scholarly journals Study on Thermal Decomposition Behaviors of Terpolymers of Carbon Dioxide, Propylene Oxide, and Cyclohexene Oxide

2018 ◽  
Vol 19 (12) ◽  
pp. 3723 ◽  
Author(s):  
Shaoyun Chen ◽  
Min Xiao ◽  
Luyi Sun ◽  
Yuezhong Meng
Keyword(s):  
Carbon Dioxide ◽  
Thermal Stability ◽  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
Propylene Carbonate ◽  
Cyclohexene Oxide ◽  
Block Polymers ◽  
Rate Method ◽  
Poly Propylene ◽  
Thermal Stability Of

The terpolymerization of carbon dioxide (CO2), propylene oxide (PO), and cyclohexene oxide (CHO) were performed by both random polymerization and block polymerization to synthesize the random poly (propylene cyclohexene carbonate) (PPCHC), di-block polymers of poly (propylene carbonate–cyclohexyl carbonate) (PPC-PCHC), and tri-block polymers of poly (cyclohexyl carbonate–propylene carbonate–cyclohexyl carbonate) (PCHC-PPC-PCHC). The kinetics of the thermal degradation of the terpolymers was investigated by the multiple heating rate method (Kissinger-Akahira-Sunose (KAS) method), the single heating rate method (Coats-Redfern method), and the Isoconversional kinetic analysis method proposed by Vyazovkin with the data from thermogravimetric analysis under dynamic conditions. The values of ln k vs. T−1 for the thermal decomposition of four polymers demonstrate the thermal stability of PPC and PPC-PCHC are poorer than PPCHC and PCHC-PPC-PCHC. In addition, for PPCHC and PCHC-PPC-PCHC, there is an intersection between the two rate constant lines, which means that, for thermal stability of PPCHC, it is more stable than PCHC-PPC-PCHC at the temperature less than 309 °C and less stable when the decomposed temperature is more than 309 °C. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetric analysis/infrared spectrometry (TG/FTIR) techniques were applied to investigate the thermal degradation behavior of the polymers. The results showed that unzipping was the main degradation mechanism of all polymers so the final pyrolysates were cyclic propylene carbonate and cyclic cyclohexene carbonate. For the block copolymers, the main chain scission reaction first occurs at PC-PC linkages initiating an unzipping reaction of PPC chain and then, at CHC–CHC linkages, initiating an unzipping reaction of the PCHC chain. That is why the T−5% of di-block and tri-block polymers were not much higher than that of PPC while two maximum decomposition temperatures were observed for both the block copolymer and the second one were much higher than that of PPC. For PPCHC, the random arranged bulky cyclohexane groups in the polymer chain can effectively suppress the backbiting process and retard the unzipping reaction. Thus, it exhibited much higher T−5% than that of PPC and block copolymers.

Synthesis of Lanthanum Orotate and its Application as PVC Thermal Stabilizer

2021 ◽  
Vol 1032 ◽  
pp. 57-63
Author(s):  
Mansurjon Juraev ◽  
Xiao Ya Zhou ◽  
Xiao Tao Ma ◽  
Cheng Fang ◽  
Ye Qian Ge ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermal Decomposition ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Synergetic Effect ◽  
Decomposition Kinetics ◽  
Stabilization Mechanism ◽  
Thermal Stability Of

The structure of basic lanthanum orotate (LaOr) were characterized by elemental analysis and infrared spectroscopy. The thermal stability of polyvinyl chloride (PVC) was further studied by Congo red method, oven discoloration method and thermogravimetric analysis. The results showed that LaOr could prolong the oven discoloration time of PVC, and the color was not completely blackened until 120 min. It has a good synergetic effect with dibenzoyl methane (DBM), and the best effect is achieved when LaOr/DBM ratio is 1.8/1.2. The thermal decomposition kinetics experiment showed that adding DBM can effectively improve the activation energy of PVC/LaOr. The stabilization mechanism of PVC was studied by absorbing HCl method and infrared spectroscopy. The results showed that LaOr could not only replace the unstable chlorine atoms on PVC, but also promote the long-term thermal stability of PVC by absorbing HCl.

