scholarly journals Study on Physicochemical and Thermal Properties of Tetrabutylammonium-Based Cation Ionic Salts Induced by Al2O3 Additive for Thermal Energy Storage Application

Inorganics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 51
Author(s):  
Inge M. Sutjahja ◽  
Surjani Wonorahardjo ◽  
Surjamanto Wonorahardjo

The physicochemical and thermal properties of tetrabutylammonium bromide (TBA-Br) and tetrabutylammonium hexafluorophosphate (TBA-PF6), and their change with the addition of Al2O3, were investigated using infrared (IR) spectroscopy and by simultaneously conducting thermal thermogravimetric (TG) analysis and differential thermal analysis (DTA) to obtain the differential scanning calorimetry (DSC) thermogram. The change in the IR data is characterized by the growth of a large peak in the range of 3500 cm−1 and the reduction of peaks below 1000 cm−1 with the additive concentration. The decomposition temperature determined from the peak in the DTG curve is nearly constant for TBA-Br, and it decreases with the addition of Al2O3 for TBA-PF6, although it does not depend on the concentration of the additives. The DTA curve of ionic salts with the addition of Al2O3 shows additional peaks, which indicates a change in the sample’s temperature at disorder or phase transitions. The variation in the melting temperature with additive concentration is similar to that of decomposition temperature. The maximum heat of fusion value was approximately 67 kJ kg−1 for the doped TBA-Br and TBA-PF6 but was achieved at a different additive concentration. This is due to the additional disorder in the system induced by the dissolution of Al2O3.

Author(s):  
MK Gupta

The aim of the present study is to investigate the dynamic mechanical and thermal properties of hybrid jute/sisal fibre reinforced epoxy composites. The hybrid composites were prepared by hand layup technique having total fibre loading of 30% by weight with different weight ratios of jute and sisal fibres. Dynamic mechanical properties such as storage modulus ([Formula: see text]), loss modulus ([Formula: see text]) and damping ([Formula: see text]) were investigated in the temperature range of 30–200 ℃. The thermal stability of the prepared composites was studied using thermogravimetric analysis. Other thermal properties such as glass transition temperature ( Tg), crystallization temperature ( Tc) and decomposition temperature ( Td) were also obtained by differential scanning calorimetry. The results indicated a positive effect of hybridization in terms of increase in dynamic mechanical and thermal properties. Storage modulus, loss modulus and Tg were found to be higher for hybrid composite having a higher percentage of jute fibres.


2012 ◽  
Vol 535-537 ◽  
pp. 103-109 ◽  
Author(s):  
Xiang Min Xu ◽  
Li Ping Guo ◽  
Yu Dong Zhang ◽  
Zhi Jun Zhang

The polyoxymethylene-based composites containing reactable nano-SiO2were prepared in a twin-screw extruder by melt compounding, and mechanical and thermal properties of pure polyoxymethylene (POM) and composites were investigated. The results showed that reactable nano-SiO2could reinforce the tensile strength and Young’s modulus of composites. To the impact strength of composites, there was obvious improvement when a small amount of silica was added into POM. With the increase of silica content, the impact strength of composites showed a gradually decrease trend. It was worthy to note that reactable nano-SiO2could significantly increase the decomposition temperature of POM. When the content of reactaSubscript textble nano-SiO2was up to 5 wt%, the degradation temperature of composites could increase about 38.3°C under nSubscript textitrogen atmosphere and 43.8°C under air atmosphere, respectively, compared with pure POM. Furthermore, the differential scanning calorimetry (DSC) analysis showed that reactable nano-SiO2had a good heterogeneous nucleation capability in POM, and could increase crystallization temperature of POM, but surface structure of reactable nano-SiO2was not propitious to the growth of POM crystals, accordingly leading to the decreasing crystallinity of composites.


