scholarly journals Исследование оптических, механических и термических свойств свободновисящих пленок на основе нанокомпозитных материалов MoSi-=SUB=-2-=/SUB=-N-=SUB=-x-=/SUB=- и ZrSi-=SUB=-2-=/SUB=-N-=SUB=-y-=/SUB=-

2019 ◽  
Vol 89 (11) ◽  
pp. 1680
Author(s):  
С.Ю. Зуев ◽  
А.Я. Лопатин ◽  
В.И. Лучин ◽  
Н.Н. Салащенко ◽  
Д.А. Татарский ◽  
...  

The optical, mechanical, and thermal properties of freestanding films based on nitrided molybdenum and zirconium disilicides were investigated. It has been shown that nitriding of silicides leads to a significant increase in the thermal stability of the films. So, if crystallization of initially amorphous freestanding MoSi2 or ZrSi2 films is observed at temperatures of 330-370°C, the introduction of nitrogen into the film makes it possible to increase the temperature up to 600-700°С at which MoSi2Nx and ZrSi2Ny (at least for x ≥ 0.25, y ≥ 1.3) films can be used for many hours when heated under vacuum. The study of mechanical tensile strength showed that the ultimate strength is weakly dependent on the nitrogen content in MoSi2Nx films (0 ≤ x ≤ 0.55). Comparison of the properties of MoSi2Nx and ZrSi2Ny films obtained by the magnetron method at the same nitrogen partial pressure demonstrated that at similar values of the transmittance at 13.5 nm, nitrated ZrSi2 films are more effective as protective coatings (less susceptible to oxidation and more resistant to degradation at high temperatures).

2019 ◽  
Vol 972 ◽  
pp. 172-177
Author(s):  
Sirirat Wacharawichanant ◽  
Patteera Opasakornwong ◽  
Ratchadakorn Poohoi ◽  
Manop Phankokkruad

This work studied the effects of various types of cellulose fibers on the morphology, mechanical and thermal properties of poly(lactic acid) (PLA)/propylene-ethylene copolymer (PEC) (90/10 w/w) blends. The PLA/PEC blends before and after adding cellulose fibers were prepared by melt blending method in the internal mixer and molded by compression method. The morphological analysis observed that the presence of cellulose in PLA did not change the phase morphology of PLA, and PLA/cellulose composite surfaces were observed the cellulose fibers inserted in PLA matrix and fiber pull-out. The phase morphology of PLA/PEC blends was changed from brittle fracture to ductile fracture behavior and showed the phase separation between PLA and PEC phases. The presence of celluloses did not improve the compatibility between PLA and PEC phases. The tensile stress and strain curves found that the tensile stress of PLA was the highest value. The addition of all celluloses increased Young’s modulus of PLA. The PEC presence increased the tensile strain of PLA over two times when compared with neat PLA and PLA was toughened by PEC. The incorporation of cellulose fibers in PLA/PEC blends could improve Young’s modulus, tensile strength, and stress at break of the blends. The thermal stability showed that the degradation temperatures of all types of cellulose were less than the degradation temperatures of PLA. Thus, the incorporation of cellulose in PLA could not enhance the thermal stability of PLA composites and PLA/PEC composites. The degradation temperature of PEC was the highest value, but it could not improve the thermal stability of PLA. The incorporation of cellulose fibers had no effect on the melting temperature of the PLA blend and composites.


e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Deng Xu ◽  
V. Sridhar ◽  
Thanh Tu Pham ◽  
Jin Kuk Kim

AbstractThe potential of exfoliated graphite nano platelets (xGnP™) as reinforcing fillers in flouroelastomer has been investigated. The dispersion of the nano graphite platelets in the polymer matrix has been investigated by WAXD, SEM, TEM, EPMA and AFM. WAXD studies indicated that the processing of composites did not change the inter-gallery distance (d-spacing) of the graphite platelets. The effect of increasing nano graphite loadings on mechanical properties like tensile strength, modulus and tear resistance has been studied. Formation of weld lines on the fracture surface of the composite has been observed by SEM. The thermal stability was determined using thermogravimetric analysis. The composites showed higher thermal stability in comparison with nonreinforced polymer.


Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1557 ◽  
Author(s):  
Khaliq Majeed ◽  
Ashfaq Ahmed ◽  
Muhammad Saifullah Abu Bakar ◽  
Teuku Meurah Indra Mahlia ◽  
Naheed Saba ◽  
...  

