Synthesis of Carbon Nanotubes, and the Effect on Thermal Stability in High-Impact Polystyrene

2008 ◽  
Vol 61 (1) ◽  
pp. 72 ◽  
Author(s):  
Qinghong Kong ◽  
Junhao Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Degradation Mechanism ◽  
High Impact ◽  
Gas Chromatography Mass Spectrometry ◽  
Scanning Calorimetry ◽  
Pyrolysis Gas ◽  
High Impact Polystyrene ◽  
Synthesis Of Carbon Nanotubes ◽  
Better Than

Carbon nanotubes (CNTs) with diameters ranging from 40 to 100 nm have been synthesized by the solvothermal process using ethanol as a carbon source and LaNiO3 as catalyst. The synthesized CNTs can be used for filaments in high-impact polystyrene (HIPS). HIPS/CNT nanocomposites have been prepared by the melt–intercalation process. Thermogravimetric analysis and differential scanning calorimetry indicate that the thermal stability of HIPS/CNT nanocomposites is better than that of HIPS. The thermal degradation mechanism was investigated by pyrolysis gas chromatography mass spectrometry.

Thermal and Dynamic Mechanical Behaviours of CCTO/ENR-25 Composite

2020 ◽  
Vol 1010 ◽  
pp. 274-279
Author(s):  
Syifa' Muhamad Sharifuddin ◽  
Mohd Shukri Mat Nor ◽  
Fathin Asila Mohd Pabli ◽  
Piyawadee Luangchuang ◽  
Wannarat Chueangchayaphan ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Storage Modulus ◽  
Electronic Device ◽  
Filler Content ◽  
Degradation Mechanism ◽  
Compression Moulding ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Significant Difference ◽  
High Storage

A study on polymer-ceramic composite, CaCu3Ti4O12 (CCTO) embedded in epoxidised natural rubber (ENR-25) were successfully fabricated through mixing method using an internal mixer and two-roll mill followed by hot-pressed via compression moulding for a potential electronic device such as a flexible capacitor. CCTO powders were successfully synthesised through a solid-state reaction and calcined at 900 °C for 12 hours. The ENR-25 was blended with 0, 20, 40, 60, 80, 100, and 120 phr (part per hundreds of rubber) of CCTO powders. Thermal stability and degradation are crucial properties for the composite based polymer. Therefore, thermogravimetric and differential scanning calorimetry (TGA/DSC) used to find out the thermal reaction and degradation mechanism of CCTO/ENR-25 composites. Besides, dynamic mechanical analysis (DMA) also used to investigate glass transition temperature (Tg) and storage modulus. TGA/DSC showed a two-step degradation mechanism with increasing thermal stability over increasing filler content of CCTO and only showed a major endothermic reaction. However, for DMA there is no significant difference in Tg value between each composite but showed high storage modulus up to 4398 MPa for 120 phr. High storage modulus indicates the high stiffness of the composite. In conclusion, the addition of filler content will show high thermal stability, storage modulus, and stiffness of CCTO/ENR-25 composites.

INFLUENCE OF NANOFILLER ON THERMAL DEGRADATION RESISTANCE OF HYDROGENATED NITRILE BUTADIENE RUBBER

2018 ◽  
Vol 92 (2) ◽  
pp. 263-285 ◽  
Author(s):  
Tuhin Saha ◽  
Anil K. Bhowmick
Keyword(s):  
Atomistic Simulation ◽  
Model Compound ◽  
Degradation Mechanism ◽  
Decomposition Temperature ◽  
Industrial Applications ◽  
Gas Chromatography Mass Spectrometry ◽  
Butadiene Rubber ◽  
Pyrolysis Gas ◽  
Initial Decomposition Temperature ◽  
Acrylonitrile Butadiene Rubber

ABSTRACT Studies on the degradation of elastomers and their prevention have become increasingly important in recent years because of stringent environmental conditions in many industrial applications. The reactive atomistic simulation was executed on a hydrogenated acrylonitrile-butadiene rubber (HNBR40) model compound composed of 40 monomer units. The reactive simulation was used to study the decomposition behavior of HNBR40, to visualize different pyrolysis products, and also to analyze the degradation mechanism of HNBR40. Ethylene, propylene, and acrylonitrile were observed as dominant products at lower temperature, and 1-butene was found at higher temperature. Pyrolysis–gas chromatography–mass spectrometry was used to verify the decomposition products obtained from the prediction of atomistic simulation. In this study, nanofillers, especially nanoclays and nanosilicas, were used to prevent degradation significantly. Restricted degradation by the nanofiller-reinforced rubber prolonged the durability. Furthermore, the reactive simulation was performed to understand thermal decomposition characteristics of the model compound in the presence of the nanofiller. The initial decomposition temperature, the final degradation temperature, and the rate of degradation improved to a great extent on the addition of the model nanosilica compound as obtained from the simulation studies. Moreover, the lifetime of nanoclay- and nanosilica-reinforced hydrogenated acrylonitrile–butadiene rubber was calculated by using thermogravimetric analysis, and its useful lifetime was compared with that of the pristine polymer in the application temperature range of 150 °C.

scholarly journals Examining the Influence of Re–Used Nanofiller—Pyrolyzed Montmorillonite, on the Thermal Properties of Polypropylene–Based Engineering Nanocomposites

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2636
Author(s):  
Tomasz M. Majka ◽  
Oskar Bartyzel ◽  
Konstantinos N. Raftopoulos ◽  
Joanna Pagacz ◽  
Krzysztof Pielichowski
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Thermogravimetric Analysis ◽  
Control Sample ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Stabilization Effect ◽  
Polypropylene Melt ◽  
Better Than

