as natural resin, while in the second type a mixture of 70% Dammar and 30% Sandarac is used. Three sample sets were made of each of these resins with a bio resin volume proportion of 55, 65 and 75% respectively, the rest being epoxy resin (used, together with the associated reinforcing material, to generate a quick polymerization process). A SEM analysis is carried out and the surface roughness of each of the studied materials. A series of mechanical properties, determined by tensile testing, are presented. We have determined the characteristic curves, tensile strength and modulus of elasticity and the influence of the epoxy resin volume proportion on the mechanical behaviour of bio resins.

scholarly journals Correlation between Porosity and Electrical-Mechanical Properties of Carbon Nanotube Buckypaper with Various Porosities

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Ling Liu ◽  
Qiaoxin Yang ◽  
Jingwen Shen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Nanotube ◽  
The Other ◽  
Positive Pressure ◽  
Filtration Method ◽  
Elongation At Break ◽  
Conductive Materials ◽  
Wide Range ◽  
Electrical Conductivities

Porous carbon nanotube (CNT) buckypapers (BPs) with various porosities were obtained by using a positive pressure filtration method. The porosity of the BPs fell into a wide range of 11.3–39.3%. Electrical conductivities and tensile mechanical properties of the prepared BPs were then measured and correlated with the porosity of the CNT BPs. Results demonstrated that the conductivities, tensile strength, and elastic modulus of the BPs could decrease by increasing their porosity. The elongation at break of the BPs on the other hand did increase significantly, suggesting improved toughness of the BPs. The obtained electrical conductivity and tensile strength of the porous BPs can reach nearly 0.6 S/m and 26 MPa, respectively, which may be potentially useful in composites reinforcement and conductive materials.

Research on Structure and Mechanical Properties of Epoxy Resin/Clay Nanocomposites by Shock Wave Method

2012 ◽  
Vol 501 ◽  
pp. 366-371 ◽  
Author(s):  
Guang Yi Lin ◽  
Xue Chen Mu ◽  
Dian Wei Qu
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Shock Wave ◽  
Epoxy Resin ◽  
Process Condition ◽  
Interlayer Spacing ◽  
Clay Nanocomposites ◽  
Wave Method ◽  
Optimal Process ◽  
Elongation At Break

Epoxy resin / clay nanocomposites prepared by shock wave method. The structure and mechanical properties including hardness, stress, strain and elongation at break were investigated. XRD was used to observe the interlayer spacing of the OMMT and SEM was used to survey the morphology of nanocomposites system. The results indicated that nano-montmorillonite can effectively increase the mechanical property of the material. The nano-montmorillonite was well dispersed in the epoxy matrix. The optimal process condition is that shock time 5min, nano-MMT content of 5%, duty cycle 1:3, shock depth 3cm.

Topology Optimization of Carbon Nanotube Reinforced Damping Layers

Aerospace ◽  
2005 ◽  
Author(s):  
Arnold Lumsdaine ◽  
Mohan Damu
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Topology Optimization ◽  
Polymer Matrix ◽  
Vibration Damping ◽  
Constrained Layer Damping ◽  
Damping Properties ◽  
Reinforced Polymers ◽  
Damping Material ◽  
Layer Structures

Topology optimization has been successfully used for improving vibration damping in constrained layer damping structures with viscoelastic materials. Reinforcing carbon nanotubes in a polymer matrix greatly influences the mechanical properties of the polymer. Such nanotube-reinforced polymers (NRP) can be used to further enhance the damping properties of the constrained layer structures. The inclusion of nanotubes into a polymer matrix provides a new design variable in the topology optimization studies on such structures. In this work, the topology optimization of structures using such NRP as the damping material is performed. The resulting structures show a phenomenal improvement in damping. Moreover, a more efficient method is used for the optimization process.

Study on the Synthesis and Properties of EP/PU Composite

2011 ◽  
Vol 221 ◽  
pp. 135-139 ◽  
Author(s):  
Xiao Qian Wang ◽  
Zhi Xiong Huang ◽  
Juan Li Zheng ◽  
Qi Lin Mei
Keyword(s):  
Mechanical Properties ◽  
Polyethylene Glycol ◽  
Epoxy Resin ◽  
Ftir Spectrum ◽  
Damping Properties ◽  
Testing Frequency ◽  
Higher Temperature

Isocyanate-terminated polyurethane was synthesized from polyethylene glycol and toluene disocyantes, which was used to modify the epoxy resin. D-230 was chosen as hardener to produce the PU/EP composite. The structure of composite was characterized by FTIR spectrum. Mechanical properties of the epoxy resin with different PU content were studied. Additionally, damping properties of the PU/EP composite were investigated using DMA, and the results showed that the damping properties of EP evidently improved by blending with PU and with the testing frequency increased, the spectra of tanδ-T shifted to higher temperature.

