Evaluation of thermo-mechanical, dielectric and corrosion resistant properties of cardanol benzoxazine-epoxy based hybrid composites: A very low temperature curing pre-polymer for high performance paint related applications

2019 ◽  
Vol 32 (5) ◽  
pp. 524-539 ◽  
Author(s):  
V Selvaraj ◽  
TR Raghavarshini ◽  
M Alagar
Keyword(s):  
Thermal Stability ◽  
Low Temperature ◽  
High Performance ◽  
Hybrid Composites ◽  
Industrial Applications ◽  
Curing Temperature ◽  
Polymerization Temperature ◽  
Corrosion Resistant ◽  
The Matrix ◽  
Ep Matrix

In the present work, the hybrid siloxane-based cardanol-benzoxazine-epoxy (1:1 ratio) matrix (SBCBz-EP) capable of curing at substantially low temperature when compared with that of conventional benzoxazines was prepared and characterized. The matrix SBCBz-EP was reinforced with varying weight percentages (1, 3 and 5 wt%) of hydroxyl-terminated cyclotriphosphazene (HTCP) and the resulting hybrid composites were characterized by modern analytical methods, which can be used for paint-related applications due to their low-temperature curing behaviour. Data obtained from differential scanning calorimeter analysis infer that the glass transition temperature of the hybrid matrix (SBCBz-EP) and HTCP reinforced with 1, 3 and 5 wt% composites was 73°C, 75°C, 82°C, and 88°C, respectively. The polymerization temperature obtained for SBCBz-EP matrix and HTCP-reinforced hybrid composites was considerably lower than that of conventional benzoxazines. The present hybridization approach of benzoxazine and epoxy paves an avenue to alleviate the deficient characteristics of both industrially valuable resins namely high curing temperature and brittle behaviour of benzoxazines and also to improve thermal stability, mechanical strength and flame-retardant behaviour of epoxy resins. Data obtained from mechanical, dielectric, thermal stability and corrosion-resistant studies indicate that the properties of hybrid composites (HTCP/SBCBZ-EP) were enhanced to an appreciable extent according to the wt% of HTCP and it can be suggested that these hybrid composite materials can be used in the form of adhesives, sealants, encapsulants and water-resistant coatings for high performance industrial applications.

scholarly journals Curing Kinetics and Thermal Stability of Epoxy Composites Containing Newly Obtained Nano-Scale Aluminum Hypophosphite (AlPO2)

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 644 ◽  
Author(s):  
Farimah Tikhani ◽  
Shahab Moghari ◽  
Maryam Jouyandeh ◽  
Fouad Laoutid ◽  
Henri Vahabi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
High Performance ◽  
Frequency Factor ◽  
Curing Temperature ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Nano Scale ◽  
Aluminum Hypophosphite ◽  
Thermal Stability Of

For the first time, nano-scale aluminum hypophosphite (AlPO2) was simply obtained in a two-step milling process and applied in preparation of epoxy nanocomposites varying concentration (0.1, 0.3, and 0.5 wt.% based on resin weight). Studying the cure kinetics and thermal stability of these nanocomposites would pave the way toward the design of high-performance nanocomposites for special applications. Scanning electron microscopy (SEM) and transmittance electron microscopy (TEM) revealed AlPO2 particles having domains less than 60 nm with high potential for agglomeration. Excellent (at heating rate of 5 °C/min) and Good (at heating rates of 10, 15 and 20 °C/min) cure states were detected for nanocomposites under nonisothermal differential scanning calorimetry (DSC). While the dimensionless curing temperature interval (ΔT*) was almost equal for epoxy/AlPO2 nanocomposites, dimensionless heat release (ΔH*) changed by densification of polymeric network. Quantitative cure analysis based on isoconversional Friedman and Kissinger methods gave rise to the kinetic parameters such as activation energy and the order of reaction as well as frequency factor. Variation of glass transition temperature (Tg) was monitored to explain the molecular interaction in the system, where Tg increased from 73.2 °C for neat epoxy to just 79.5 °C for the system containing 0.1 wt.% AlPO2. Moreover, thermogravimetric analysis (TGA) showed that nanocomposites were thermally stable.

scholarly journals High efficiency Mg2(Si,Sn)-based thermoelectric materials: scale-up synthesis, functional homogeneity, and thermal stability

RSC Advances ◽  
2019 ◽  
Vol 9 (40) ◽  
pp. 23021-23028 ◽  
Author(s):  
Nader Farahi ◽  
Christian Stiewe ◽  
D. Y. Nhi Truong ◽  
Johannes de Boor ◽  
Eckhard Müller
Keyword(s):  
Thermal Stability ◽  
Thermoelectric Materials ◽  
High Performance ◽  
High Efficiency ◽  
Scale Up ◽  
Synthesis Method ◽  
Industrial Applications ◽  
Magnesium Silicide ◽  
Functional Homogeneity ◽  
Scalable Synthesis

Considering the need for large quantities of high efficiency thermoelectric materials for industrial applications, a scalable synthesis method for high performance magnesium silicide based materials is proposed.

