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Study on the Thermal Stability and Decomposition Kinetics of Polypropylene Glycol – Glycidyl Azide Polymer – Polypropylene Glycol (PPG-GAP-PPG) as a Novel Triblock Copolymer Binder

Ghoroghchian Fahimeh, Bayat Yadollah, Abrishami Fatemeh

Central European Journal of Energetic Materials

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2020

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Vol. 17, no. 2

262--279

EN

In this study, the novel energetic triblock copolymer of polypropylene glycol- glycidyl azide polymer- polypropylene glycol (PPG-GAP-PPG) (Mn= 1419 g·mol–1) was synthesized by cationic ring-opening polymerization of propylene oxide using low molecular weight glycidyl azide polymer (GAP) (MMnn = 1006 g·mol–1) as the initiator and boron trifluoride etherate (BFM3·OEtM2) as the catalyst. The synthesized GAP and triblock copolymer were characterized by Fourier-transform infrared (FT-IR) spectroscopy, gel permeation chromatography (GPC), and nuclear magnetic resonance spectroscopy (1H and 13C NMR). The thermal stability of the triblock copolymer PPG-GAP-PPG was studied by differential scanning calorimetry (DSC) and thermogravimetry (TG). The DSC results showed that the glass transition temperature (TMg) of the triblock copolymer (TMg = −63 °C) was lower than that of neat low molecular weight GAP (Tg = −53 °C). Furthermore, the results indicated that this triblock copolymer is more stable than GAP. The influence of heating rate (10, 20, 30 and 40 °C·min−1) illustrated that increasing the heating rate results in an increase in the triblock copolymer’s decomposition temperature. Non-isothermal methods, proposed by ASTM E698, Flynn-Wall-Ozawa (FWO) and Kissinger, were used to calculate the kinetic parameters, such as activation energy and frequenc factor, for the thermal decomposition of the triblock copolymer PPG-GAP-PPG, using the DSC-DTG were 124.610 and 126.13 kJ·mol–1, respectively.

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Dual Self-Assembly in Strongly Asymmetric A-B-A Triblock Copolymer Melts Studied by Self-Consistent Field Theory and Monte Carlo Simulations

Dzięcielski L., Wołoszczuk S., Banaszak M.

Computational Methods in Science and Technology

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2018

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Vol. 24, No. 4

227--234

EN

Using the Self-Consistent Field Theory (SCFT) we study the dual self-assembly of ABA triblock copolymers melts and compare the numerical results with those obtained by the lattice Monte Carlo simulations. While the results are qualitatively similar for both methods, the simulation times are significantly shorter for the SCFT calculations than those for the corresponding Monte Carlo simulations

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Synthesis and Characterization of PolyNIMMO-HTPB-polyNIMMO Triblock Copolymer as a Potential Energetic Binder

Wang X., Shu Y., Lu X., Mo H., Xu M.

Central European Journal of Energetic Materials

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2018

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Vol. 15, no. 3

456--467

EN

Triblock copolymer polyNIMMO-HTPB-polyNIMMO was synthesized by cationic ring opening polymerization of NIMMO (3-nitratomethyl-3-methyloxetane) in the presence of hydroxyl-terminated polybutadiene catalyzed by BF3·OEt2. The polymer was characterized by FT-IR, 1H NMR, 13C NMR spectroscopy, and GPC. DSC was used to investigate the thermal behaviour of the triblock copolymer and its exothermic decomposition peak was found to be at 215 °C. All of the results indicated that the triblock copolymer polyNIMMO-HTPB-polyNIMMO might serve as a potential energetic propellant binder.

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Mechanical and thermal properties of PP/PBT blends compatibilized with triblock thermoplastic elastomer

Ignaczak W., Wiśniewska K., Janik J., El Fray M.

Polish Journal of Chemical Technology

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2015

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Vol. 17, nr 3

78--83

EN

A linear triblock copolymer, poly(styrene-b-etylene/butylene-b-styrene)(SEBS) thermoplastic elastomer (TPE) grafted with maleic anhydride was used for compatibilization of PP/PBT blends. PP/PBT blends of different mass ratios 60/40, 50/50, 40/60 were mixed with 2.5, 5.0 and 7.5 wt.% of SEBS copolymer in a twin screw extruder. Differential scanning calorimetry and dynamic mechanical analysis were performed to define the phase structure of PP/PBT blends. TPE with a rubbery mid-block shifted the glass transition of PP/PBT blend towards lower temperatures, and significant decrease the crystallization temperature of a crystalline phase of PP component was observed. The influence of the amount of compatibilizer and the blend composition on the mechanical properties (tensile and flexural strengths, toughness and moduli) was determined. Addition of 5 wt.% of a triblock TPE led to a three-fold increase of PP/PBT toughness. A significant increase of impact properties was observed for all materials compatibilized with the highest amount of SEBS copolymer.

