scholarly journals The use of image analysis for the interaction of 1,3,5-trisubstituted isocyanurates with oxidizer and different binders in composite materials

2006 ◽  
Vol 60 (3-4) ◽  
pp. 72-77
Author(s):  
Jasmina Dostanic ◽  
Mihela Barbu ◽  
Radmila Jancic-Heinemann ◽  
Tatjana Volkov-Husovic ◽  
Gordana Uscumlic ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Image Analysis ◽  
Polymer Matrix ◽  
Morphological Characteristics ◽  
Morphological Properties ◽  
Bonding Agents ◽  
Grain Color ◽  
The Matrix ◽  
Resin Binder

Composite propellants are non-homogenous propellants and comprise primarily crystalline oxidizer and metal fuels uniformly suspended in a resin binder. The strength of the bonds between the polymer matrix and the oxidizer determine the mechanical properties of composite propellants. In order to achieve good mechanical properties of the fuel, bonding agents are added to the mixture. The role of the bonding agents is to enable good interactions (interphase) between the polymer matrix and the oxidizer grains. The level of interconnection between the phases could be measured by using the surface obtained by cutting the composite material and observing the resulting surface. A problem in the visualization of such a material is to enable the visibility of the polymer matrix and the grains in the image as both phases are white. There are two possible ways to overcome this problem: to add a pigment into the matrix polymer and to color the matrix and make it different from the grain color. Another possibility is to find a solvent for one of the phases and to dissolve one of the phases in an appropriate solvent so that the remaining phase could be stained, photographed and analyzed using the image analysis program. The morphological characteristics of the image could be established and analyzed. The topic of this study was to establish the conditions of preparation of composite propellants containing ammonium per chlorate and HMX and RDX as oxidizers, and polymer of the polybutadiene type and 1,3,5-trisubstituted isocyanurates as bonding agents. The bonding phenomenon was investigated by optical microscopy. The established procedure of preparation will enable the visualization of the composite structure and the morphological characteristics of the surface will be obtained. From the morphological properties of the obtained composite, it will be possible to select a suitable polymer for the preparation of uniformly distributed composite propellant.

The identification of bonding agents for TATB/HTPB polymer bonded explosives

1992 ◽  
Vol 339 (1654) ◽  
pp. 321-333 ◽  
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
High Explosive ◽  
Bonding Agent ◽  
Bonding Agents ◽  
Polymer Bonded Explosives ◽  
Surface Modified

To obtain a polymer bonded explosive (PBX) with acceptable properties it is generally considered necessary to modify the bonding of the filler explosive to the polymer matrix. This is usually achieved by the addition of a ‘bonding agent’. This paper describes an investigation of the interaction of some bonding agents with the surface of the insensitive high explosive l,3,5-triamino-2,4,6-trinitro-benzene. The mechanical properties of the surface modified explosive loaded into a matrix of isocyanate cured hydroxy-terminated polybutadiene have also been studied to elucidate the role of the bonding agent and produce a PBX with high extensibility.

scholarly journals Development and Behavior of Mechanical, Chemical Resistance and Morphology Properties of Silicon/Coir Fiber Reinforced Epoxy Hybrid Composites

2015 ◽  
Vol 59 ◽  
pp. 124-136
Author(s):  
A. Shirish Kumar ◽  
V. Nikil Murthy ◽  
C.B.N. Murthy
Keyword(s):  
Mechanical Properties ◽  
Chemical Resistance ◽  
Hybrid Composites ◽  
Relative Weight ◽  
Continuous Phase ◽  
Morphological Properties ◽  
Core Material ◽  
Coir Fiber ◽  
Reinforced Plastics ◽  
The Matrix

