Curing characteristics of glycidyl azide polymer-based binders

Kasikci, H
Pekel, F
Özkar, Saim
The curing of a glycidyl azide polymer (GAP) with a triisocyanate, Desmodur N-100, was followed by measuring the hardness and viscosity. The thermal behavior of the cured samples were investigated by a differential scanning calorimeter (DSC) and thermal gravimetric analysis (TGA). Curing causes an increase in the glass transition temperature of GAP. The T-g of gumstocks also increases with an increasing NCO/OH ratio while the decomposition temperature remains practically unchanged. The ultimate hardness of the cured samples increases with an increasing NCO/OH ratio. The binder with a NCO/OH ratio of 0.8 was found to provide the most suitable thermal and physical characteristics for composite propellant applications. The increase in the glass transition temperature of gumstocks upon curing can be compensated by using a 1:1 mixture of bis-2,2-dinitropropyl acetal and formal as the plasticizer. The T-g value of gumstocks can be decreased to -46.7 degreesC by adding 25% b.w. of a plasticizer which does not have any significant effect on the decomposition properties of the gumstocks. Furthermore, a remarkable decrease in the ultimate hardness of the gumstocks is achieved upon addition of a plasticizer, while the curing time remains almost unaffected. The addition of dibuthyltin dilaurate as a catalyst reduces the curing time of the gumstocks from 3 weeks to 5-6 days at 60 degreesC. Use of the curing catalyst also results in the hardening of the gumstocks. The decomposition properties of the gumstocks remain practically unchanged while a noticeable increase is observed in the glass transition temperature with an increasing concentration of the catalyst. This can also be compensated by a reverse effect of the plasticizer. The gel time, an important parameter which determines the pot life of a propellant material, can be measured by monitoring the viscosity of the mixture, which shows a sharp increase when gelation starts. The addition of a curing catalyst shortens the gel time remarkably. (C) 2001 John Wiley & Sons, Inc.


Kinetics of polyurethane formation between glycidyl azide polymer and a triisocyanate
Keskin, S; Özkar, Saim (Wiley, 2001-07-25)
Kinetics of the polyurethane formation between glycidyl azide polymer (GAP) and a polyisocyanate, Desmodur N-100, were studied in the bulk state by using quantitative FTIR spectroscopy. The reaction was followed by monitoring the change in intensity of the absorption band at 2270 cm-l for NCO stretching in the IR spectrum, and was shown to obey second-order kinetics up to 50% conversion. The activation parameters were obtained from the evaluation of kinetic data at different temperatures in the range of 50-...
Conducting polymer composites: Polypyrrole and poly(vinyl chloride vinyl acetate) copolymer
Balci, N; Bayramli, E; Toppare, Levent Kamil (Wiley, 1997-04-25)
Composites of a polypyrrole (PPy) and poly(vinyl chloride-vinyl acetate) copolymer (PVC-PVA) were prepared both chemically and electrochemically. An insulating polymer was retained in the blend and the thermal stability of the polymer was enhanced by polymerizing pyrrole into the host matrix in both cases. The composites prepared electrochemically gave the best results in terms of conductivity and air stability. (C) 1997 John Wiley & Sons, Inc.
Preparation and Characterization of Polypropylene/Serpentine Composites
Tan, Semra; Tincer, İsmail Teoman (Wiley, 2011-07-15)
Composites of serpentine and polypropylene (PP) were prepared by twin-screw extrusion. Serpentine was collected as rocks from the Ankara-Beynam region and ground into powder with an average particle size of about 3 mu m for composite production. Both as-received (rock) and powdered serpentine were characterized. A silane coupling agent (SCA), gamma-aminopropyl triethoxy silane, was used for the surface treatment of serpentine. Mechanical properties of the composites were measured in terms of impact strength...
Thermal characterization of glycidyl azide polymer (GAP) and GAP-based binders for composite propellants
Selim, K; Özkar, Saim; Yılmaz, Levent (Wiley, 2000-07-18)
Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were used to investigate the thermal behavior of glycidyl azide polymer (GAP) and GAP-based binders, which are of potential interest for the development of high-performance energetic propellants. The glass transition temperature (T-g) and decomposition temperature (T-d) of pure GAP were found to be -45 and 242 degrees C, respectively. The energy released during decomposition (Delta H-d) was measured as 485 cal/g. The effect of th...
Synthesis and characterization of multi-hollow opaque polymer pigments
Asmaoglu, Serdar; Gündüz, Güngör; MAVİŞ, BORA; Colak, Uner (Wiley, 2016-08-05)
A new generation multihollow opaque polymer pigment was synthesized by suspension polymerization of water-in-oil-in-water emulsion method, where methyl methacrylate and ethylene glycol dimethacrylate monomer mixture was used as oil phase. The effects of surfactant and cosurfactant composition in terms of hydrophilic/lipophilic balance on the stability of the water-in-oil emulsion and the size of water droplets were studied. Low droplet sizes and the optimum stability were obtained with Span 80&Tween 80 surf...
Citation Formats
H. Kasikci, F. Pekel, and S. Özkar, “Curing characteristics of glycidyl azide polymer-based binders,” JOURNAL OF APPLIED POLYMER SCIENCE, pp. 65–70, 2001, Accessed: 00, 2020. [Online]. Available: