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Liu Y.-F.,Beijing Institute of Technology | Chen Y.,Beijing Institute of Technology | Shi L.,Guangzhou Kingfa Science and Technology Co. | Yao W.-S.,Beijing Institute of Technology
Propellants, Explosives, Pyrotechnics | Year: 2012

Three novel long-chain alkyl bonding agents including 1,1′- dodecylimino-bis[3-[bis(2-hydroxyethyl)amino]-2-propanol (DHAP), 1-acetyl-5-dodecyl-octahydro-1,5-diazocine-3,7-diol (ADODD) and 1,3-bis(dodecylimino)-5,5-dimethyl-2,4-imidazolidinedione (DDID) were synthesized by modification of laurylamine. Interaction energies between bonding agents and RDX were calculated and compared using the molecular dynamics method. Effects of coating by different bonding agents on characteristic absorption peaks of RDX were analyzed by micro-infrared spectroscopy. The adhesion degrees of different bonding agents on the surface of RDX solid particles were calculated by XPS methods. The three prepared bonding agents were added to the HTPB/RDX/Al propellant and their effects on σ, ε m, ε b and Ω (the adhesion index between filling particles and binder matrix) value of propellant were studied. Simulation and experimental results showed that those three types of long-chain alkyl bonding agents exhibit a strong interaction with RDX, with highest interaction potencial observed for DHAP, followed by DDID and ADODD. In addition, the current study demonstrated that results obtained by molecular dynamics simulation were in very good agreement with the experimental data. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Yun-Fei L.,Beijing Institute of Technology | Yu C.,Beijing Institute of Technology | Liang S.,Guangzhou Kingfa Science and Technology Co. | Wei-Shang Y.,Beijing Institute of Technology
Journal of Energetic Materials | Year: 2014

Composite particles (BAP) of boron (B) coated with ammonium perchlorate (AP) were prepared by recrystallization and their structures were characterized using Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and laser particle size analyses. The results indicated that AP was well coated on the boron surface. The effects of different contents of BAP coated with different amounts of AP on the rheological properties of HTPB/B/AP composite slurries were also studied. The results show that addition of BAP distinctly decreased the slurries' viscosities and improved their processing properties, which were more obvious when 9.73% AP was coated on the surface of boron and the amount of BAP was 20%. © 2014 Copyright Taylor and Francis Group, LLC.


Liu Y.-F.,Beijing Institute of Technology | Chen Y.,Beijing Institute of Technology | Shi L.,Guangzhou Kingfa Science and Technology Co. | Yao W.-S.,Beijing Institute of Technology
Cailiao Gongcheng/Journal of Materials Engineering | Year: 2012

N, N-di-2, 3-epoxypropyl dodecylamine (EDA), an important intermediate of the surfactants with good chemical reactivities, was synthesized via ring-closing reaction of the chlorohydrin, which was prepared through the ring-opening reaction of the epichlorohydrin with dodecylamine, in the KOH-H 2O solutions. The structure of the products were characterized through FTIR, 1H-NMR and 13C-NMR spectrum. Influence of the reaction conditions, such as temperature and time of the ring-closing reaction, amount of the alkali and epichlorohydrin, types of the alkali, etc. on the content of EDA in the produces were studied, and then the optimal conditions for synthesizing N, N-di-2, 3-epoxypropyl dodecylamine was defined.


Cheng R.-X.,Northeast Forestry University | Li Y.,Guangzhou Kingfa Science and Technology Company | Wang Q.-W.,Northeast Forestry University | Zhang L.,Northeast Forestry University
Journal of Applied Polymer Science | Year: 2012

This article studied the bonding properties of poly(vinyl chloride) (PVC)-based wood-plastic composite (WPC) materials bonded with epoxy adhesive. The results show that the dry compression shear strength of bonded specimens glued with epoxy adhesive could reach 72% of the strength of the PVC-based WPCs themselves. That meant the bonding connection with epoxy resin was feasible in the application of PVC-based WPCs. The results show that the compression shear strength after the damp cycle was 0.981 times the compression shear strength without any treatment. In addition, the retention rate of the compression shear strength was 87.7% after the UV aging test process set in this study. In this study, the surface morphologies of bonded specimens glued with epoxy adhesive after a boiling-drying treatment and UV aging were observed by scanning electron microscopy (SEM). The results of SEM show that the glue line became rough in different degrees after the damp cycle and UV aging. Copyright © 2011 Wiley Periodicals, Inc.