A high-performance SDC-infiltrated nanoporous silver cathode with superior thermal stability for low temperature solid oxide fuel cells

2018 ◽  
Vol 6 (17) ◽  
pp. 7357-7363 ◽  
Author(s):  
Tsung-Han Lee ◽  
Liangdong Fan ◽  
Chen-Chiang Yu ◽  
Florencia Edith Wiria ◽  
Pei-Chen Su
Keyword(s):  
Thermal Stability ◽  
Fuel Cells ◽  
Low Temperature ◽  
Electrochemical Performance ◽  
Solid Oxide Fuel Cells ◽  
High Performance ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Infiltration Method ◽  
Silver Cathode

A simple and effective infiltration method is demonstrated to improve the thermal stability and electrochemical performance of a nanoporous silver cathode.

scholarly journals Understanding the Origin of the Hysteresis of High-Performance Solution Processed Polycrystalline SnO2 Thin-Film Transistors and Applications to Circuits

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Christophe Avis ◽  
Jin Jang
Keyword(s):  
Thin Film ◽  
Tin Oxide ◽  
Thin Film Transistors ◽  
High Performance ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Curing Temperature ◽  
Sno2 Thin Film ◽  
Large Area ◽  
Solution Processed

Crystalline tin oxide has been investigated for industrial applications since the 1970s. Recently, the amorphous phase of tin oxide has been used in thin film transistors (TFTs) and has demonstrated high performance. For large area electronics, TFTs are well suited, but they are subject to various instabilities due to operating conditions, such as positive or negative bias stress PBS (NBS). Another instability is hysteresis, which can be detrimental in operating circuits. Understanding its origin can help fabricating more reliable TFTs. Here, we report an investigation on the origin of the hysteresis of solution-processed polycrystalline SnO2 TFTs. We examined the effect of the carrier concentration in the SnO2 channel region on the hysteresis by varying the curing temperature of the thin film from 200 to 350 °C. Stressing the TFTs characterized further the origin of the hysteresis, and holes trapped in the dielectric are understood to be the main source of the hysteresis. With TFTs showing the smallest hysteresis, we could fabricate inverters and ring oscillators.

scholarly journals Fabrication of High-Performance Bamboo–Plastic Composites Reinforced by Natural Halloysite Nanotubes

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2259
Author(s):  
Xiaobei Jin ◽  
Jingpeng Li ◽  
Rong Zhang ◽  
Zehui Jiang ◽  
Daochun Qin
Keyword(s):  
Thermal Stability ◽  
High Performance ◽  
Moisture Absorption ◽  
Mechanical Performance ◽  
Halloysite Nanotubes ◽  
Industrial Applications ◽  
High Concentration ◽  
Morphological Studies ◽  
Plastic Composites ◽  
The Impact

Bamboo-plastic composites (BPCs) as new biomass-plastic composites have recently attracted much attention. However, weak mechanical performance and high moisture absorption as well as low thermal stability greatly limit their industrial applications. In this context, different amounts of halloysite nanotubes (HNTs) were used as a natural reinforcing filler for BPCs. It was found that the thermal stability of BPCs increased with increasing HNT contents. The mechanical strength of BPCs was improved with the increase in HNT loading up to 4 wt% and then worsened, while the impact strengths were slightly reduced. Low HNT content (below 4 wt%) also improved the dynamic thermomechanical properties and reduced the water absorption of the BPCs. Morphological studies confirmed the improved interfacial compatibility of the BPC matrix with 4 wt% HNT loading, and high-concentration HNT loading (above 6 wt%) resulted in easy agglomeration. The results highlight that HNTs could be a feasible candidate as nanoreinforcements for the development of high-performance BPCs.

scholarly journals Thermal and Flammability Properties of Kenaf/Recycled Carbon Filled with Cardanol Hybrid Composites

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Zahra Dashtizadeh ◽  
K. Abdan ◽  
M. Jawaid ◽  
Masoud Dashtizadeh
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Flame Retardancy ◽  
Hybrid Composites ◽  
Cashew Nut Shell Liquid ◽  
Fiber Loading ◽  
Cashew Nut ◽  
The Matrix ◽  
Cashew Nut Shell ◽  
Thermal Stability Of

In this paper, hybrid composites were fabricated by using kenaf and recycled carbon with a cashew nut shell liquid (CNSL) derivative known as cardanol as the matrix by a compression molding technique. In this work, we look for the effect of recycled carbon weight loading (15%, 25%, and 35%) on the thermal properties of kenaf/cardanol composites while maintaining the total fiber loading of 50 wt%. TGA, DSC, DMA, and flammability UL 90 HB properties of the specimens were studied. The results indicate that cardanol improved the thermal stability of kenaf and hybridization with recycled carbon also further improved the thermal stability of the specimens. The flammability UL 90 HB test determines the flame retardancy property of all specimens.