2021 ◽  
Vol 1028 ◽  
pp. 234-239
Author(s):  
Bambang Afrinaldi ◽  
David Natanael Vicarneltor ◽  
Reza Pahlevi Rudianto ◽  
Arif Rachman Hakim ◽  
Opa Fajar Muslim

Thermal properties, i.e. melting point and decomposition temperature of polymers, azodicarbonamide (ADC), and other additives mixture, are the most important information to determine the appropriate foaming process parameters. ADC has been widely used as a blowing agent for foam fabrication. Here, ADC will decompose and release gas which will be trapped in the melting polymer to make a foamed product. Originally, ADC has a decomposition temperature at around 220°C. In this study, the effect of Zinc Oxide (ZnO) addition on the thermal properties of intermediate product and Polyethylene/Ethylene Vinyl Acetate (PE/EVA) foam with ADC as the blowing agent was investigated. ZnO addition decreased the decomposition temperature of ADC. The thermal properties were characterized by Differential Scanning Calorimetry (DSC). The result showed that the decomposition temperature of ADC significantly decreased from the temperature of 220°C to 170°C with the increment of the ZnO.


2011 ◽  
Vol 221 ◽  
pp. 85-89 ◽  
Author(s):  
Wen Jian Deng ◽  
Xu Pin Zhuang ◽  
Ke Tian Guan ◽  
Bo Wen Cheng

To improve the thermal behavior of cellulose diacetate, cellulose diacetate-graft-poly(lactic acid) copolymers (CDA-g-PLAs) were synthesized by ring-opening polymerization of L-lactide using stannous octoate (Sn(Oct)2) as catalyst. The molecular structure of the copolymer was characterized by FT-IR and 1H-NMR and the thermal properties were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TG-DTA). The results showed that the product was grafted copolymer of cellulose diacetate-graft-poly(lactic acid) with different side-chain structure. The thermal processing properties of CDA-g-PLAs are remarkably improved with melting temperature(Tm) about 140°C which lower than that of CDA and decomposition temperature (Td) higher than 260°C.


Nanocellulose is a renewable and sustainable biomass product which could be derived from natural fibers for various applications. At present study, nanocrystalline cellulose (NCC) and cellulose nanowhisker (CNW) are extracted from roselle fiber through different combination of acid hydrolysis and ultrasonication processes. The thermal properties of both types nanocellulose are compared in order to study their different decomposition behavior towards high temperature. From thermogravimetric analysis (TGA) results, NCCs had significantly lower decomposition temperature than that of CNWs, particularly those extracted under mild condition of the combined processes. However, under harsh condition of the combined processes, the derivative thermogravimetric (DTG) curve revealed decrement in peak decomposition temperatures for both NCC and CNW products. This was in line with the sequential occurrence of endothermic and exothermic behaviors as presented in differential scanning calorimetry (DSC) curve analysis. Hence, as evaluated from the overall comparative results, CNW could be utilized as a promising reinforcing agent for composite materials fabrication.


2017 ◽  
Vol 31 (2) ◽  
pp. 246-264 ◽  
Author(s):  
JZ Liang ◽  
JZ Wang ◽  
Gary CP Tsui ◽  
CY Tang

The thermal properties and thermal stability of polypropylene (PP) composites separately filled with graphene nanoplatelets (GNPs) with three different sizes were measured using a differential scanning calorimetry and a thermal gravimetric analyser. The results showed that the values of the melting temperature of the composites were higher than that of the unfilled PP; the thermal stability increased with increasing the weight fraction and lateral dimension of GNPs in the case of low filler concentration, while the effect of the GNPs thickness on the thermal stability was insignificant; the onset decomposition temperature increased with increasing the GNPs lateral dimension, while the maximum thermal decomposition rate increased first and then decreased with increasing the GNPs weight fraction. The thermal stability improvement should be attributed to the sheet barrier function of the GNPs.


2013 ◽  
Vol 844 ◽  
pp. 330-333 ◽  
Author(s):  
Nosbi Norlin ◽  
Md Akil Hazizan

A hybrid compound of multiwalled carbon nanotubes-alumina (MWCNT-Al2O3) was successfully synthesized using chemical vapour deposition (CVD) method. MWCNT-Al2O3 at three different weight percent (0.5wt.%, 1.0wt.% and 1.5wt.%) was added into Silicone rubber of Polydimethylsiloxane (PDMS) using ultrasonic sonicator. Thermal analysis Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA) was performed on each composites and their thermal stability was compared. TGA thermogram showed that 1.0wt.% and 1.5wt% of hybrid compound had more weight loss recorded at decomposition temperature of 400°C. In addition, DSC thermogram also indicated that heat of fusion increased with increasing content (wt.%) of hybrid compound MWCNT-Al2O3 in the Polydimethylsiloxane composites. It was found that the presence of MWCNT-Al2O3 hybrid compound had changed the internal energy and the mass loss of the composite.


