Key Laboratory of Advanced Civil Engineering Materials

Key Laboratory of Advanced Civil Engineering Materials


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Kong Y.,Tongji University | Qiu T.,Tongji University | Qiu J.,Tongji University | Qiu J.,Key Laboratory of Advanced Civil Engineering Materials
Applied Surface Science | Year: 2013

The hollow activated carbon fibers (HACF) were prepared by using commercial polypropylene hollow fiber (PPHF) as the template, and phenol-formaldehyde resin (PF) as carbon precursors. Final HACF was formed through the thermal decomposition and carbonization of PF at 700°C under the nitrogen atmosphere, and activation at 800°C with carbon dioxide as the activating agent, consecutively. Then, carbon nanotubes (CNTs) were grown by chemical vapor deposition (CVD) techniques using the as-grown porous HACF as substrate. The growth process was achieved by pyrolyzing ethanol steam at 700°C using nickel as catalyst. Finally, CNTs was grown successfully on the substrate, and a novel tree-like micro-nano carbonous structure CNTs/HACF was fabricated. The as-grown HACF and micro-nano CNTs/HACF were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TG), respectively. Moreover, the formation mechanisms were also discussed. © 2012 Elsevier B.V. All rights reserved.


Wang G.-J.,Tongji University | Wang G.-J.,Key Laboratory of Advanced Civil Engineering Materials | Jin J.-Q.,Tongji University
Xinxing Tan Cailiao/New Carbon Materials | Year: 2012

Multiwalled carbon nanotubes (MWCNTs) were oxidized by an acid mixture (concentrated H 2SO 4: HNO 3=3:1 v/v) to form carboxyl groups, which were then reacted with anhydride ethylene diamine by an amidation reaction to introduce amine end groups that were subsequently grafted to polyethylene/maleic anhydride copolymer (PE-g-MA) to increase the dispersion of the modified MWCNTs in a polyethylene (PE) matrix. The chemical modification of the MWCNTs was verified by FTIR, XPS and Raman spectroscopy. The modified MWCNT/PE composites exhibited an electrical percolation threshold at 0.67 vol% MWCNTs. The volume resistivities of the modified MWCNT/PE composites decreased from 10 16 to 10 5 Ω·m with increasing MWCNT content from 0.1 to 1.2 vol%.


Wang G.,Key Laboratory of Advanced Civil Engineering Materials | Wang G.,Tongji University | Yang J.,Tongji University
Surface and Coatings Technology | Year: 2010

Modified expandable graphite (MEG, expandable graphite modified by polyethylene glycol) was used as modifier to improve the fire protection of intumescent fire resistive coating. The FTIR spectra, TGA analysis and SEM images well demonstrated that the surface of EG flakes was successfully modified by polyethylene glycol. After adding 4. wt.% EG or MEG into the coatings, the thermal degradation and char formation of the coatings were investigated in detail by using TGA, XRD, X-ray fluorescence spectrometry (XRF) and SEM. The TGA results showed that the addition of EG and MEG could improve the thermal degradation of the coatings and enhanced the anti-oxidation of the char layers at high temperature. The XRF results showed that anti-oxidation of the coatings was improved by adding EG or MEG. The SEM images demonstrated that the cell size of the char layer increased and the cell size distribution of the char layer became narrow after adding MEG into the coating. © 2010 Elsevier B.V.


Wang P.,Key Laboratory of Advanced Civil Engineering Materials | Feng S.,Key Laboratory of Advanced Civil Engineering Materials | Liu X.,Key Laboratory of Advanced Civil Engineering Materials
Kuei Suan Jen Hsueh Pao/Journal of the Chinese Ceramic Society | Year: 2013

Backscattered electron imaging and analysis (BSE-IA) is invaluable in cement research due to its ability of qualitative and quantitative analysis. For BSE-IA, polished specimens of cement pastes should be prepared first. The accuracy of BSE-IA is mainly determined by the quality of flat-polished specimens. The requirements for quanlified flat-polished specimens and its effect on the BSE-IA were described. In addition, some factors influencing the epoxy intrusion depth aiming at slag cement paste were investigated. It was showed that epoxy intrusion played a key role in preparing qualified specimens since without epoxy filling other defects existed meanwhile such as particles fall-off, low planness. The use of appropriate measurements could improve the epoxy intrusion.


Wang G.,Key Laboratory of Advanced Civil Engineering Materials | Wang G.,Tongji University | Yang J.,Tongji University
Surface and Coatings Technology | Year: 2010

The combination of epoxy emulsion and self-crosslinked silicone acrylate (SSA) emulsion was used as mixed binder for preparing water-borne intumescent fire resistive coating. The influences of binders on the properties and char formation of the coatings were investigated in detail by using thermogravimetry (TG), scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray fluorescence spectrometry (XRF), rheological measurement, fire protection test and anticorrosion property test. It was found that the fire protection and foam structure of the coating was significantly improved by adding 14% SSA (by mass). The TG results showed that adding SSA increased the residue weights of the coatings. The XRF results demonstrated that anti-oxidation of the coatings was improved by adding SSA into the mixed binders. The results of anticorrosion property test indicated that the anticorrosion property of the coatings was enhanced with increase of content of SSA. Crown Copyright © 2009.