Room temperature cured epoxy was impregnated with coir fiber in order to synthesis composites. Coir fiber is taken in the 3&5% weight in order to suspend on epoxy resin. Two different proportions of Silicon / Coir fiber hybrid composites were prepared by incorporated into the Epoxy as the core material using rule of hybrid mixtures (RoHM). Mechanical properties like flexural strength and modulus, tensile strength and modulus and morphological properties were also studied. Composites were prepared using hand layup technique in presence of hot compression molding technique. The mechanical properties of Silicon / Coir fiber hybrid composites were investigated with reference to the relative weight of Silicon and Coir fiber. The chemical resistance of hybrid composites with and without alkali treatments has been studied. Variation of a fore mentioned mechanical properties and chemical resistance has been studied with different combinations of Silicon and coir fiber as reinforced into epoxy matrix. Fiber, filler reinforced plastics have replaced the metals in Aerospace, Marine, Chemical and Transport industries. Fiber, filler reinforced plastic have gained recognition as structural material. The most important reason for replacing composite materials is that, substantial weight saving can be achieved and strength to weight, and stiffness to weight ratios are superior to the conventional materials of aircraft structures such as aluminum alloy. Composites are materials based on the controlled distribution of one or more materials, termed as reinforcement, in a continuous phase of second materials, called the matrix. The reinforcement is added to provide strength and stiffness to a composite. The matrix is also known as ‘Binder’ material.

scholarly journals Key Role of the Dispersion of Carbon Nanotubes (CNTs) within Epoxy Networks on their Ability to Release

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2530
Author(s):  
Maxime Pras ◽  
Jean-François Gérard ◽  
Luana Golanski ◽  
Guilhem Quintard ◽  
Jannick Duchet-Rumeau
Keyword(s):  
Polymer Matrix ◽  
Interfacial Strength ◽  
Advanced Materials ◽  
Mechanical Reinforcement ◽  
Rheological Analysis ◽  
Polymerization Kinetic ◽  
The Matrix ◽  
Dispersion State ◽  
The Relationship

Carbon nanotube (CNT)-reinforced nanocomposites represent a unique opportunity in terms of designing advanced materials with mechanical reinforcement and improvements in the electrical and thermal conductivities. However, the toxic effects of these composites on human health have been studied, and very soon, some regulations on CNTs and on composites based on CNTs will be enacted. That is why the release of CNTs during the nanocomposite lifecycle must be controlled. As the releasing depends on the interfacial strength that is stronger between CNTs and polymers compared to CNTs in a CNT agglomerate, two dispersion states—one poorly dispersed versus another well dispersed—are generated and finely described. So, the main aim of this study is to check if the CNT dispersion state has an influence on the CNT releasing potential in the nanocomposite. To well tailor and characterize the CNT dispersion state in the polymer matrix, electronic microscopies (SEM and TEM) and also rheological analysis are carried out to identify whether CNTs are isolated, in bundles, or in agglomerates. When the dispersion state is known and controlled, its influence on the polymerization kinetic and on mechanical properties is discussed. It appears clearly that in the case of a good dispersion state, strong interfaces are generated, linking the isolated nanotubes with the polymer, whereas the CNT cohesion in an agglomerate seems much more weak, and it does not provide any improvement to the polymer matrix. Raman spectroscopy is relevant to analyze the interfacial properties and allows the relationship with the releasing ability of nanocomposites; i.e., CNTs poorly dispersed in the matrix are more readily released when compared to well-dispersed nanocomposites. The tribological tests confirm from released particles granulometry and observations that a CNT dispersion state sufficiently achieved in the nanocomposite avoids single CNT releasing under those solicitations.

THE THERMODYNAMICS OF INTERACTIONS AND RELAXATION PROPERTIES OF THE POSS-CONTAINING NANOCOMPOSITES BASED ON POLYURETHANE-POLY(HYDROXYPROPYL METHACRYLATE) MATRIX, WHICH IS FORMED BY THE PRINCIPLE OF IPNS

2021 ◽  
Vol 43 (4) ◽  
pp. 268-279
Author(s):  
L.V. KARABANOVA ◽  
◽  
L.A. HONCHAROVA ◽  
N.V. BABKINA ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Free Energy ◽  
Phase Separation ◽  
Thermodynamic Parameters ◽  
Polymer Matrix ◽  
Methylene Chloride ◽  
Dynamic Mechanical Properties ◽  
The Matrix ◽  
Tan Δ ◽  
Two Peaks