STUDY OF THE THERMAL STABILITY OF AN ORGANIC POLYMER LOW-K MATERIAL

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4441-4444 ◽  
Author(s):  
DONG LU ◽  
ZHENXIANG XING
Keyword(s):  
Carbon Dioxide ◽  
Thermal Stability ◽  
Thermal Decomposition ◽  
Aromatic Hydrocarbon ◽  
Aromatic Compounds ◽  
Polymer Materials ◽  
Organic Polymer ◽  
Copper Metallization ◽  
Low K ◽  
Thermal Stability Of

Polymer low-k materials have been regarded as one of the most promising candidates as interconnect insulator with copper metallization. One of the major problems associated with polymer materials is their poor thermal stability. In this paper, thermal stability of an aromatic hydrocarbon low-k material was studied using TGA, FTIR and thermal desorption-GC-MS techniques. The material is thermally stable at temperatures up to 430°C. At higher temperatures, thermal decomposition of the low-k material is pronounced and the major outgassing species are aromatic compounds and carbon dioxide.

A novel method to improve the thermal stability of poly(propylene carbonate)

2014 ◽  
Vol 5 (14) ◽  
pp. 4245-4250 ◽  
Author(s):  
Jingjing An ◽  
Yucai Ke ◽  
Xinyu Cao ◽  
Yongmei Ma ◽  
Fosong Wang
Keyword(s):  
Thermal Stability ◽  
Propylene Carbonate ◽  
Melt Blending ◽  
Biodegradable Material ◽  
New Finding ◽  
Novel Method ◽  
Poly Propylene ◽  
Thermal Stability Of

The introduction of NP-10P by simple melt-blending can significantly improve the thermal stability of PPC. This new finding will facilitate development and widespread applications of this biodegradable material.

Preparation and Characterization of Poly(propylene carbonate)/Alkali Lignin Composite Sheets by Calendering Process

2011 ◽  
Vol 233-235 ◽  
pp. 1786-1789 ◽  
Author(s):  
Li Sha Pan ◽  
Nai Xu ◽  
Zheng Tian ◽  
Ling Bin Lu ◽  
Su Juan Pang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Propylene Carbonate ◽  
Convenient Method ◽  
Interfacial Interaction ◽  
Alkali Lignin ◽  
Aliphatic Polycarbonate ◽  
Poly Propylene ◽  
Thermal Stability Of

PPC is a new biodegradable aliphatic polycarbonate with poor thermal stability and mechanical properties which is difficult to form sheets or films and so on. Through the addition of alkali lignin, thermal stability and mechanical properties of PPC was improved largely. PPC/ alkali lignin sheets could be prepared. DSC results showed that the thermal stability of PPC was improved by the introduction of alkali lignin. SEM showed good dispersion of alkali lignin particles into PPC matrix that resulted in good miscibility. Improved mechanical properties and thermal stability of PPC/ alkali lignin blends were attributed to stronger interfacial interaction of PPC and alkali lignin. These results indicate that blending PPC with alkali lignin is an efficient and convenient method to improve the properties of PPC.

Thermal Stability of N-Heterocycle-Stabilized Iodanes – A Systematic Investigation

2019 ◽  
Author(s):  
Andreas Boelke ◽  
Yulia A. Vlasenko ◽  
Mekhman S. Yusubov ◽  
Boris Nachtsheim ◽  
Pavel Postnikov
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Systematic Investigation ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation. </p>

Non-Isothermal Decomposition Kinetic of Polypropylene/Hydrotalcite Composite

2019 ◽  
Vol 19 (11) ◽  
pp. 7493-7501 ◽  
Author(s):  
Sheng Xu ◽  
Min Zhang ◽  
Siyu Li ◽  
Moyu Yi ◽  
Shigen Shen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
Nitrogen Atmosphere ◽  
Heating Rates ◽  
Decomposition Reactions ◽  
Kinetic And Thermodynamic Parameters ◽  
Málek Method ◽  
Boundary Reaction ◽  
Phase Boundary Reaction ◽  
Thermal Stability Of

P3O5-10 pillared Mg/Al hydrotalcite (HTs) as a functional fire-retarding filler was successfully prepared by impregnation-reconstruction, where the HTs was used to prepare polypropylene (PP) and HTs composite (PP/HTs). Thermal decomposition was crucial for correctly identifying the thermal behavior for the PP/HTs, and studied using thermogravimetry (TG) at different heating rates. Based on single TG curves and Málek method, as well as 41 mechanism functions, the thermal decompositions of the PP/HTs composite and PP in nitrogen atmosphere were studied under non-isothermal conditions. The mechanism functions of the thermal decomposition reactions for the PP/HTs composite and PP were separately “chemical reaction F3” and “phase boundary reaction R2,” which were also in good agreement with corresponding experimental data. It was found that the addition of the HTs increased the apparent activation energy Ea of the PP/HTs comparing to the PP, which improved the thermal stability of the polypropylene. A difference in the set of kinetic and thermodynamic parameters was also observed between the PP/HTs and PP, particularly with respect to lower ΔS≠ value assigned to higher thermal stability of the PP/HTs composite.

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