Melting Temperature Of Composites Research Articles

Utilization of Silica Filler as Reinforcement Material of Polylactic Acid (PLA) in 3D Printing Applications: Thermal, Rheological, and Mechanical Performance.

Glass was introduced as an additive to filaments used for the manufacturing of composite materials, employed by Additive Manufacturing applications. Glass accounts for a large waste electric and electronic equipment (WEEE) percentage, and its recovery and recycling can lead to the production of sustainable composite materials. In this work, poly(lactic acid) (PLA)/commercially available silicon oxide composite filaments were manufactured and their structural, thermal, rheological, and mechanical properties were assessed. Scanning Electron Microscopy confirmed the 1:2 ratio of silicon: oxygen, along with the relatively low adhesion between the filler and the matrix. Differential Scanning Calorimetry presented steady glass transition and melting temperatures of composites, whereas a crystallization temperature of 10% wt. and a crystallinity of 15% wt. composite slightly increased. Rheological analysis showcased that the viscosity of the composite filaments decreased compared to PLA (10-100 compared to 300-400 Pa·s), with a more shear-thinning behavior. Dynamic mechanical analysis exhibited increased elastic, flexural moduli, and flexural strength of composites (up to 16, 23, and 11%, respectively), whereas tensile strength and elongation decreased. The affordability of raw materials (with the future introduction of recycled ones) and the minimal processing steps can lead to the potential scaling up of the study.

Thermal, mechanical, morphological, and structural properties of composites based on polyolefin and biofiller produced from snail shell (PP/SSP)

Polypropylene (PP) and its composites have excellent fluidity, mechanical properties, weather resistance, chemical strength, and are economical. Additionally, they are very popular and widely used in various applications such as automotive, construction, and consumer goods. This study shows the injection molding process of specimens and the effect of snail shell powder (SSP) produced by the mechanochemical processes in the polypropylene matrix in terms of mechanical, thermal, structural, and morphological analysis using Traction and Hardness test, differential scanning calorimetry (DSC), Fourier transformation infrared (FT-IR), and optical microscopy (OM). As a result, the thermal analysis indicates that by increasing SSP. When compared to pure polypropylene, the melting temperature of composites PP/SSP-5 decreased while the crystallization temperature increased. Thus, the degree of crystallinity decreased. In addition, the mechanical properties were improved by increases in Young’s modulus of 11% and decrease in stress and elongation at break of 81% and 54%, respectively. While the tensile strength fluctuates with the loaded SSP. Also, the toughness of the PP/SSP-10% composites showed a decrease of 81% compared to the pure PP. Furthermore, structural analysis using Fourier transformation infrared (FT-IR) confirms the combination of SSP and PP. Optical microscopy confirms the obtained results by demonstrating a good distribution of SSP in the PP matrix. We can confirm that SSP improves the properties of PP and can be used as an environmentally friendly and renewable filler.

Effect of Maleic Anhydride Grafted Ethylene Vinyl Acetate Compatibilizer on the Mechanical, Thermal Properties and Weathering Resistance of Polyamide 11/Bamboo Fiber Composite

In this research, short bamboo fiber (BF) has been used as filler in the fabrication of the composite based on polyamide 11 (PA11) by melt-mixing method. In order to improve the compatibility between BF and PA11, maleic anhydride grafted ethylene vinyl acetate copolymer (EVAgMA) was introduced into the composite preparation process. The effect of EVAgMA contents on mechanical, thermal or weathering resistant properties of the composites was investigated. In the presence of the EVAgMA, the tensile strength, impact strength and flexural modulus of composites showed the improvement in comparison to without compatibilizer. Differential scanning calorimetry (DSC) analysis indicated that the melting temperature of composites did not depend on the EVAgMA contents, while its fusion heat (ΔHm) decreased with increasing EVAgMA contents. Dynamic mechanical thermal analysis (DMTA) evaluated the role of EVAgMA on the enhancement of composites’s storage modulus (G′) in the glassy plateau and the interaction between BF and PA11 matrix. After 840 hours of accelerated weathering test, the composites using EVAgMA were decomposed faster than that of neat PA11 and PA11/BF composite. This result was also agreed with the observation of scanning electronic microscopy (SEM) images and the change of carbonyl index (CI). However, the retention of tensile properties of PA11/EVAgMA/BF composites is higher than that of PA11/BF composite.

