Mechanical and Thermal Properties

ii ABSTRACT The aim of this study is to study the effect of accelerated thermal aging towards the mechanical and thermal properties of HDPE. Accelerated thermal aging is the method to determine the long-term effects of expected levels of stress within a short period of time. The Q 10 determination using Arrhenius Equation will be determine. The accelerated thermal aging of High Density Polyethylene (HDPE) was studied in air atmospheric pressure and temperature (30°C at room temperature). The changes in elongation at break, hardness of aged material and density as a result of accelerated thermooxidative degradation were followed.

a b s t r a c t The effect of nano-clay platelets (Cloisite 30B) on the mechanical and thermal properties of fly ash geopolymer has been investigated in this paper. The nano-clay platelets are added to reinforce the geopolymer at loadings of 1.0%, 2.0%, and 3.0% by weight. The phase composition and microstructure of geopolymer nano-composites are also investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) techniques. Results show that the mechanical properties of geopolymer nano-composites are improved due to addition of nano-clay. It is found that the addition of 2.0 wt% nano-clay decreases the porosity and increases the nano-composite’s resistance to water absorption significantly. The optimum 2.0 wt% nano-clay addition exhibited the high- est flexural and compressive strengths, flexural modulus and hardness. The microstructural analysis results indicate that the nano-clay behaves not only as a filler to improve the microstructure, but also as an activator to facilitate the geopolymeric reaction. The geopolymer nano-composite also exhibited better thermal stability than its counterpart pure geopolymer.

TIE-31: Mechanical and thermal properties of optical glass 1. Density The density of optical glass varies from 2.39 for N-BK10 to 6.03 for SF66. In most cases glasses with higher densities also have higher refractive indices (e.g. SF type glasses). The density is mainly determined by the chemical composition of the glass. To a small amount the density is influenced by the annealing conditions of the glass near the transformation temperature. Due to the thermal expansion of the glass the density decreases with increasing temperature.

Another potential material as reinfrocing agent for polymers is zeolite. Natural zeolite is microporous crystalline, hydrated alumina silicates of alkaline and alkaline earth element with regular pore structures and high thermal stability [6-7], which imply that addition of zeolite will improve thermal properties of the polymers. In addition, this mineral is resistant to organic solvents, chemicals, and it has high tensile strength and elasticity, as well as hardness which make it resistant to mechanical stress. Furthermore, natural zeolites are abundant and they are considered as low-cost materials.

Received in revised: 29 November 2018 Accepted: 10 December 2018 Available online: 01 May 2019 The work has to develop polypropylene (PP) mixed for the purpose of compatible into the Prosopis juliflora bark powder (PB), Wheat husk carbon powder (WC) and Banyan carbon powder (BBC) using renewable bio resources. PB, WC and BBC were used as filler. They are relatively inexpensive and abundantly available in nature. The waste management were collected the wasted. PB, WC and BBC have been incorporated with composites. The mechanical and thermal studies were carried out to evaluate the effect of filler content on PP. The above filler has been studied for the mechanical and thermal properties increase with an increase in the filler content at optimum level 3% by weight. The tensile property of treated composites shows a higher value than neat PP matrix. The properties has been analyzed the variation value depend upon the porosity of the carbon and mixing the polymer composites.

3. DMSRDE, Kanpur Abstract Natural inorganic filler are added to thermoplastic polymers in a number of situations. The main aim of producing these polymer composites are both the reduction of industrial cost and also modification of certain characteristics such as mechanical properties, HDT and morphological properties. For the enhancement of mechanical and thermal properties, nanofiller particles are added in polymer matrix. Polyether imide (PEI) is an important class of thermoplastics polymer, which are widely used as matrix for the composite materials for high tech applications. The present study is focused to prepare PEI based nano composite incorporated with various loading of PCS coated MWCNT. Mechanical properties results demonstrate a significant improvement in strength, modulus, impact and hardness. The HDT also increases with the incorporation in PEI matrix. Enhancement in mechanical properties and HDT may be attributed to excellent dispersion of PCS coated MWCNT on the entire PEI matrix. Scanning electron microscopy (SEM) results reveal a good interfacial adhesion between PCS coated MWCNT and PEI matrix.

