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Wyszukujesz frazę "pot life" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
Influence of Bismuth Complex Catalysts on the Cure Reaction of Hydroxyl-terminated Polyether-based Polymer Bonded Explosives
Autorzy:
Ou, Y.
Jiao, Q.
Yan, S.
Zhu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/358587.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HTPE
bismuth complex catalyst
pot-life
manufacture time reduction
mechanical and thermal characteristics
Opis:
The kinetics of catalyzed urethane-forming reactions of hydroxyl-terminated polyether (HTPE) with toluene di-isocyanate (TDI) in the presence of bismuth complex catalysts was investigated by non-isothermal differential scanning calorimetry (DSC). Fourier transform infrared spectroscopy (FTIR) was employed to monitor the chemical interactions of relevant groups. The kinetic parameters, including the apparent activation energy (Ea) and reaction rate constants (k) at typical temperatures calculated by the Kissinger and Crane methods, were used to evaluate the catalytic activities of triphenylbismuth (TPB) and tris(3-ethoxyphenyl)bismuthine (TEPB). The variations of Ea were studied to obtain an insight into the consistency of catalytic mechanism for the bismuth complex catalysts. The viscosity build-up of HTPE-based polymer bonded explosive (PBX) slurry was then measured to verify the catalytic activity and the pot-life during an actual manufacturing process, which fitted with the kinetics of the catalyzed cure reaction. The cure process was evaluated by the hardness of the PBX grains maintained at a temperature below typical manufacturing conditions. The results showed that TEPB is an effective catalyst, reducing the Ea of the cure reaction and the manufacturing temperature and time with an acceptable pot-life. The mechanical, thermal characteristics and compatibility of the HTPE-based PBXs were also investigated. The results suggest that TEPB is compatible with HTPE-based PBXs and contributes to improving the mechanical properties and thermal safety.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 1; 131-149
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies on the High Performance Characteristics of an Aluminized Ammonium Perchlorate Composite Solid Propellant Based on Nitrile Butadiene Rubber
Autorzy:
Sudhir, Singh
Sidharth, Raveendran
Dhirendra, Kshirsagar R.
Gupta, Manoj
Chetan, Bhongale
Powiązania:
https://bibliotekanauki.pl/articles/27787902.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
composite solid propellant
dibutyl phthalate
high density specific impulse
nitrile-butadiene rubber
pot life
spreadibility
yield stress
Opis:
n the present study, a high performance composite solid propellant formulation was prepared based on nitrile butadiene rubber (NBR) and dibutyl phthalate (DBP) plasticizer, which has a longer pot life and high density specific impulse. The developed cost effective novel binder system was prepared with readily available raw materials (NBR and DBP). The formulation of the composition was performed by varying the content of the NBR/DBP binder in the range of 14-20%. The rocket performance characteristics were determined theoretically using PROPEP and compared with those of an HTPB based propellant. The rheological, mechanical, physical, ballistic and thermal properties of the NBR/DBP propellant were studied and compared with literature data for similar compositions based on an HTPB/dioctyl adipate (DOA) binder. The yield stress was determined by spreadibilty measurements, and indicated the superiority of this binder based propellant over existing composite propellants. It was concluded that following decreasing the content of the NBR/DBP binder in the propellant from 20 to 14%: in the range 58.83-78.45 bar (5.883-7.845 MPa), the pressure index increased from 0.159 to 0.371, – at 68.64 bar (6.864 MPa), the burning rate increased from 4.10 to 6.54 mm/s, but the theoretical specific impulse value did not change significantly (258.0259.8 s), – the tensile strength and E-modulus increased from 6.03 to 9.88 (0.591-0.969) to and from 18.00 to 75.00 kgf/cm2 (1.765 to 7.355 MPa), respectively. Moreover, a DSC and TGA study indicated a lower decomposition temperature for the NBR/DBP propellant compared to the HTPB propellant. The NBR/DBP propellant exhibited a pot life more than double that of a conventional HTPB/ DOA based propellant.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 4; 492--511
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Epoxy adhesive formulations using latent imidazole metal cation complexes
Autorzy:
Pilawka, R.
Maka, H.
Powiązania:
https://bibliotekanauki.pl/articles/779382.pdf
Data publikacji:
2011
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
kleje epoksydowe
utwardzacze
kompleksy imidazoli
wytrzymałość na ścinanie
epoxy adhesives
latent curing agent
imidazole complexes
pot life
shear strength
Opis:
Complexes of 2-methylimidazole with cations from several metal sulfates were prepared and investigated as curing agents for epoxy resins. The reactivity of one-part formulations of these complexes with a bisphenol A type epoxy resin was determined by the differential scanning calorimetry and the pot life observed by viscosity measurements. Tensile lap shear tests at room temperature and at 120°C were used to evaluate the adhesive strength of the formulations directly after preparation as well as after one and three months of storage at room temperature. The DSC measurements showed much lower reactivity (7 - 32%) and higher reaction temperatures of the complex formulations in comparison to the mixtures with pure 2-methylimidazole. The viscosity of most formulations remained almost unchanged over the observed period of three months. The adhesive strength of the freshly prepared complex formulations is comparable to a formulation with pure 2-methylimidazole and decreases over time, depending on the type of metal cation and the cation-to-imidazole molar ratio. The obtained results indicate that complexes of 2-methylimidazole with cations are suitable as latent curing agents for epoxy resins.
Źródło:
Polish Journal of Chemical Technology; 2011, 13, 1; 63-66
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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