Exceptional low-temperature activity of perovskite-type AlCeO3 solid solution supported Ni-based nanocatalyst towards CO2 methanation

2021 ◽  
Author(s):  
Jingyi Zhang ◽  
Baojin Ren ◽  
Guoli Fan ◽  
Lan Yang ◽  
Feng Li
Keyword(s):  
Solid Solution ◽  
Renewable Energy ◽  
Low Temperature ◽  
Noble Metal ◽  
High Performance ◽  
Industrial Applications ◽  
Co2 Methanation ◽  
Noble Metal Catalysts ◽  
Supported Ni ◽  
Perovskite Type

Currently, developing high-performance and stable non-noble metal catalysts for low temperature CO2 methanation is a quite challenge for practical industrial applications in the terms of highly efficient and renewable energy...

scholarly journals Catalytic Polymerization of Phthalonitrile Resins by Carborane with Enhanced Thermal Oxidation Resistance: Experimental and Molecular Simulation

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 219
Author(s):  
Yuxiang Jia ◽  
Xiaojun Bu ◽  
Junyu Dong ◽  
Quan Zhou ◽  
Min Liu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Oxidation Resistance ◽  
High Performance ◽  
Steric Structure ◽  
Theoretical Models ◽  
Curing Temperature ◽  
Polymerization Process ◽  
National Defense ◽  
Oxidative Resistance ◽  
Markovnikov Addition

Biphenyl phthalonitrile (BPh) resins with good thermal and thermo-oxidative stability demonstrate great application potential in aerospace and national defense industries. However, BPh monomer has a high melting point, poor solubility, slow curing speed and high curing temperature. It is difficult to control the polymerization process to obtain the resins with high performance. Here, a BPh prepolymer (BPh-Q) was prepared by reacting 1,7-bis(hydroxymethyl)-m-carborane (QCB) with BPh monomers. The BPh-Q exhibited much better solubility, faster curing speed and lower curing temperature compared with pure BPh and BPh modified with bisphenol A (BPh-B, a common prepolymer of BPh). Thus, the polymerization process of BPh was greatly accelerated at a low temperature, resulting in a BPh resin with enhanced thermostability and oxidation resistance. The experimental and theoretical models revealed the promotion effect of B-H bond on the curing reaction of phthalonitrile via Markovnikov addition reaction due to the special steric structure of carborane. This study provided an efficient method to obtain low-temperature curing phthalonitrile resins with high thermal and thermo-oxidative resistance, which would be potentially useful for the preparation of high-performance cyanide resin-based composites.

Morphology of High-Performance Rigid-Rod Polymer Fibers and Molecular Composites

1989 ◽  
Vol 47 ◽  
pp. 338-339
Author(s):  
W.W. Adams ◽  
S. J. Krause
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Liquid Crystalline ◽  
Molecular Level ◽  
Synergistic Effects ◽  
Tensile Modulus ◽  
Commercial Development ◽  
The Matrix ◽  
Molecular Composites ◽  
Rigid Rod

Rigid-rod polymers such as PBO, poly(paraphenylene benzobisoxazole), Figure 1a, are now in commercial development for use as high-performance fibers and for reinforcement at the molecular level in molecular composites. Spinning of liquid crystalline polyphosphoric acid solutions of PBO, followed by washing, drying, and tension heat treatment produces fibers which have the following properties: density of 1.59 g/cm3; tensile strength of 820 kpsi; tensile modulus of 52 Mpsi; compressive strength of 50 kpsi; they are electrically insulating; they do not absorb moisture; and they are insensitive to radiation, including ultraviolet. Since the chain modulus of PBO is estimated to be 730 GPa, the high stiffness also affords the opportunity to reinforce a flexible coil polymer at the molecular level, in analogy to a chopped fiber reinforced composite. The objectives of the molecular composite concept are to eliminate the thermal expansion coefficient mismatch between the fiber and the matrix, as occurs in conventional composites, to eliminate the interface between the fiber and the matrix, and, hopefully, to obtain synergistic effects from the exceptional stiffness of the rigid-rod molecule. These expectations have been confirmed in the case of blending rigid-rod PBZT, poly(paraphenylene benzobisthiazole), Figure 1b, with stiff-chain ABPBI, poly 2,5(6) benzimidazole, Fig. 1c A film with 30% PBZT/70% ABPBI had tensile strength 190 kpsi and tensile modulus of 13 Mpsi when solution spun from a 3% methane sulfonic acid solution into a film. The modulus, as predicted by rule of mixtures, for a film with this composition and with planar isotropic orientation, should be 16 Mpsi. The experimental value is 80% of the theoretical value indicating that the concept of a molecular composite is valid.

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