With almost 50 years of research, silicon oxycarbides are not a new class of materials. Yet, some basic concepts regarding the mechanical and thermal properties still need to be unraveled. This circumstance is related to the variability of the SiOC system itself regarding composition (ranging from low carbon- to high carbon-containing samples) and microstructure (ranging from glass to glass ceramic). The governing parameters for these aspects are architecture, composition and chemical bonding of the starting polymeric precursors as well as synthesis parameters like temperature and atmosphere [8, 10-15]. Furthermore, the high-temperature stability of the final SiOC material is not only depending on its chemical composition, architecture of the polymeric precursor and its residual porosity [16] but as well on the chosen furnace (alumina and graphite furnaces yield different results) [17]. Although there is some information on the mechanical and thermal properties of SiOC materials published in literature, the comparability between the different studies is in some cases not fulfilled. Consequently, a systematic study on a series of samples with identical synthesis procedure and well- characterized compositions and microstructures is lacking, however is mandatory to tap the full potential of the system with respect to tailoring the material properties to desired values. The aim of the present study is to systematically assess the mechanical and thermal properties of silicon oxycarbides and to obtain a fundamental understanding concerning the relationship between their phase composition, microstructure and properties. Therefore, a SiOC glass and a series of SiOC glass ceramics with varying compositions were synthesized to address the following objectives:

Keywords: crosslinking; beta rays; micro-indentation; TMA (thermo-mechanical analysis); X-ray; gel content 1. Introduction Material modification is needed in order to obtain better material properties as required in the plastics industry. One of many ways of how to modify polymers is beta radiation crosslinking. In most cases, crosslinked polymers offer better mechanical and thermal properties. The beta radiation sources for the industrial crosslinking of polymers are electron beam accelerators, which allow one to obtain high-radiation doses in a short time [1]. Ionizing radiation (electron beam radiation) can change the macroscopic properties and the molecular structure of polymeric materials. Thermoplastic materials demonstrate better resistance to temperature-induced deformation or flow, and do not melt after the creation of crosslinking bonds. After crosslinking, the impact resistance, chemical resistance, toughness, and thermal stability are all improved [2]. This study focuses on the electron beam crosslinking of various types of polymers. Herein, the individual polymers are described, as are the studies already carried out on their crosslinking by electron beam radiation.

51 4. RESULTS AND DISCUSSION In this study, HNTs were used as nanoclay fillers to improve mechanical and thermal properties of both Keltan 778Z and Keltan 6950 that had different ethylene/propylene ratios (crystallinity) and ENB contents. Test results were evaluated according to two parameters of nanocomposites: amount of HNTs in the nanocomposites and type of EPDMs. Compounds were prepared by using laboratory type two-roll mill. It was realized that whilst of HNTs contents, dispersibility of HNTs was decreasing in EPDM matrix. Due to this problem, maximum amount of HNTs was 40% of EPDM/HNTs compounds. Eight samples that included HNTs with from 0 to 40 phr values were prepared by using two types of EPDMs. Densities of EPDM/HNTs compounds were done to determine weight of samples that would be put into certain volume of basic two plates hot press to cure and mold. The density values of HNTs filled and unfilled Keltan 778Z and Keltan 6950 compounds were between 0.9 g/cm 3 and 1.05 g/cm 3 by using the instrument given in Section 3.2.2.1.

ii ABSTRACT Intermetallic alloy Ni 5 Al 3 is known for its good magnetic and thermal properties as the candidate materials for thermistor applications. A research work on their mechanical and thermal properties study give a better understanding of this system in automotive bodies’ materials. Hardness and corrosion testing were carried out to determine the surface hardness and corrosion rate of Ni 5 Al 3 . There are one non-heat treated and three annealing samples prepared for each test. The annealing temperatures are 300 o C, 500 o C, and 700 o C respectively. The thermal effects on the hardness value and corrosion rate were interpreted. Then, the experimental results were analyzed and compared to the current automobile bodies’ materials. Besides, XRD and EDX inspection were done to mainly investigate the composition of Ni and Al in this alloy. Ni 5 Al 3 is estimated to have hardness of approximately 400 HV and corrosion rate ranging from 5.0 to 30 x 10 -

4. To analyze and compare the results with the current automotive body materials such as mild steel, steel sheet and high strength steel. 1.4 Scope This project involves the determination of the mechanical properties and thermal properties of the intermetallic NiAl material by various types of tests. The raw material will be machined into specify specimens with the parameter in the ASTM.

