Hydroxyl terminated polybutadien (HTPB RESIN) is a liquid hydrocarbon polyol that is commonly used in the preparation of solid composite propellants. Because of unsaturated nature of HTPB polymer, it has high potential for oxidative aging. In this paper, the change in the properties of two types of HTPB RESIN under thermal oxidative aging in the presence and absence of phenolic antioxidant have been investigated. For this purpose, two samples of RESIN have been stored at 60oC during four month under atmospheric pressure and the changes of the peroxide value, hydroxyl value, epoxy number, viscosity and molecular weight have been investigated. The results show that crosslinking of radical chains, increase of the molecular weight and hydroxyl functionality of HTPB are the most important oxidative events that occurred during oxidative aging.

Hydroxyl terminated polybutadiene (HTPB) is the most commonly used binder in composite solid propellants. However, due to its non-energetic characteristic, it is recognized as a dead weight in practice. Therefore, replacing HTPB with an energetic polymer is essential. In this research, nitrated hydroxyl terminated polybutadiene RESIN (NHTPB) with 12. 2% nitration rate, in combination with HTPB RESIN was used as binder. Thus, the HTPB propellant base formulation (HB) was prepared as a reference sample and its physical-mechanical properties, burning rate, and sensitivity were compared with two other cured formulations: the propellant formulation with binder ratio of 5% NHTPB and 95% HTPB (NH5) and the other with binder ratio of 10% NHTPB and 90% HTPB (NH 10). The results showed that, with increasing NHTPB to HTPB ratio from 5% to 10%, Young's modulus, burning rate, impact, and friction sensitivities were increased in comparison to reference propellant. In addition, the cross-linking density, hardness, and tension were decreased.

In this study, the efficiency of UASB reactor method for treatment of HTPB plant wastewater was investigated. For this purpose, a UASB reactor with a volume of 227 liters was used. The HTPB plant wastewater includes ethanol, oxygen peroxide, various compounds of HTPB RESIN and water. The UASB reactor was started up with the feed concentration of 500 mgcod/l. To make sure of the sludge granulizing process during the start-up period, various analyses such as TSS, VSS and methanogenic activity were carried out over sludge samples. These analyses indicated that the sludge was successfully granulated into the UASB reactor. Also, results of effluent analysis showed that treatment efficiency was progressively raised. Treatment efficiency was 78% at the end of start-up period. After stabilization of the treatment process, effect of feed concentration and liquid apparent velocity were evaluated. Results of the reactor experiments indicated that feed concentration of 10000 mgcod/l and apparent velocity of 1.3 m/h are the optimum conditions for treatment of HTPB plant wastewater. Under this condition, the removal efficiency of contaminants was 95%.

Hydroxyl-terminated polybutadiene (HTPB) has been widely used as a binder for energetic composites. This neutral binder contains 10 to 15% by weight of these compounds, which if energized, increase the energy content and maintain the physical and chemical properties of the original HTPB to a large extent. The binding of Nitro to the main chain of HTPB (nitration) is a good way to energize it. Nitration common methods, such as nitration with a mixture of acids, dinitrogen pentoxide, and nitromercuration-demercuration, have led to the destruction of the backbone of the polymer. In this research, Nitration with nitrile iodide reagent has been used for the functionalization of HTPB with nitro groups, in which the double bonds and the backbone of RESIN are not degraded. In order to maintain the unique physical and chemical properties of HTPB, nitration levels are limited to 10 to 15% of double bonds. The purpose of this research was to investigate the effect of HTPB RESIN structure and the ratio of reactants used on the HTPB nitration process. For this purpose, four samples of nitrated Hydroxyl-terminated polybutadiene (Nitro-HTPB) were synthesized from two different types of HTPB with different characteristics and using two different proportions of the reactants. Then, samples were characterized by FT-IR and 1HNMR tests, and parameters such as percentage of nitration, microstructure, and their rheological behavior were compared. The results showed that the nitration rate of the synthetic samples was influenced by the ratio of the reactant used and the percentage of trans-microstructure of the initial HTPB RESIN. Also, samples with higher nitration content have higher viscosity and less pot life. Considering all the parameters, it can be claimed that NHA1 RESIN with 12. 2% nitro content among synthesized RESINs (among 3. 1, 4. 1, 12. 2, and 17. 6%) has the potential to be used as a binder in energetic composites.