Yang L.,South China University of Technology | Chen H.,South China University of Technology | Jia S.,South China University of Technology | Lu X.,South China University of Technology | And 5 more authors.
Journal of Applied Polymer Science | Year: 2014

Elastomer ethylene-butylacrylate-glycidyl methacrylate (PTW) containing epoxy groups were chosen as toughening modifier for poly(butylene terephthalate) (PBT)/polyolefin elastomer (POE) blend. The morphology, thermal, and mechanical properties of the PBT/POE/PTW blend were studied. The infrared spectra of the blends proved that small parts of epoxy groups of PTW reacted with carboxylic acid or hydroxyl groups in PBT during melt blending, resulting in a grafted structure which tended to increase the viscosity and interfere with the crystallization process of the blend. The morphology observed by scanning electron microscopy revealed the dispersed POE particles were well distributed and the interaction between POE and PBT increased in the PBT/POE/PTW blends. Mechanical properties showed the addition of PTW could lead to a remarkable increase about 10-times in impact strength with a small reduction in tensile strength of PBT/POE blends. Differential scanning calorimetry results showed with increasing PTW, the crystallization temperature (Tc) and crystallinity (Xc) decreased while the melting point (Tm) slightly increased. Dynamic mechanical thermal analysis spectra indicated that the presence of PTW could improve the compatibility of PBT/POE blends. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40660. Copyright © 2014 Wiley Periodicals, Inc.


Mai J.,South China University of Technology | Zhu J.,Guangzhou Kingfa Science and Technology Co. | Wang L.,South China University of Technology
Journal of Macromolecular Science, Part B: Physics | Year: 2014

The reaction product EPDM-g-SAN, synthesized by suspension graft copolymerization of styrene (St) and acrylonitrile (AN) in the presence of ethylene-propylene-diene terpolymer (EPDM), was blended with a commercial styrene-acrylonitrile copolymer (SAN resin) to prepare AES blends with high impact strength. The effects of AN mass percentage in the St-AN comonomer mixture (f AN), EPDM mass percentage in the feed of EPDM and St-AN (f EPDM) and reaction time on monomer conversion ratio (CR), grafting ratio (GR), and AES notched Izod impact strength were characterized. The notched Izod impact strength of AES containing 15 wt% EPDM reached its maximum with f AN of 40 wt% and f EPDM of 45 wt%; this was attributed to the polarity of the SAN copolymer obtained being appropriate with that of the SAN resin matrix. The dependences of GR and the notched Izod impact strength of AES containing 25 wt% EPDM on the reaction time were in rough agreement. The effect of EPDM content on the AES notched Izod impact strength indicated that the brittle-ductile transition of AES occurred for an EPDM content from 12.5 to 15 wt%. TEM and SEM analysis showed that the phase structure of AES exhibited a "salami" like structure, and the toughening mechanism of AES was shear yielding of the SAN resin matrix, which endowed AES with excellent toughness. © 2014 Taylor and Francis Group, LLC.


Liu W.,South China University of Technology | Wang L.,South China University of Technology | Cai T.,Guangzhou Kingfa Science and Technology Co. | Zhang A.,South China University of Technology | Zeng X.,Guangzhou Kingfa Science and Technology Co.
Journal of Macromolecular Science, Part B: Physics | Year: 2010

Ethylene-propylene-diene-methyl methacrylate/acrylonitrile terpolymers (EPDM-g-MAN) were synthesized by comonomers methyl methacrylate and acrylonitrile (MMA-AN) grafted on EPDM macromolecules with solution graft copolymerization. The engineering plastics of the blend of EPDM-g-MAN with SAN (AEMS) were prepared by blending EPDM-g-MAN with SAN resin. The effect of AN/MMA-AN weight percentage (fAN) on monomer conversion ratio, grafting ratio, and grafting efficiency of the graft copolymerization and the notched Izod impact strength of AEMS were investigated. The notched Izod impact strength of AEMS, prepared by blending SAN with EPDM-g-MAN, was synthesized under our optimum S2 reaction conditions, with EPDM/MMA-AN weight proportion of 50/50 and fAN of 10 wt%, presenting a peak with the maximum value of 61.0 kJ/m2. The microstructure of AEMS prepared with S2 reaction conditions showed that when the polarity of EPDM-g-MAN was appropriate, the EPDM phase formed a pseudocontinuous phase in the SAN matrix and the interfacial adhesion was strong, which could induce shear yielding of the SAN matrix. Differential scanning calorimetry analysis showed that there was good compatibility between SAN resin and EPDM-g-MAN synthesized with fAN of 10 wt% and a EPDM/MMA-AN weight ratio of 50/50. Copyright © 2010 Taylor & Francis Group, LLC.