In recent years, there has been considerable interest in the use of natural fibers as potential reinforcing fillers in polymer composites despite their hydrophilicity, which limits their widespread commercial application. The present study explored the fabrication of nanocomposites by melt mixing, using an internal mixer followed by a compression molding technique, and incorporating rice husk (RH) as a renewable natural filler, montmorillonite (MMT) nanoclay as water-resistant reinforcing nanoparticles, and polypropylene-grafted maleic anhydride (PP-g-MAH) as a compatibilizing agent. To correlate the effect of MMT delamination and MMT/RH dispersion in the composites, the mechanical and thermal properties of the composites were studied. XRD analysis revealed delamination of MMT platelets due to an increase in their interlayer spacing, and SEM micrographs indicated improved dispersion of the filler(s) from the use of compatibilizers. The mechanical properties were improved by the incorporation of MMT into the PP/RH system and the reinforcing effect was remarkable as a result of the use of compatibilizing agent. Prolonged water exposure of the prepared samples decreased their tensile and flexural properties. Interestingly, the maximum decrease was observed for PP/RH composites and the minimum was for MMT-reinforced and PP-g-MAH-compatibilized PP/RH composites. DSC results revealed an increase in crystallinity with the addition of filler(s), while the melting and crystallization temperatures remained unaltered. TGA revealed that MMT addition and its delamination in the composite systems improved the thermal stability of the developed nanocomposites. Overall, we conclude that MMT nanoclay is an effective water-resistant reinforcing nanoparticle that enhances the durability, mechanical properties, and thermal stability of composites.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 728
Author(s):  
Sangyoon Park ◽  
Sarinthip Thanakkasaranee ◽  
Hojun Shin ◽  
Youngsoo Lee ◽  
Guman Tak ◽  
...  

To improve the dimensional thermal stability of polyethylene terephthalate (PET), a poly(ethylene glycol 1,4-cyclohexane dimethylene (CHDM) isosorbide (ISB) terephthalate) (PEICT) known as ECOZEN®T110 (EZT) was introduced into PET using a melt blending technique. The miscibility, morphology, and thermal properties of the PET/EZT samples were investigated. The introduction of amorphous EZT into semi-crystalline PET increased the glass transition temperature (Tg) but decreased the crystallinity, which could be related to the transesterification reaction. By adding EZT contents up to 20%, the PET/EZT samples showed a single Tg, which indicated the miscibility between PET and EZT. However, two Tg values were observed in the PET/EZT samples with higher EZT contents (30–70%), indicating partial miscibility. This may have been due to the slightly different rheological and thermodynamic parameters that were affected by a higher ratio of bulky (rigid ISB and ductile CHDM) groups in EZT. However, the heat distortion temperature of the PET/EZT samples remarkably increased, which indicated that the dimensional stability was truly enhanced. Although the crystallinity of the PET/EZT samples decreased with increasing EZT content, the tensile strength and Young’s modulus decreased slightly. Based on these results, the as-prepared PET/EZT samples with high dimensional stability can be used as a high-temperature polymeric material in various applications.


2018 ◽  
Vol 280 ◽  
pp. 264-269
Author(s):  
Heng Chun Wei ◽  
Teh Pei Leng ◽  
Yeoh Chow Keat

This work reports on mechanical and thermal properties of a novel polymer blend. Blends were prepared by mixing silicone rubber with diphenyl – 4,4 – dissocyanate in different ratios. Graphene nanoplatelets was added as conductive filler to improve the electrical conductivity of the blends. The mechanical properties, including tensile and tear performances were measured by a material testing system. The thermal stability of the blends was measured by thermogravimetric analysis. Incorporation 20 vol.% of silicone rubber can help to improve the thermal stability of the blend, meanwhile optimum mechanical properties of the blends is achieved.


2015 ◽  
Vol 37 ◽  
pp. 15 ◽  
Author(s):  
Azin Paydayesh ◽  
Ahmad Aref Azar ◽  
Azam Jalali Arani

In this work, Poly Lactic Acid/Poly methyl Methacrylate (PLA/PMMA) blends in various compositions prepared and morphology and properties of these blends was investigated. Moreover, the effect of adding different amounts of Graphene Nanoplatelets (GNP) on the morphology of the blends (by SEM), the interaction of nanopalates with polymer phases (by FTIR) and its effect on the mechanical properties and thermal stability of the samples were examined. The results of the study showed that in different amounts of graphene, these plates were preferentially located in the polymer phases dissimilarly and thus, caused the change of the blend morphology. In addition, measuring the mechanical properties by tensile test and results of thermal analysis by TGA indicated the improvement of thermal stability, modulus and mechanical strength and reduction of the elongation at break of graphene containing blends with increasing the loading of GNP. The changing behavior of the mechanical and thermal properties was proportional to the Graphene localization in blend phases.


2020 ◽  
Vol 1010 ◽  
pp. 124-129 ◽  
Author(s):  
Haziq Amri Mohd ◽  
Mohamad Bashree Abu Bakar ◽  
Mohamad Najmi Masri ◽  
Muhammad Azwadi Sulaiman ◽  
Mohd Hazim Mohamad Amini ◽  
...  