2020 ◽  
Vol 10 (3) ◽  
pp. 200-207
Author(s):  
Sabbir Ansari ◽  
Tasneem Fatma

Background: Poly-3-hydroxybutyrate (PHB) has attracted much consideration as biodegradable biocompatible polymer. This thermoplastic polymer has comparable material properties to polypropylene. Materials with more valuable properties may result from blending, a common practice in polymer science. Objective: In this paper, blends of PHB (extracted from cyanobacterium Nostoc muscorum NCCU- 442 with polyethylene glycol (PEG) were investigated for their thermal, tensile, hydrophilic and biodegradation properties. Methods: Blends were prepared in different proportions of PHB/PEG viz. 100/0, 98/2, 95/5, 90/10, 80/20, and 70/30 (wt %) using solvent casting technique. Morphological properties were investigated by using Scanning Electron Microscopy (SEM). Differential scanning calorimetry and thermogravimetric analysis were done for thermal properties determination whereas the mechanical and hydrophilic properties of the blends were studied by means of an automated material testing system and contact angle analyser respectively. Biodegradability potential of the blended films was tested as percent weight loss by mixed microbial culture within 60 days. Results: The blends showed good misciblity between PEG and PHB, however increasing concentrations of plasticizer caused morphological alteration as evidenced by SEM micrographs. PEG addition (10 % and above) showed significant alternations in the thermal properties of the blends. Increase in the PEG content increased the elongation at break ratio i.e enhanced the required plasticity of PHB. Rate of microbial facilitated degradation of the blends was greater with increasing PEG concentrations. Conclusion: Blending with PEG increased the crucial polymeric properties of cyanobacterial PHB.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2016
Author(s):  
Honghua Wang ◽  
Qilin Mei ◽  
Yujie Ding ◽  
Zhixiong Huang ◽  
Minxian Shi

Diallyl orthophthalate (DAOP) prepolymer was investigated as a reactive plasticizer to improve the processability of thermoplastics. The rheology of blends of DAOP prepolymer initiated by 2,3-dimethyl-2,3-diphenylbutane (DMDPB) and polyphenylene oxide (PPO) was monitored during the curing process, and their thermal properties and morphology in separated phases were also studied. Differential scanning calorimetry (DSC) results showed that the cure degree of the reactively plasticized DAOP prepolymer was reduced with increasing PPO due to the dilution effect. The increasing amount of the DAOP prepolymer led to a gradual decrease in the viscosity of the blends and the rheology behavior was consistent with the chemical gelation of DAOP prepolymer in blends. This indicated that the addition of the DAOP prepolymer effectively improved processability. The phase separation occurring during curing of the blend and the transition from the static to dynamic mode significantly influences the development of the morphology of the blend corresponding to limited evolution of the conversion around the gel point.


2019 ◽  
pp. 089270571987822
Author(s):  
Saud Aldajah ◽  
Mohammad Y Al-Haik ◽  
Waseem Siddique ◽  
Mohammad M Kabir ◽  
Yousef Haik

This study reveals the enhancement of mechanical and thermal properties of maleic anhydride-grafted polypropylene (PP- g-MA) with the addition of nanocrystalline cellulose (NCC). A nanocomposite was manufactured by blending various percentages of PP, MA, and NCC nanoparticles by means of a twin-screw extruder. The influence of varying the percentages of NCC on the mechanical and thermal behavior of the nanocomposite was studied by performing three-point bending, nanoindentation, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy tests. The novelty of this study stems on the NCC nanoparticles and their ability to enhance the mechanical and thermal properties of PP. Three-point bending and nanoindentation tests revealed improvement in the mechanical properties in terms of strength, modulus, and hardness of the PP- g-MA nanocomposites as the addition of NCC increased. SEM showed homogeneity between the mixtures which proved the presence of interfacial adhesion between the PP- g-MA incorporated with NCC nanoparticles that was confirmed by the FTIR results. DSC and TGA measurements showed that the thermal stability of the nanocomposites was not compromised due to the addition of the coupling agent and reinforced nanoparticles.


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