Effect of Corn Straw Addition on Mechanical Properties of Polyvinyl Alcohol Hydrogel

2021 ◽  
Vol 904 ◽  
pp. 250-254
Author(s):  
Shuang Chen ◽  
Jui Chin Chen ◽  
Chi Hui Tsou ◽  
Peng Cheng Yang ◽  
Chun Fen Jia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
The Other ◽  
Corn Straw ◽  
Freezing And Thawing ◽  
Elongation At Break ◽  
Composite Hydrogels ◽  
Freeze Dried ◽  
Freezing And Thawing Cycles

In this study, PVA/CS composite hydrogels were prepared by means of freezing and thawing cycles of agricultural wastes, corn straw (CS) and polyvinyl alcohol (PVA). The mechanical properties of the composite hydrogels were analyzed by universal tensile device. The effects of CS on tensile strength and elongation at break of PVA/CS composite hydrogels were analyzed. On the other hand, PVA and PVA/CS composite hydrogels were also freeze-dried to investigate the mechanical properties of all hydrogels after drying.

scholarly journals Damping properties of para-phenylene terephthalamide pulps modified damping materials

2016 ◽  
Vol 36 (2) ◽  
pp. 137-148 ◽  
Author(s):  
Baihua Yuan ◽  
Meng Chen ◽  
Yu Liu ◽  
Shexu Zhao ◽  
Heng Jiang
Keyword(s):  
Mechanical Properties ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Vibration Damping ◽  
Damping Properties ◽  
Machine Direction ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Damping Property ◽  
Damping Materials

A series of para-phenylene terephthalamide pulp modified damping materials were prepared. The dynamic mechanical properties, differential scanning calorimetry, vibration damping properties, vulcanization property, tensile strengths as well as scanning electron microscopy micrographs of the damping materials were studied theoretically and experimentally. The dynamic mechanical properties of para-phenylene terephthalamide pulp modified damping materials were also compared with aramid short-cut fiber, E-glass staple fiber and carbon fiber powder modified damping materials. The results showed that para-phenylene terephthalamide pulp modified damping materials exhibited the best damping property and highest modulus in comparison with the other types of fibers. The storage modulus ( E′), loss modulus ( E″) and tensile strength of the materials were all increased significantly with increasing pulp content, and this trend was significantly greater in machine direction rather than in cross-machine direction. The second, third and fourth modes modal loss factors (η) of the steel beams coated with para-phenylene terephthalamide pulp modified damping materials increased substantially up to a maximum, and then became stable with increasing pulp amount. The optimal η in machine direction was achieved as the mass ratio of butadiene-acrylonitrile rubber to para-phenylene terephthalamide pulp was 100:30. Excellent damping property was mainly attributed to the extremely high interfacial contact area which significantly improved the efficiency of energy dissipation of internal friction, interfacial sliding and dislocation motion between para-phenylene terephthalamide pulps and butadiene-acrylonitrile rubber chains. Since para-phenylene terephthalamide pulp modified damping materials offer a high E′, excellent vibration damping properties, broad damping temperature and frequency ranges, it is ideal for free-damping structures which are widely utilized in industrial vibration and noise control applications.

The Effect of Masked Isocyanates on the Mechanical Properties of My720/dds Epoxy Resin

1989 ◽  
Vol 171 ◽  
Author(s):  
N. Rungsimuntakul ◽  
S.V. Lonikar ◽  
R. E. Fornes ◽  
R.D. Gilbert
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Moisture Absorption ◽  
Peak Stress ◽  
Fiber Composites ◽  
Elongation At Break ◽  
Initial Modulus ◽  
Better Than

ABSTRACTThe mechanical properties of epoxy resins and epoxy resin/graphite fiber composites are adversely affected by moisture absorption. Incorporation of masked isocyanates that unmask to release isocyanates in situ at the cure temperatures (150-177ºC) reduce the equilibrium absorption up to ∼70%. Dynamic mechanical analyses and stress-strain properties of epoxy resins containing masked isocyanates were examined to determine their effect on mechanical properties. The ultimate Tg of the epoxy is reduced by incorporation of masked isocyanate, but the actual Tg is comparable to the “as cured” Tg of the epoxy. The dynamic moduli up to the Tg are relatively unaffected. Ina number of cases, the initial modulus, elongation at break and peak stress are equal or better than the unmodified resins.

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