Determination of Some Technological Properties of Injection Molded Pulverized-HDPE Based Composites Reinforced with Micronized Waste Tire Powder and Red Pine Wood Wastes

In this study, the effects of micronized waste tire powder (WTP) and red pine wood waste flours (RPF) concentrations on the properties of pulverized-high density polyethylene (P-HDPE) composites were investigated. Ingredients were first mixed in a high-intensity mixer, later passed through single screw extruder to produce extrudates and finally pelletized and dried before sample manufacturing using injection molding machine. Contrary to the fact that lignocellulosic materials increase the brittleness of composites, the presence of WTP improved hardness and impact properties of lignocellulosic-based composite by making them softer. Both WTP and RPF concentrations have significantly increased density, thickness swelling (TSW) and water absorption of composites. Rising percentage of RPF improved the flexural strength, flexural modulus, tensile strength and tensile modulus values of composites. Addition of WTP, on the other hand, reduced these values. Although the presence of WTP has slightly increased the elongations at break (EatB) values in neat-HDPE, it decreased the EatB values of the composites having RPF in it. Thermal degradation started at 275 °C and 360 °C for RPF and WTP, respectively. With the loading of both fillers in the p-HDPE matrix, melting temperature of composites and crystallinity ratio of the polymer was slightly changed. SEM images showed improved dispersion of RPF due to MAPE usage. Through this study, some technological properties of injection molded P-HDPE based composites reinforced with WTP and RPF were determined and potential utilization of WTP in lignocellulosic-based composites was demonstrated.

Impact of UV-absorber and photo-sensitizer on the irradiated waste polyethylene hoses

Composite films of waste polyethylene (WPE) hoses containing carbon black (CB) as UV-stabilizer, and benzophenone (BP) as UV-absorber and photo-sensitizer were prepared. The effect of both CB and BP on the WPE hoses has been studied under the influence of thermal aging. Prepared composites before and after aging were subjected to gamma radiation at 50 kGy and characterized by determining the carbonyl index derived from FTIR, mechanical parameters, DSC, TGA, and SEM. Remarked improvement in the mechanical and thermal parameters were generally determined by the incorporation of CB and BP. Furthermore, melting temperature of composites after aging did not change with CB/BP loaded and reduces the effectiveness of the biodegradability of the films. The mechanism suggested that biodegradation rates were reduced with incorporation of both CB/BP and the composites become more resists to photo-degradation.

Improved thermal and mechanical properties of carbon fiber filled polyamide 46 composites

Abstract The thermal and mechanical properties of polyamide 46 (PA46) filled with carbon fiber (CF/PA46) composites were studied. CF/PA46 was fabricated by the method of melt blending and injection molding. The results showed that thermal conductivity, tensile strength and impact strength of the composite increased with the increase of weight fraction of CF, however, the elongation at the break decreased as its weight fraction increased. The addition of CF had little effect on the melting temperature of composites, while the crystallization onset (To) and crystallization peak (Tp) temperatures of composites shifted to higher points. The scanning electron microscope images showed that when the weight fraction of CF was increased, the CF was more likely to form thermal chains and a network. When the CF weight fraction was 40%, thermal conductivity was 1.49 W/(m·K), approximately 5.54 times as high as that of the pure PA46, and the thermal diffusivity was 0.9755 mm2/s, 6.5 times higher than that of the pure matrix. Comparing the experimental data with the three expected thermal conduction models data, the Maxwell-Eucken thermal conduction model was considered more suitable for the PA46/CF composite, in which the weight fraction of the filler was <10% in the thermal conductive system.

Electroconductive and Dielectric Properties of Composites Based on Bismuth Vanadate

J.N. Torba, N.V. Golubko, E.A. Fortalnova, G.M. Kaleva, M.G. Safronenko, N.U. Venskovskii and E.D. Politovaa,∗ Karpov Institute of Physical Chemistry, Vorontsovo Pole St., 10, 105064, Moscow, Russia Peoples’ Friendship University of Russia, Ordzhonikidze St., 3, 117198, Moscow, Russia Ceramic composites (100− n)Bi4V2O11−z–nCe0.9Gd0.1O1.9 with n = 0÷ 25 wt% were prepared and studied by the X-ray diffraction, dielectric spectroscopy, and impedance methods. Slight increase in the unit cell volume accompanied by monotonous decrease in temperatures and broadening of the α–β and β–γ phase transitions with increasing fluorite content was observed in the composites studied. Increase in melting temperatures of composites with n ≥ 10 with the retention of their high ionic conductivity was also proved.

The melting temperature–composition curves of poly(vinylidene fluoride)–poly(vinyl fluoride) mixtures and vinylidene fluoride–vinyl fluoride copolymers

The melting temperature–composition curves of poly(vinylidene fluoride)–poly(vinyl fluoride) mixtures and vinylidene fluoride–vinyl fluoride copolymers