A series of the nanocomposites based on a multicomponent polymer matrix consisting of polyurethane and poly(hydroxypropyl methacrylate) and 1,2-propanediolysobutyl polyhedral oligomeric silsesquioxane (1,2-propanediolysobutyl-POSS), used as a functionalized nanofiller, was synthesized. The polymer matrix was formed on the principle of interpenetrating polymer networks (IPNs). The influence of 1,2-propanediolysobutyl-POSS amount on the thermodynamics of polymer components of the matrix interactions and on the dynamic mechanical properties of the created nanocomposites was studied. With purpose of the thermodynamic parameters interactions calculations the isothermal sorption of methylene chloride vapour by samples was investigated. The methylene chloride vapour sorption by the samples was studied using a vacuum installation and a McBain balance. By calculations of the thermodynamic parameters of PU and PHPMA interactions was shown that the free energy of PU and PHPMA mixing was positive. The introduction of 1-3 wt % of POSS lead to further phase separation in semi-IPNs. This is due to concentration of POSS particles in the PU’s nanodomains. The increasing of POSS content up to 5-10 wt % lead to compatibi-lization in semi-IPNs. These is due to concentration of POSS nanoparticles not only in the PU’s nanodomains but also in the interphase region of semi-IPN. The dynamic mechanical properties of the created nanocomposites were investigated and the degree of polymer components segregation was calculated. It was shown that there are two peaks of tan δ (PU and PHPMA) in the nanocom-posites. The introduction of 1-3 wt % of POSS lead to increasing of tan δ peak of PHPMA and to deepening of the bridge between two peaks (PU and PHPMA). At the same time the degree of polymer components of the matrix segregation became higher. This means the further phase separation in semi-IPNs. Increasing of 1,2-propanediolysobutyl-POSS amount up to 5-10% leads to the concentration of the nanofiller not only in the nanodomains of PU, but also in the interfacial layers. This leads to a change in the free energy of polymer components mixing, which becomes negative. At the same time the degree of polymer components of the matrix segregation became significantly reduced. These means that the process of compatibilization took part in the semi-IPNs.

Characteristics and Properties of Reinforced Oil Palm Frond Fibers (OPFF) in Polyvinyl Alcohol (PVA) Composite for Tubular-Shaped Trays

2015 ◽  
Vol 751 ◽  
pp. 3-8
Author(s):  
Nawapon Sukudom ◽  
Lerpong Jarupan
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Oil Palm ◽  
Morphological Properties ◽  
Degree Of Crystallinity ◽  
Poly Vinyl Alcohol ◽  
Oil Palm Frond ◽  
The Matrix ◽  
Twin Screw ◽  
Palm Frond

Effects on characteristics and mechanical properties of oil palm frond fiber (OPFF) as a reinforced element in poly vinyl alcohol (PVA) were investigated in this study. Series of different loading of OPFF were prepared by the following compositions: 5, 10, 15, 20 and 25 part per resin (phr). Glycerol at 35 phr was also compounded using twin-screw extruder to decrease degree of crystallinity and to reduce shear force of PVA to improve the processability. Injection molding was used to produce specimen for testing. The results indicated that the OPFF has an impact on mechanical properties of the composite material. Different scanning calorimeter (DSC) showed that the melting temperature (Tm) of OPFF reinforced PVA blended with glycerol was shifted to having decrease when compared to the pure PVA. Different loading contents of OPFF indicated that the compressive strength and morphological properties performed by a similar fashion. A highest compressive strength and the modulus of OPFF-reinforced PVA at 25 phr were achieved. Scanning electron microscope (SEM) indicated that OPFF-reinforced PVA at 25 phr yielded no accumulation of OPFF fibers but showed the dispersion in the matrix phase. In conclusion, the OPFF derived from oil palm industry can be used as reinforcement for manufacturing of plant pot in the future stage