Xiong K.,South China University of Technology | Zhu Y.-P.,South China University of Technology | Wang L.-S.,South China University of Technology | Cai T.-M.,Guangzhou Kingfa Science and Technology Co. | And 2 more authors.
Gaofenzi Cailiao Kexue Yu Gongcheng/Polymeric Materials Science and Engineering | Year: 2010

PEB-g-MAN was prepared by graft copolymerization of methyl methacrylate (MMA) and acrylonitrile(AN) onto poly(ethene-co-1-butene) (PEB) with suspension polymerization. The components of the grafted copolymer were separated by different solvent and were qualitative analyzed using Fourier transform infrared spectrum(FT-IR). The effect of AN/(MMA+AN) ratio(fAN )on the monomer conversion ratio (CR), average grafting ratio (GR), grafting efficiency (GE), rubber's grafting ratio(GRR), ture grafting ratio(GRT) of copolymerization and content of components in the grafted polymerization product was investigated. The molecular weight of the grafted polymerization product was characterized by gel permeation in chromatography(GPC). The results show that the main elementary reactions in PEB/MMA-AN grafting reaction system are graft copolymerization of PEB/MMA-AN, graft polymerization of PEB/MMA, copolymerization of MMA and AN, homopolymerization of MMA, and there are no grafting polymerization of PEB/AN, homopolymerization of AN and crosslinking reaction of PEB.


Zhu Y.-P.,South China University of Technology | Wang L.-S.,South China University of Technology | Zhang A.-Q.,South China University of Technology | Wang X.,South China University of Technology | And 2 more authors.
Journal of Macromolecular Science, Part B: Physics | Year: 2010

Poly(ethene-co-1-butene)-graft-methyl methacrylate-acrylonitrile (PEB-g-MAN), synthesized by suspension grafting copolymerization of methyl methacrylate and acrylonitrile onto PEB, was blended with styrene-acrylonitrile copolymer (SAN). The mechanical properties, phase structure, toughening mechanism, miscibility, and thermal stability of the SAN/PEB-g-MAN blends were studied using a pendulum impact tester, tension tester, scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TG). The results showed that PEB-g-MAN has an excellent toughening effect on SAN resin. The notched impact strength of the blends (containing 25 wt% PEB) was 63.3 kJ/m2, which was nearly 60 times that of SAN resin. The brittle-ductile transition of SAN/PEB-g-MAN blends occurred when the weight percentage of PEB was between 17.5 and 20 wt%. SAN and PEB-g-MAN were partially miscible. The toughening mechanism of the blends changed with the PEB content. When the PEB content was low, the toughening mechanism of the blends was branching and termination of cracks with slight cavitation. As the content of PEB increased, the toughing mechanism gradually changed from branching and termination of crack with slight cavitation to both branching and termination of crack and cavitation, to extensive cavitation, and finally to shear yielding accompanied by cavitation. The phase structure of the blends changed from a sea-island'' structure to a cocontinuous structure as the PEB content increased. ATG analysis showed that the thermal properties of the SAN resin in the blends were enhanced by adding the PEB-g-MAN. Copyright © Taylor and Francis Group, LLC.


Xiong K.,South China University of Technology | Zhu Y.,South China University of Technology | Wang L.,South China University of Technology | Cai T.,Guangzhou Kingfa Science and Technology Co. | And 2 more authors.
Journal of Macromolecular Science, Part B: Physics | Year: 2012

Poly(ethene-co-1-butene)-graft-methyl methacrylate-acrylonitrile (PEB-g-MAN) was prepared by suspension grafting copolymerization of methyl methacrylate (MMA) and acrylonitrile(AN) onto PEB. PEB-g-MAN/SAN resin blends (ABMS) were prepared by blending PEB-g-MAN with styrene-acrylonitrile copolymer (SAN resin). The effects of AN/(MMA+AN) feed ratio (fAN), PEB/(PEB+MMA+AN) feed ratio (fPEB) and benzoyl peroxide (BPO) dosage on the monomer conversion ratio (CR), rubber's grafting ratio (GR), grafting efficiency (GE) of the copolymerization and the toughening effect of PEB-g-MAN on the SAN resin were investigated. FTIR quantitative analysis showed that when the weight percent of AN unit in the unextracted product was 21.5 wt% with fAN of 25 wt%, the toughening effect of unextracted PEB-g-MAN on SAN resin was the highest. Gel permeation chromatography (GPC) analysis showed that when fAN was 25 wt%, the grafted copolymer had the lowest molecular weight and ABMS had highest toughness. Transmission electron microscopy (TEM) analysis showed that the highest toughness occurred when the phase structure of ABMS was cocontinuous with fAN of 25 wt%. When fAN was 25 wt% PEB-g-MAN domains have numerous small SAN domains in them, which was occlusion structure. Scanning electron microscopy (SEM) analysis indicated that the ABMS fracture surfaces had plastic flow visible, which looked like a craze fibers morphology, for the sample with highest impact strength (fAN = 25 wt%). Dynamic mechanical thermal analysis (DMA) showed that the miscibility of the PEB phase and SAN phase improved after graft copolymerization of MMA and AN onto PEB. © 2012 Copyright Taylor and Francis Group, LLC.

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