Pyrolysis of the polypropylene/montmorillonite (PP/OMMT) nanocomposites allows for recovery of the filler that can be then re–used to produce PP/pyrolyzed MMT (PMMT) nanostructured composites. In this work, we discuss the thermal properties of PP/PMMT composites investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It has been found that effect of PMMT (5 wt. % and 10 wt. %) on matrix thermal stability occurs at temperatures above 300 °C. Addition of 5 wt. % and 10 wt. % of PMMT into polypropylene system gave good stabilization effect, as confirmed by the overall stabilization effect (OSE) values, which increased by 4% and 7%, respectively, compared to the control sample (PP). Interestingly, the presence of 1 wt. % and 3 wt. % of pyrolyzed clay stabilizes the system better than the same concentrations of organoclay added into polypropylene melt. DSC data revealed that pyrolyzed clay has still the same tendency as organoclay to enhance formation of the α and β crystalline PP phases only. The pyrolyzed MMT causes an improvement of the modulus in the glassy as well as rubbery regions, as confirmed by DMA results.

scholarly journals Improved Weathering Performance of Poly(Lactic Acid) through Carbon Nanotubes Addition: Thermal, Microstructural, and Nanomechanical Analyses

Biomimetics ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 61
Author(s):  
Thevu Vu ◽  
Peyman Nikaeen ◽  
William Chirdon ◽  
Ahmed Khattab ◽  
Dilip Depan
Keyword(s):  
Carbon Nanotubes ◽  
Lactic Acid ◽  
Uv Light ◽  
Degradation Mechanism ◽  
Decomposition Temperature ◽  
Poly Lactic Acid ◽  
Accelerated Weathering ◽  
Degradation Behavior ◽  
Scanning Calorimetry ◽  
Norrish Type

To understand the interrelationship between the microstructure and degradation behavior of poly(lactic acid) (PLA), single-walled carbon nanotubes (CNTs) were introduced into PLA as nucleating agents. The degradation behavior of PLA-CNT nanocomposites was examined under accelerated weathering conditions with exposure to UV light, heat, and moisture. The degradation mechanism proceeded via the Norrish type II mechanism of carbonyl polyester. Differential scanning calorimetry (DSC) studies showed an increase in glass transition temperature, melting temperature, and crystallinity as a result of the degradation. However, pure PLA showed higher degradation as evidenced by increased crystallinity, lower onset decomposition temperature, embrittlement, and a higher number of micro-voids which became broader and deeper during degradation. In the PLA-CNT nanocomposites, CNTs created a tortuous pathway which inhibits the penetration of water molecules deeper into the polymer matrix, making PLA thermally stable by increasing the initial temperature of mass loss. CNTs appear to retard PLA degradation by impeding mass transfer. Our study will facilitate designing environmentally friendly packaging materials that display greater resistance to degradation in the presence of moisture and UV light.

PP/MWCNTs composites: Effects of length of MWCNTs on isothermal crystallization behaviors, crystalline structure, and thermal stability

2017 ◽  
Vol 52 (4) ◽  
pp. 503-517 ◽  
Author(s):  
Zheng-Ian Lin ◽  
Ching-Wen Lou ◽  
Yi-Jun Pan ◽  
Chien-Teng Hsieh ◽  
Chien-Lin Huang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Crystalline Structure ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Scanning Calorimetry ◽  
Crystallization Behaviors ◽  
Walled Carbon Nanotubes ◽  
Thermal Stability Of

This study adopts the melt compounding method to prepare /mutli-walled carbon nanotubes composites. The effects of different lengths of the mutli-walled carbon nanotubes on the isothermal crystallization behaviors, crystalline structure, and thermal stability of the polypropylene/mutli-walled carbon nanotubes composites are examined. The PLM results show that the combination of mutli-walled carbon nanotubes prevents the growth of polypropylene spherulites, and thus results in a small size of spherulites. The differential scanning calorimetry results show that the short (S-) or long (L-) mutli-walled carbon nanotubes can function as the nucleating agent of polypropylene, which accelerates the crystallization rate of polypropylene. Avrami theory analyses indicate that the addition of short-mutli-walled carbon nanotubes particularly provides polypropylene/mutli-walled carbon nanotubes composites with a high crystallization rate. The X-ray diffraction results show that the combination of mutli-walled carbon nanotubes does not pertain to the crystal structure. The TGA test results show that long-mutli-walled carbon nanotubes outperform short -mutli-walled carbon nanotubes in improving the thermal stability of polypropylene, and both can significantly improve it.

Differential Scanning Calorimetry (DSC) Analysis of Abaca Fibre (Musa Textile Nee) Reinforced High Impact Polystyrene (HIPS) Composites

2011 ◽  
Vol 295-297 ◽  
pp. 929-933 ◽  
Author(s):  
E.H. Agung ◽  
S.M. Sapuan ◽  
M.M.H. Megat Ahmad ◽  
H.M.D.K. Zaman ◽  
U. Mustofa
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Optimum Condition ◽  
Amorphous State ◽  
Heat Content ◽  
High Impact ◽  
Glass Transitions ◽  
Scanning Calorimetry ◽  
High Impact Polystyrene

Differential scanning calorimetry (DSC) was used to study the thermal behaviour of abaca fibre reinforced high impact polystyrene (HIPS) composites. Thermal analysis is based upon the detection of changes in the heat content (enthalpy) and the glass transition temperature (Tg) of optimum condition of abaca fibre reinforced HIPS composites. In this research, glass transitions temperature (Tg) of neat HIPS occurred below the Tg of optimum condition of composites as the temperature of an amorphous state. The endothermic peak of composites was in to range 430-435°C including neat HIPS and it observed that enthalpy of abaca fibre reinforced HIPS composites yielded below the neat HIPS 748.79 J/g.

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