Mechanical Properties Of P(S-co-Itana)/P(S-Co-Mana), P(S-co-Ssna)/P(S-co-Mana), And P(S-co-Itana)/P(S-co-Ssna) Ionomer Homoblends

2003 ◽  
Vol 778 ◽  
Author(s):  
Sung-Hwa Oh ◽  
Joon-Seop Kim ◽  
Jeong-A Yu ◽  
Kwanwoo Shin
Keyword(s):  
Mechanical Properties ◽  
Loss Tangent ◽  
Repeat Unit ◽  
Random Copolymer ◽  
Dynamic Mechanical Properties ◽  
Repeat Units ◽  
Ionic Groups ◽  
The Matrix ◽  
Cluster Phase

AbstractThree different sets of styrene-based ionomer homoblends containing ca. 5 mol% of ionic repeat units, i.e. poly(styrene-co-sodium itaconate) [P(S-co-ITANa)]/ poly(styrene-co-sodium methacrylate) [P(S-co-MANa)] ionomer blends, sodium sulfonated polystyrene [P(S-co-SSNa)]/P(S-co-MANa) ionomer blends, and P(S-co-ITANa)/P(S-co-SSNa) ionomer blends, were prepared and their dynamic mechanical properties were investigated. It was observed that with increasing itaconate content in the blend of P(S-co-ITANa)/P(S-co-MANa) ionomers the multiplet of the P(S-co-MANa) ionomer disrupted initially very rapidly, and ionic modulus of the blend increased drastically. In the case of P(S-co-ITANa)/P(S-co-SSNa) ionomer blends, again, the ionic modulus increased significantly with increasing itaconate content. In these two ionomer blend systems, the itaconate, having two ionic groups per ionic repeat unit, influenced the properties of the blends more noticeably than the other two ionic units, containing only one ionic group per ionic repeat unit. In the blend system of P(S-co-SSNa)/P(S-co-MANa), as expected, the cluster loss tangent peak shifted to higher temperature, ionic modulus decreased, but the ionic plateau extended more with increasing the ratio of the P(S-co-SSNa) content. However, it should be mentioned that when the ion contents of the methacrylate and sulfonate ionomers increased to over 6 mol%, at which the cluster phase of the P(S-co-MANa) ionomers is known to become dominant, compared to the matrix phase, the three loss tangent peaks were observed, which implies that methacrylate-rich and sulfonaterich phases exist together. This might be due to the fact that a copolymerization effect becomes stronger; that is, with increasing ion content the role of ionic units in random copolymer ionomers becomes more important, compared to the role of host non-ionic units. As a concluding remark, the properties of these three ionomer blend systems depend on the degree of clustering, type of ionic groups, and the number of ionic groups per repeat unit.

scholarly journals Influence of Thermal Treatment on Mechanical and Morphological Characteristics of Polyamide 11/Cellulose Nanofiber Nanocomposites

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Denis Mihaela Panaitescu ◽  
Raluca Augusta Gabor ◽  
Adriana Nicoleta Frone ◽  
Eugeniu Vasile
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Treatment ◽  
Cellulose Nanofibers ◽  
Morphological Characteristics ◽  
Nanocomposite Films ◽  
Polyamide 11 ◽  
Dynamic Mechanical ◽  
The Matrix ◽  
The Impact

Nanocomposite films were prepared from polyamide 11 (PA11) and cellulose nanofibers (CN) by melt compounding and compression molding. The impact of thermal treatment on the morphology and mechanical behavior of PA11 and nanocomposite films was studied using dynamic mechanical analysis, tensile tests, X-ray diffraction (XRD), and peak force (PF) QNM technique. Slightly higher storage modulus values were obtained for nanocomposites compared to the matrix before the treatment, but a noticeable increase was observed after the treatment. Although CN addition determined increased tensile strength and modulus both before and after the treatment, the increase was much more significant in the case of treated films. The best mechanical properties were shown by treated PA11 films containing 5 wt% CN, with 40% higher Young’s modulus and with 35% higher tensile strength compared to the matrix. Some of the changes pointed out by static and dynamic mechanical tests were explained by the morphological changes determined by the thermal treatment and emphasized by PF QNM and by the increase of XRD crystallinity. A transition from lamellar stack morphology to one involving spherulites was highlighted by AFM. Thermal treatment has proved a valuable method for improving the mechanical properties of PA11/CN composites.

