Time filter

Source Type

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
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.

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 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 Co. | 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.

Discover hidden collaborations