Epoxy RESINs (ER) are considered as one of the most important classes of thermosetting polymers and are extensively used in various applications. But they are very brittle, with poor resistance to crack propagation and have low impact strength. In the present work, a series of hydroxyl terminated polybutadiene (HTPB) was directly dispersed in the epoxy RESIN. Then, the dispersed phase was cross-linked by divinylbenzene (DVB) that was previously added to HTPB. Different content of DVB and HTPB are evaluated for effecting on the most of physico-chemical properties of the epoxy RESIN. The FTIR analysis evidenced the occurrence of a chemical reaction between HTPB and DVB and also ER which was led to improved compatibility. The DMTA analysis of samples indicated different Tg for HTPB/DVB and ER in the mixture and explaining the phase separation between rubber and matrix phases. On adding DVB the stress-at-break increased accompanied by an increase in the elongation-at-break value. Maximum impact strength is obtained by adding 20 phr of DVB and 5 phr HTPB. Finally, SEM analysis showed that modified rubber particles’ diameter is about 5 mm (corresponding to maximum of toughness).

Aging resulting in stabilization is one of the most important and advanced aspects of polymer chemistry. Solid propellants as polymer-based materials deal with aging process as well. This research work has evaluated Dynamic Mechanical Analysis (DMA) for characterization of composite propellant samples during an accelerated aging program. Although there are only a few reports in the open literature concerned with using DMA in aging studies they are not reported inside the country. In this method, the changes in storage module (E) and damping (tand) of the sample during the aging time versus temperature are investigated. Accelerated aging tests at 25, 45, 60, and 70°C were performed for the maximum 8000 h. Finally, we observed that damping efficiency decreases about 12% as a result of thermal aging. The resulted data may be used to determine the aging rate, service time and decomposition mechanism during the rocket storage.

Nitro functionalization of alkenes has particular importance in the field of energetic materials due to unsaturated nature and the ability to synthesize a wide range of C-nitro aliphatic compounds. Considering the importance of these compounds, the use of nitrile iodide as a mild, inexpensive and safe reagent to nitro functionalization of HTPB as an unsaturated prepolymer was studied in this paper. In order to optimization of the effective parameters on the synthesis of Nitro-HTPB, the proportional amounts of reactant, amount of solvent, temperature and reaction time were investigated and the effect of these parameters on the efficiency of nitro functionalized products was evaluated. It was observed that the kind and amount of solvent have a significant impact on the quality of product. In this regard, 24 hours of reaction time at room temperature were considered as optimal conditions. Finally, differential scanning calorimetry (DSC) method was used to study the effect of the amount of nitro group on the thermal behavior of the products. It was observed that by increasing the nitro group amount of products, thermal stability decreases and heat of decomposition increases.

Hydroxyl terminated polybutadiene (HTPB) is the most important and versatile binder used in the formulation of composite solid propellant. However, HTPB is an inert binder and immiscible with traditional energetic plasticizers. In this research, two types of energetic plasticizer, 2-ethylhexyl nitrate (2EHN) and 2-ethyl-2-buthyl-1, 3 dinitrate propane (EBDP), which have C /-ONO2 ratio greater than 4 are synthesized and characterized by FT-IR and 1H NMR. Performance of these compounds as energetic plasticizer have been investigated by measuring their heat of decomposition, heat of combustion, glass transition temperature and heat of formation. In addition, the compatibility of the selected plasticizers with HTPB, have been evaluated by calculation of Hansen solubility parameter and measurement of glass transition temperature (Tg) by differential scanning calorimeter (DSC). Low value of miscibility parameter (Δδ) and appearance of a single glass transition Tg is a reason for miscibility of the plasticizer in HTPB and formation a homogeneous binder/plasticizer system. Furthermore, the viscosity measurement of RESIN in different weight percent of plasticizer have shown that the equal mixture of two plasticizers provide the best results for process ability of RESIN.

Background and Objective: T3 RESIN uptake test indicates the availability of thyroxin binding globulin (TBG), which is the carrier of a large amount of T3 and T4 in blood. We aimed to study the relationship between serum T3 RESIN Uptake and serum lipids profile.Material and Methods: The participants aged 14.80±38.29 were both males (59; 29.5%) and females (141; 70.5 %). T3 RESIN Uptake was measured by Immunoassay method and serum lipid profile components (cholesterol, triglycerides, HDL-C, LDL-C, and VLDL) were measured by the kit. Results: Significant negative correlation was observed between serum T3 RESIN Uptake and cholesterol, triglycerides and LDL-C (P£0.05), but that was not the case for HDL-C and VLDL.Conclusion: Serum T3 RESIN Uptake can be evaluated to assess the risk factors related to cardiovascular disorders.