Test Method for Vapor Pressure-Temperature Relationship and Initial Decomposition Temperature of Liquids by Isoteniscope

Polyvinylamine (PVAm) and polyvinylamine chloride (PVAm•HCl) were synthesized by Hofmann degradation of polyacrylamide (PAM). The reaction condition is gentle and the operation is safe, simple and economical so that it is a good reaction method. The chemical structures and thermal properties of the polymers were studied by Fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance spectrometer (NMR), X-ray diffractmeter (XRD) and thermogravimetric analyzer (TGA). Synthesis of PVAm•HCl was confirmed by the intensities of the characteristic peak of -CONH2 decreased and the appearance of a new absorption peak at 1530cm-1 (due to N-H bond of -NH3+ ) in the FTIR spectrum, the appearance of the characteristic absorption peaks of carbon atoms in the 13C NMR spectrum, the appearance of chemical shift assignments of proton in 1H NMR spectrum and the appearance of characteristic dispersing diffraction peak between 22.5° to 25.2° in the XRD spectrum, respectively. PAM had three decomposing stages, but PVAm•HCl had two decomposing stages. TG curve of PAM and PVAm•HCl showed that the initial decomposition temperature were 190oC and 140oC, respectively. The thermal stability of PVAm•HCl was poorer than that of PAM.

Polyimide nanocomposites with functionalized graphene sheets

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705717720970 ◽

2017 ◽

Vol 31 (6) ◽

pp. 837-861 ◽

Cited By ~ 3

Author(s):

Jin-Hae Chang

Keyword(s):

Electrical Conductivity ◽

Filler Content ◽

Coefficient Of Thermal Expansion ◽

Barrier Properties ◽

Decomposition Temperature ◽

Graphene Sheets ◽

Functionalized Graphene ◽

Hybrid Films ◽

Initial Decomposition Temperature ◽

Transmission Electron Microscopy Analysis

Polyimide (PI) nanocomposites containing two different functionalized graphene sheets (FGSs) were synthesized, and their thermal properties, morphology, oxygen permeability, and electrical conductivity were compared. Hexadecylamine–graphene sheets and 4-amino- N-hexadecylbenzamide–graphene sheets were utilized. Hybrid films were obtained from blended solutions of PI and FGSs, with the filler content with respect to the PI varying from 0 wt% to 10 wt%. The differences in the properties of the PI matrix were then analyzed with respect to filler content. Transmission electron microscopy analysis confirmed that the two FGSs were dispersed homogeneously throughout the polymer matrix, although some FGS aggregates were also formed. Furthermore, it was observed that the addition of small amounts of FGS nanofiller was sufficient to improve the coefficient of thermal expansion, the gas barrier properties, and the electrical conductivity of the hybrid films. In contrast, the glass transition temperature and the initial decomposition temperature of the PI hybrid films continued to decrease with increasing FGS content.

Preparation of Few-Layered WS2 and Its Thermal Catalysis for Dihydroxylammonium-5,5′-Bistetrazole-1,1′-Diolate

Journal of Nanomaterials ◽

10.1155/2019/7458645 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8

Author(s):

Yiping Shang ◽

Wu Yang ◽

Yabei Xu ◽

Siru Pan ◽

Huayu Wang ◽

...

Keyword(s):

Thermal Analysis ◽

Thermal Decomposition ◽

Analysis Data ◽

Decomposition Temperature ◽

Thermal Excitation ◽

Layered Semiconductor ◽

Initial Decomposition Temperature ◽

Thermal Decomposition Behavior ◽

Decomposition Behavior ◽

Catalytic Effects

In this study, few-layered tungsten disulfide (WS2) was prepared using a liquid phase exfoliation (LPE) method, and its thermal catalytic effects on an important kind of energetic salts, dihydroxylammonium-5,5′-bistetrazole-1,1′-diolate (TKX-50), were investigated. Few-layered WS2 nanosheets were obtained successfully from LPE process. And the effects of the catalytic activity of the bulk and few-layered WS2 on the thermal decomposition behavior of TKX-50 were studied by using synchronous thermal analysis (STA). Moreover, the thermal analysis data was analyzed furtherly by using the thermokinetic software AKTS. The results showed the WS2 materials had an intrinsic thermal catalysis performance for TKX-50 thermal decomposition. With the few-layered WS2 added, the initial decomposition temperature and activation energy (Ea) of TKX-50 had been decreased more efficiently. A possible thermal catalysis decomposition mechanism was proposed based on WS2. Two dimensional-layered semiconductor WS2 materials under thermal excitation can promote the primary decomposition of TKX-50 by enhancing the H-transfer progress.

A Study on the Synthesis, Curing Behavior and Flame Retardance of a Novel Flame Retardant Curing Agent for Epoxy Resin

Polymers ◽

10.3390/polym14020245 ◽

2022 ◽

Vol 14 (2) ◽

pp. 245

Author(s):

Yong Sun ◽

Yongli Peng ◽

Yajiao Zhang

Keyword(s):

Flame Retardant ◽

Epoxy Resin ◽

Decomposition Temperature ◽

Isothermal Kinetics ◽

Flame Retardance ◽

Curing Agent ◽

Initial Decomposition Temperature ◽

Limiting Oxygen Index ◽

Epoxy Resin System ◽

Dsc Method

In this work, a flame retardant curing agent (DOPO-MAC) composed of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and methyl acrylamide (MAC) was synthesized successfully, and the structure of the compound was characterized by FT-IR and 1H-NMR. The non-isothermal kinetics of the epoxy resin/DOPO-MAC system with 1% phosphorus was studied by non-isothermal DSC method. The activation energy of the reaction (Ea), about 46 kJ/mol, was calculated by Kissinger and Ozawa method, indicating that the curing reaction was easy to carry out. The flame retardancy of the epoxy resin system was analyzed by vertical combustion test (UL94) and limiting oxygen index (LOI) test. The results showed that epoxy resin (EP) with 1% phosphorus successfully passed a UL-94 V-0 rating, and the LOI value increased along with the increasing of phosphorus content. It confirmed that DOPO-MAC possessed excellent flame retardance and higher curing reactivity. Moreover, the thermal stability of EP materials was also investigated by TGA. With the DOPO-MAC added, the residual mass of EP materials increased remarkably although the initial decomposition temperature decreased slightly.