In this study, kenaf fibre mat (NWKFM)-graphene nanoplatelets (GNP) reinforced polypropylene (PP) composites were fabricated by using compression moulding. The hybridization was done to enhance the mechanical and thermal properties by adding different amount of graphene nanoplatelets as filler in the biocomposite samples. Pure PP and nanocomposite samples of PP+GNP were also fabricated. Maleic anhydride grafted polypropylene (MAPP) was used as a coupling agent to increase the interfacial adhesion of matrix and reinforcement of the biocomposites and hybrid composites samples. The chemical composition and constituent changes were studied by using Fourier transform infrared spectroscopy (FTIR) analysis. The mechanical properties in term of flexural and tensile were tested using a universal testing machine (UTM). Thermogravimetric analysis (TGA) was carried out to determine the thermal stability of the composite’s samples. Overall, the results show that the stiffness properties (young’s and tensile modulus) of pure PP and biocomposites enhanced with addition of GNP. The flexural strength also shows promising result with the inclusion of GNP. However, the tensile strength shows a reduction with the addition of GNP. The TGA results reveal that the addition of GNP increases the thermal stability of pure PP and the biocomposites based on the comparison of Tonset values.


2019 ◽  
Vol 953 ◽  
pp. 47-52
Author(s):  
Sirirat Wacharawichanant ◽  
Attachai Sriwattana ◽  
Kulaya Yaisoon ◽  
Manop Phankokkruad

The effects of the montmorillonite clay surface modified with 0.5-5 wt% aminopropyltriethoxysilane and 15-35% octadecylamine (Clay-APTSO) on morphology, mechanical and thermal properties of poly(lactic acid) (PLA)/ethylene-octene copolymer (EOC)/Clay-APTSO composites were investigated. The blends of PLA/EOC with and without Clay-APTSO were prepared by melt mixing in an internal mixer. Scanning electron microscopy analysis observed the morphology of PLA/EOC blends demonstrated a phase separation of minor phase and matrix phase. The addition of Clay-APTSO in PLA/EOC blends showed significant decreased in droplet size of dispersed EOC phase, thus, Clay-APTSO acted as an effective compatibilizer in the PLA/EOC blends. The results of tensile properties found the decrease of Young’s modulus of PLA when added EOC due to the low modulus and flexibility of EOC. While the incorporation of Clay-APTSO increased significantly Young’s modulus of PLA/EOC blends at low EOC and Clay-APTSO content. The strain at break of the blends increased with the increase of EOC loading, this indicated the presence of EOC enhanced the elongation at break of PLA, while the addition Clay-APTSO reduced the strain at break of PLA/EOC blends. The tensile strength of all blend compositions improved when added Clay-APTSO and the tensile strength showed the highest value at 3 phr of Clay-APTSO. The thermal stability of PLA/EOC blends did not change when compared with neat PLA, and when added Clay-APTSO in the blends could improve the thermal stability of the PLA/EOC blends.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3924 ◽  
Author(s):  
Mohammad A. Al-Saleh ◽  
Abdirahman A. Yussuf ◽  
Salah Al-Enezi ◽  
Roaya Kazemi ◽  
Mat Uzir Wahit ◽  
...  

In this research work, graphene nanoplatelets (GNP) were selected as alternative reinforcing nanofillers to enhance the properties of polypropylene (PP) using different compatibilizers called polypropylene grafted maleic anhydride (PP-g-MA) and ethylene-octene elastomer grafted maleic anhydride (POE-g-MA). A twin screw extruder was used to compound PP, GNP, and either the PP-g-MA or POE-g-MA compatibilizer. The effect of GNP loading on mechanical and thermal properties of neat PP was investigated. Furthermore, the influence and performance of different compatibilizers on the final properties, such as mechanical and thermal, were discussed and reported. Tensile, flexural, impact, melting temperature, crystallization temperature, and thermal stability were evaluated by using a universal testing system, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). For mechanical properties, it was found that increasing GNP content from 1 wt.% to 5 wt.% increased tensile strength of the neat PP up to 4 MPa. The influence of compatibilizers on the mechanical properties had been discussed and reported. For instance, the addition of PP-g-MA compatibilizer improved tensile strength of neat PP with GNP loading. However, the addition of compatibilizer POE-g-MA slightly decreased the tensile strength of neat PP. A similar trend of behavior was observed for flexural strength. For thermal properties, it was found that both GNP loading and compatibilizers have no significant influence on both crystallization and melting temperature of neat PP. For thermal stability, however, it was found that increasing the GNP loading had a significant influence on improving the thermal behavior of neat PP. Furthermore, the addition of compatibilizers into the PP/GNP nanocomposite had slightly improved the thermal stability of neat PP.


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