email: dharam_phy@rediffmail.com (Received on: December 15, 2016) ABSTRACT Using the modified dielectric theory of solids, the electronic, mechanical and thermal properties of many rare-earth mono-nitrides (LaN, CeN, PrN, NdN, SmN, GdN, TbN, DyN, HoN, ErN, TmN, YbN & LuN) are presented here The values of energy gaps such as homopolar gaps (E h ), heteropolar gaps (E c ) and average energy gaps (E p in eV) were evaluated for these binary rare earth semiconducting materials with face centered cubic (FCC) NaCl-type structure. The derived values of average energy gap (E p ) are found to be in excellent agreement with the values obtained from the Penn model. Electronic polarizability was investigated using Chemla’s relation and the investigated values are shown to be in accordance with the results obtained from the Clausius–Mossotti relation. Phillips ionicity (f i ) was evaluated and the obtained values were compared with the values obtained from Tubbs and Pauling’s ionicity model. The evaluated values of crystal ionicity were used to calculate the mechanical and thermal properties such as bulk-modulus (B in GPa) and heat of formation (-ΔH f in Kcal/mol) of these compounds. An excellent agreement has been found between calculated and experimental data as compared to other such theoretical findings. The results for bulk modulus (B) differ from experimental values by the following amounts LaN-0.87%, TbN-2.79%; and the results for Heat of formation (- ΔH f ) differ from experimental values by the following amounts: LaN-0.49%, CeN- 0.03%, PrN-0.90%, NdN-1.39%, SmN-0.35%, GdN-1.12%, TbN-0.51%, DyN- 0.56%, HoN-0.03%, ErN-0.33%, TmN-0.33%, YbN-0.34 & LuN-0.57%.

This study dealt with the mechanical, morphological and ther- mal properties of biodegradable polyester biocomposites contain- ing granulated cork (30 wt.%) processed by extrusion followed by injection moulding. This environmental friendly approach of using a renewable material such as natural cork, promoted a reduction of PLLA and PHBV density resulting in lightweight biocomposites. The mechanical properties shows that the use of cork does not compro- mise significantly the final properties under tensile load and the morphology reveals a good physical bonding of cork to the bio-based polyester matrices. The thermal properties by TGA

[1] Elammaran jayamani, sinin hamdan, md rezaur rahman, muhammad khusairy, "Investigation of fiber surface treatment on mechanical, acoustical And thermal properties of betelnut fiber polyester composites," vol.97, pp.545-554,doi:10.1016/j,proeng. Dec 2014 . [2] M.T. Isa, A.S. Ahmed, B.O. Aderemi, R.M. Taib, I.A. Mohammed-Dabo, "Effect of fiber type and combinations on the mechanical, physical and thermal stability properties of polyester hybrid composites," vol.52,pp.217-223,dx.doi.org/10.1016/j.compositeb.April 2013.

Received: 6 October 2008 / Accepted: 27 January 2009 / Published online: 13 February 2009 Ó to the authors 2009 Abstract Use of sulfur crosslinked nanogels to improve various properties of virgin elastomers was investigated for the first time. Natural rubber (NR) and styrene butadiene rubber (SBR) nanogels were prepared by prevulcanization of the respective rubber lattices. These nanogels were characterized by dynamic light scattering, atomic force microscopy (AFM), solvent swelling, mechanical, and dynamic mechanical property measurements. Intermixing of gel and matrix at various ratios was carried out. Addition of NR gels greatly improved the green strength of SBR, whereas presence of SBR nanogels induced greater thermal stability in NR. For example, addition of 16 phr of NR gel increased the maximum tensile stress value of neat SBR by more than 48%. Noticeable increase in glass transition temperature of the gel filled systems was also observed.

Many important mechanical properties were also inves- tigated including The Izod impact strength was measured using 64 mm long, 12.7 mm wide and 6.4 mm thick specimens on a pendulum impact testing machine ac- cording to the specification, ASTM D 256. The depth under the noch of a specimen is 10.2 mm. Drop height of pendulum was kept 1.46 meter with a striking velocity of 5.35 m/s. Tensile, flexural and compressive properties were measured using a universal testing machine, (Tes tometric, UK), at room temperature at a cross head speed of 5 mm/min, according to the specifications, ASTM 638 - 52, D-790, D -695 , respectively. The Vickers hard ness number (VHN) was calculated using micro-hardness testing instrument manufactured by M/s. Frank, UK. For hardness measurement at ambient conditions, films of uniform thickness (0.8 - 1.0 mm) were used. The hard ness of a material was measured by forcing an indenter into the surface of the film with a constant speed. A force of 2.94N was applied slowly by pressing the indenter at 90 o into the material surface being tested. The indenter material, in the form of square based pyramid made up of diamond was used for indentation. The indentation time was kept fixed (i.e. 30 seconds) for all samples. An em- pirical hardness number was then calculated by measur- ing the length of the diagonal through microscope at- tached with the instrument. To evaluate the effects of HTPB contents on the degradation behaviour of modified epoxies at various temperatures, thermogravimetric analy- sis was conducted on a Perkin Elmer Diamond TGA/