Wang G.,Tongji University | Wang G.,Key Laboratory of Advanced Civil Engineering Materials | Huang Y.,Tongji University | Hu X.,Tongji University
Progress in Organic Coatings | Year: 2013

A mixture (denoted as PX) of phosphates was prepared by the reaction of phosphoric acid and a kind of bicyclic pentaerythritol phosphate (PEPA, 1-oxo-1-phospha-2,6,7-trioxabicyclo[2.2.2]-4-hydroxymethyl octane). Then PX was successfully copolymerized with PEG200 to achieve a novel phosphorus-containing polymer (denoted as PX-co-PEG). 31P NMR, 1H NMR and FT-IR analysis results showed that there were 38.7 wt.% PEPA phosphates and 61.3 wt.% pentaerythritol biphosphates in the PX mixture. The result of GPC indicated that the molecular formula of PX-co-PEG could be noted as PX 2.0PEG 3.0. Fire protection test results proved that PX-co-PEG modified amino resin applied on the plywood boards effectively extended the protection time over flame. The decomposition process of fire resistant coating was studied by thermogravimetric analysis and FT-IR which could be divided into three characteristic temperature stages. The solid residue was kept to be 14.6 wt.% at 787 °C. © 2012 Elsevier B.V.


Wang G.,Tongji University | Wang G.,Key Laboratory of Advanced Civil Engineering Materials | Yang J.,Tongji University
Progress in Organic Coatings | Year: 2011

Glass flake (GF) was used as a modifier to improve the fire protection and water resistance of waterborne intumescent fire resistive coating. The influences of GF on the properties of the coatings were investigated in detail by using TGA, XRD, X-ray fluorescence spectrometry (XRF), SEM and fire protection test. The TGA results proved that addition of GF could enhance the anti-oxidation of the char layers and increase the residue weights of the coatings. The XRF results indicated that anti-oxidation of the coatings modified by GF was improved. The SEM images demonstrated that addition of GF could improve the foam structure of the coatings. After immersed in water over 600 h, the results showed that the thermal stability and fire protection of the coating without GF were significant decreased, but the coatings modified by GF could still maintain the excellent intumescent effect and fire protection. © 2010 Elsevier B.V. All rights reserved.


Zheng X.,Tongji University | Wang G.,Tongji University | Wang G.,Key Laboratory of Advanced Civil Engineering Materials | Xu W.,Tongji University
Polymer Degradation and Stability | Year: 2014

The improvement of the flame retardancy of rigid polyurethane foam (RPUF) has been attracted much attention, and addition of phosphorus flame retardants and/or nanomaterials is one of good methods. Two systems have been adopted to improve the flame retardancy of RPUF in this work. Firstly, the phosphorus flame retardant system of ammonium polyphosphate (APP) and triphenyl phosphate (TPP) is introduced to promote the char-forming property of RPUF during its combustion. Thermogravimetric analysis (TGA) results show that the thermal stability and the char yield of RPUF have been extremely improved by addition of APP-TPP system. Secondly, organically-modified montmorillonite (OMMT), possessing of its particular nano-layer structure, is incorporated as an additional filler in the APP-TPP/RPUF system to further improve the flame retardancy of RPUF. The CONE combustion tests indicate that 5% OMMT/8% APP-4% TPP/RPUF (ATO-845) exhibit the longest combustion duration time, slowest heat release rate and lowest total smoke production among pure RPUF (ATO-000), 5% OMMT/RPUF (ATO-005), 8% APP-4% TPP/RPUF (ATO-840), and ATO-845 samples. The extraordinary flame retardant performance of ATO-845 is attributed to the synergy effect between OMMT and APP-TPP system in forming a mass of integrated, stable and tight charred layers during the combustion of RPUF. © 2014 Elsevier Ltd. All rights reserved.


Niu M.,Tongji University | Wang G.J.,Tongji University | Wang G.J.,Key Laboratory of Advanced Civil Engineering Materials
Advanced Materials Research | Year: 2013

In this article, a series of novel phenolic resin modified with cardanol were synthesized. The influence of reaction condition and cardanol content on the structure and properties of phenolic resin was evaluated. The nanocomposite phenolic foam was then prepared by infusing the organo-modified montmorillonite (OMMT) in the synthesis step of cardanol phenolic resin to produce nanocomposite phenolic foams. These phenolic foams were characterized by FTIR, XRD, SEM and TGA. And the mechanical properties and fire performance of these nanocomposite foams were also measured. The results showed that the cardanol component could reduce the crosslink density of phenolic foam and thus improve the mechanical properties; the OMMT platelets were 3~10μm in diameter and 40~50nm in thick. These platelets can exfoliated and dispersed well in the nanocomposite due to the hydrogen-bonding between organo-modifier and phenolic matrix and improve the thermal stability, fire resistance and also the mechanical properties of nanocomposite foam. © (2013) Trans Tech Publications, Switzerland.


Wang G.,Tongji University | Wang G.,Key Laboratory of Advanced Civil Engineering Materials | Xu W.,Tongji University
Polymer Degradation and Stability | Year: 2013

Char-forming property of PU rigid foams, which can be assessed by char residue (%) when PU is burned at certain temperature, was studied by TG and DTG. The results showed that pure PU rigid foam had low char residue of only 17%, while 33% of char residue was achieved when PU rigid foam was modified by adding 8 wt% of 1-oxo-2,6,7-trioxa-1-phosphabicyclo[2,2,2] octane (PEPA), which is a caged bicyclic phosphate. The experiment results of FTIR and XPS showed that the PEPA modified PU rigid foam could be dehydrogenated and dehydrated at temperature between 380 and 450 C, resulting in the increase of char residue of PU rigid foam. Further study also revealed that the addition of CaCO3 nanoparticles could enhance the char stability when the PEPA modified PU rigid foam was being burned. The mechanism was investigated and it was found that the enhanced char stability could be attributed to the limited permeation of oxygen caused by the formation of calcium phosphate and calcium pyrophosphate by the reaction of PEPA and CaCO3 at high temperature, which were covered on or buried in the char layer. © 2013 Elsevier Ltd. All rights reserved.

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