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Synteza i badanie właściwości adsorpcyjnych mezoporowatych kompozytów węglowo-platynowych

Jedynak K., Wideł D., Surga W., Jóźwiak M. A, Choma J.

Inżynieria i Ochrona Środowiska

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2013

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T. 16, nr 2

179--192

PL

Opisano sposób otrzymywania jednorodnych mezoporowatych kompozytów węglowo-platynowych. W syntezie wykorzystano rezorcynol i formaldehyd jako prekursory węglowe oraz trójblokowy kopolimer EO101PO56EO101 jako miękką matrycę. Kwasu heksachloroplatynowego dodawano podczas syntezy kompozytu w takiej ilości, aby w finalnym materiale było ok. 1%, 5%, 10% lub 20% wag. metalicznej platyny. Otrzymane w ten sposób kompozytowe materiały węglowo-platynowe charakteryzują się dużą powierzchnią właściwą (od 560 do ponad 750 m2/g), dużą całkowitą objętością porów (od ok. 0,5 do ponad 0,7 cm3/g) oraz średnim wymiarem mezoporów ok. 7÷17 nm. Procentowy udział mezoporowatości jest znaczący i wynosi ok. 60÷75%. Wyniki badań szerokokątowego rozpraszania promieniowania rentgenowskiego XRD oraz analiza termograwimetryczna dowodzą obecności cząstek metalicznej platyny w matrycy węglowej. Ponadto badania TG wykazują, że tylko część platyny udało się wprowadzić do struktury węglowej (od ok. 1 do 4% wag. Pt), a także, iż badane materiały charakteryzują się znaczną termiczną trwałością w atmosferze powietrza. Zdjęcia ze skaningowej elektronowej mikroskopii (SEM) wskazują na znaczne zróżnicowanie kształtów i wymiarów cząstek platyny. Wymiary tych cząstek zmieniają się w dość szerokim przedziale od kilkudziesięciu nanometrów do kilku mikrometrów. Cząstki platyny są rozproszone w całej strukturze materiału kompozytowego, choć trudno uznać to rozproszenie za jednorodne. Warto podkreślić, że otrzymane kompozytowe materiały węglowe z cząstkami platyny o bardzo dobrych właściwościach adsorpcyjnych i kontrolowanej strukturze mikro- i mezoporów mogą być użyteczne w wybranych procesach adsorpcyjnych i katalitycznych.

EN

A relatively simple way of mesoporous carbon composites with platinum particles obtention was proposed. Soft templating in the acidic environment method was used. Also rezorcynol and formaldehyde were used as carbon precursors, triblock copolymer Lutrol F127 as the soft matrix and chloroplatinic acid as the source of metallic platinum particles. Four different, relatively small and large (1, 5, 10 and 20 wt.%) portions of platinum were embedded into the carbon matrix. Physicochemical properties of mesoporous carbon-platinum composites were investigated. Based on the low-temperature nitrogen adsorption isotherms total surface area, total pore volume, volume of micro and mesopores, exterior surface and the pore size distribution function (using the Kruk-Jaroniec-Sayari method - KJS) and average pore size of tested composites were determined. Wide-angle X-ray difraction (XRD) research allowed us to confirm the presence of platinum particles in the structure of carbon materials studied. SEM photos allowed to determine the morphology of these materials. However, thermogravimetric measurements provided an answer to the question of the thermal stability of mesoporous carbon-platinum composites and the platinum particle content in the carbon matrix. Nevertheless, the presence of nonporous platinum particles of a large mass deteriorates the adsorption properties of mesoporous carbon-platinum composites, the obtained carbon-platinum composite materials showed high specific surface areas (in the range of 560 to 700 m2/g) as well as large total pore volumes (in the range of 0.5 to 0.6 cm3/g), with the contribution of mesoporosity volume between 55-75%. Pore size distribution functions showed presence of micropores with 2 nm width and mesopores with width between 7÷17 nm. XRD and thermogravimetric measurements confirmed the presence of platinum particles in carbon composites. SEM photos indicate noticeable differences of platinum particles size and shape. It has been observed that both nanoparticles and microparticles of platinum are covering entire analyzed area, but it is hardly homogeneous dispersion. Well-developed porous structure of the carbon-platinum composites gives an opportunities for the application of those materials to specific adsorption, catalytic processes and especially in water treatment processes.