directly next to a microwave structure 100µ m × 1.5µ m compared to a ∼ 50µ m wire. Deposition of the microwave structure can be performed using thermal or e-beam evaporation techniques, the patterning can be achieved using optical lithography, e-beam lithography or shadow mask techniques. Due to its simplicity this work routinely used thermal evaporation and a shadow mask. The shadow masks used throughout this thesis were cut out of thin hardened steel plate using a wire cutting EDM machine. The resolution of this machine was limited to about 100 µm cuts, which was not ideally small enough but sucient to get a considerable improvement in ODMR signal. Another approach investigated was to use a femto-second pulsed IR laser to ablate thin steel plate to create a shadow mask. This approach has showed feature sizes of ∼ 30µ m and is relatively simple to perform and will be investigated more into the future. The deposition process consists of mounting the sample on a silicon wafer within a surrounding metal piece the same thickness as the diamond to mount the shadow mask upon. The sample, mask and silicon wafer were plasma cleaned in 100 W O2 plasma for 15 seconds. Then a 10 nm layer of Ti was thermally deposited by 1.5 microns of Cu also thermally. An example structure is shown in gure A.6

Figure 3. Strain at break of PC/ABS blends as a function of the PC content. 3.2. Flexural Properties Both the flexural modulus and the strength of the blends have been measured. In Figure 4, the values of the flex- ural elastic modulus measured in three-point bending exhibit a clear positive deviation from linearity, that is, a synergistic behavior. Thus, all the E values obtained for the blends with 60%, 70%, 80% and 90% PC are higher than those obtained for the pure components of the blends. It can be supposed that the component of highest modulus contributes to the resulting value in a greater extent than the corresponding to the composition. The stress or strain concentrations in the matrix may give rise to increased local contributions to the overall stress with respect to that which corresponds to the composition of the blend [6]. Synergistic behavior in the modulus of polymer blends in relation with composition has been explained in some cases as a consequence of the blend densification, due to interactions between the compo- nents [6]. In Figure 5, the flexural break stress appears to vary gradually and monotonically with the PC content, while a significant decrease in the strain is observed in Figure 6. However, a maximum strain value is again obtained for the blend with 90% PC.

the fibre-matrix mixing process. Extreme care was taken to achieve a uniform matrix distribution throughout the fi- bre cross-sections in the sample and removed any possible entrapped air in the matrix. Then the second layer of jute fabric was placed on the top of the first layer and above pro- cess was repeated. Afterwards, a waxed flat glass plate was placed on the top of the mat with a weight to ensure smother surface of the fabricated composites. The fibre content was 25% of the weight of the produced samples. The samples were kept at room temperature overnight then post cured at 80°C for 4 hours. The sample was released from the mould and kept in an oven at 80°C for 4 hours to post-cure. The cured panel (400 × 400 mm 2 ) was trimmed and sectioned for mechanical testing.

Thirdly, the thermal conduction of raw silk layers was investigated via Laser flash (LFA). It demonstrated that the innermost layer has a higher thermal conduction than the outermost layer, and the main contributor to thermal conduction of raw silk cocoon is calcium oxalate crystals followed by sericin layer. The thermal conduction of single fibres was also studied. It was observed that thermal conduction exhibited strong anisotropy in transverse and longitudinal directions, with higher thermal conductivity in the longitudinal direction. Thermal conduction in longitudinal direction is affected by crystallite size. The crystallites size in the directions of β-sheet stacking and β- strand direction had a tendency to increase the thermal conduction of A. pernyi outermost fibres, whereas increasing β-sheet stacking and the number of chains can increase thermal conduction of A. pernyi innermost fibres. The high mean free path of phonon from innermost fibre promoted its high thermal transfer in longitudinal direction. The nano pores inside A. pernyi silk fibres are enclosed pores, and have a negative effect on the heat transfer in the longitudinal direction due to the high inclination degree of the nanocrystallites. With the inclination degree of 90°, the average thermal transfer was attributable to the hydrogen bonds instead of chain direction.