The Role of Sr and TiB on Mechanical Properties of Aluminium 6061 Composites Produced through Stir Casting Route

2018 ◽  
Vol 929 ◽  
pp. 63-69
Author(s):  
Anne Zulfia Syahrial ◽  
Egy Ciptia Putro ◽  
Reza Mohammad Aditya ◽  
Sergi Andiva
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Eutectic Structure ◽  
Stir Casting ◽  
Aluminium Composite ◽  
Grain Refiner ◽  
Maximum Value ◽  
The Matrix ◽  
Sic Composites

Aluminium 6061 composites have been succesfully produced by stirr casting method. The process involved melting aluminium at 800°C and mixed with AlSr, TiB and Mg to produce master alloy of matrix phase, then degassing to remove all of gas entrapped in molten aluminium by argon. There are two types of particles reinforced added into aluminium to produce aluminium composite such as SiC and Al2O3. The particles reinforced addition for both SiC and Al2O3 are started from 2vf-% to 10vf-% to obtain the optimum compostion which have good mechanial propperties. The addition of 10wt-% Mg is to promote wetting between matrix and reinforced while the addition of AlSr and TiB are to improve mechanical properties by modifying the eutectic structure as well as grain refinement of the matrix phases. The two composites are compaired both mechanical properties and microstructure analysis. The mechanical properties of Al/SiC composites such as tensile strength, elongation, and hardness have a maximum value at addition of 10 Vf-% SiC with the value up to 230 MPa, 6.5%, and 62 HRB respectively. While for Al/Al2O3 composites have the highest tensile strength and elongation at 6 Vf-% Al2O3 with the value of 224 MPa and 7% respectively, but the highest hardness is obtained at addition of 10 Vf-% Al2O3 reaches to 55 HRB. The percentages of porosity were increased for both composites along with the increase of particles reinforced. The microstrutures for both composites are similar since they have the same matrix and Sr clearly changed primary Mg2Si become finer chinese scripts, while TiB as grain refiner worked efficiently for higher reinforced particles addition because the grain size reduced for both composites.

scholarly journals Density graded polyethylene foams: Effect of processing conditions on mechanical properties

2019 ◽  
Vol 38 (1-2) ◽  
pp. 3-14 ◽  
Author(s):  
E Cusson ◽  
AH Akbarzadeh ◽  
D Therriault ◽  
D Rodrigue
Keyword(s):  
Mechanical Properties ◽  
Flexural Modulus ◽  
Morphological Properties ◽  
Processing Conditions ◽  
Linear Low Density Polyethylene ◽  
Mechanical Responses ◽  
Blowing Agent ◽  
Significant Difference ◽  
The Matrix ◽  
Different Temperatures

Uniform foams (UF) and density graded foams (DGF) were produced by using similar or different temperatures on both sides of a compression molding system. The samples were produced using linear low density polyethylene as the matrix and activated azodicarbonamide as the chemical blowing agent. Morphological properties of the produced samples were analyzed via scanning electron microscopy to relate them to their mechanical properties. In particular, flexural and impact properties are reported for samples produced under a range of temperatures (140–200°C) and blowing agent concentration (0.7–1.0 wt%). The experimental results showed that a significant difference can be obtained in flexural modulus (up to 17%) and impact strength (up to 48%) depending on the side the stress is applied on. In all cases, the DGF showed better mechanical responses than UF of similar relative density for the range of conditions tested.

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