Thermal ageing of hydroxyl-terminated polybutadiene propellant binders was carried out at various temperatures between 50 and 100-degrees-C. The changes caused by this treatment in properties such as melt viscosity, functional end-groups, molecular weight, tensile strength, elastic modulus and ultimate elongation were examined. The viscosity and average molecular weight increased with the ageing temperature and ageing period. A decrease in ultimate elongation and an increase in elastic modulus were observed. Tensile strength of the matrices prepared by curing hydroxyl-terminated polybutadiene with isophorone diisocyanate did not change. Lifetime for usability was predicted from the application of the Arrhenius equation to be 7 years.


Effects of Zinc Borate on the Flame Retardancy Performance of Aluminum Diethylphosphinate in Polyamide-6 and its Composites
Polat, Özlem; Kaynak, Cevdet (Carl Hanser Verlag, 2019-03-01)
In this study, the flame retardancy contribution of zinc borate when used together with a traditional flame retardant (aluminum diethylphosphinate compound) was investigated for neat polyamide-6 and for 15 wt% short glass fiber reinforced composite. Melt mixing with twin-screw extrusion was the compounding method while injection and compression molding were the shaping methods of specimens. Three different flammability tests (limiting oxygen index, UL-94 vertical burning, mass loss calorimetry) indicated th...
Effect of a carbon black surface treatment on the microwave properties of poly(ethylene terephthalate)/carbon black composites
Koysuren, Ozcan; Yesil, Sertan; Bayram, Göknur; Secmen, Mustafa; Aydın Çivi, Hatice Özlem (Wiley, 2008-07-05)
A surface treatment was applied to carbon black to improve the electrical and microwave properties of poly(ethylene terephthalate) (PET)-based composites. Three different formamide solutions with 1, 2, and 3 wt % concentrations were prepared to modify the surface chemistry of carbon black. Microwave properties such as the absorption loss, return loss, insertion loss, and dielectric constant were measured in the frequency range of 812 GHz (X-band range). Composites containing formamide-treated carbon black e...
Effects of micro-nano titania contents and maleic anhydride compatibilization on the mechanical performance of polylactide
CAN, ULAŞ; Kaynak, Cevdet (Wiley, 2020-02-01)
The first aim of this study was to compare influences of various contents of the micro- (200 nm) and nano (50 nm)-sized titania (TiO2) particles especially on the mechanical performance of the polylactide (PLA) biopolymer. Micro- and nano-composites were prepared by twin-screw extruder melt mixing, while the specimens were shaped by compression molding. Scanning electron microscope analyses and mechanical tests revealed that due to the most efficient uniform distribution in the matrix, the best improvements...
Influence of Zinc Oxide on Thermoplastic Elastomer-Based Composites: Synthesis, Processing, Structural, and Thermal Characterization
ÇELEBİ, HANDE; Bayram, Göknur; DOĞAN, AYDIN (Wiley, 2016-08-01)
It was aimed to investigate how thermal conductivity and stability properties of synthesized thermoplastic elastomers were influenced by zinc oxide (ZnO) additives which differed in size and surface treatment. ZnO particles were prepared by the homogeneous precipitation method by mixing aqueous solutions of hexamethylenetetramine (HMT) and zinc nitrate. The obtained particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Poly(v...
Characteristics of Impact Modified Polystyrene/Organoclay Nanocomposites
Yeniova, Canan Esma; Yılmazer, Ülkü (Wiley, 2010-11-01)
The poor impact resistance of Polystyrene (PS) was enhanced by the addition of elastomeric material, SEBS-g-MA. To prevent the reduction in strength and stiffness, organoclay Cloisite (R) 25A was used as filler and introduced into the matrix by a corotating twin screw extruder. Throughout the study, the clay content was kept at 2 wt%, whereas the content of SEBS-g-MA was varied between 5 and 40 wt%. It was found that Cloisite (R) 25A displays well dispersion in the ternary nanocomposites and the degree of d...
Citation Formats
A. AKBAS and S. AKSOY, “EFFECTS OF THERMAL AGING ON THE PROPERTIES AND LIFETIME PREDICTION OF HYDROXYL-TERMINATED POLYBUTADIENE,” POLYMER, pp. 2568–2572, 1994, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/64855.