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A Versatile Fuel Binder for Composite Solid Propellant

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Nguyễn Gia Hào

Academic year: 2023

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The assignment of the various resonances in this region was based on a report by Haas (1985). The resonance at δ 58.50 is assigned to the methylene carbon of the cis-1,4-hydroxyl structure, while the other resonances at δ 63.67 and 65.06 are assigned to the methylene carbon of the trans-1,4-hydroxyl and vinyl-1,2-hydroxyl structures, respectively. Further, each of the three signals would split into four peaks (ie the signal for HA is split into two by the HB and again into two by the HX proton).

Figure 1.  13 C{ 1 H} NMR (CDCl 3 , 200 MHz) spectrum of free radical HTPB prepolymer
Figure 1. 13 C{ 1 H} NMR (CDCl 3 , 200 MHz) spectrum of free radical HTPB prepolymer

Rheology of HTPB prepolymer: Temperature modelling

The number average molecular weight of the polymer could be estimated by 1H qNMR end group analysis. The viscosity dependence on temperature can also be fitted with a Power Law model of the form�����.

Figure 11.  Molecular structure of (a) free radical HTPB, and (b) anionic HTPB prepolymer   (Krasol LBH-3000)
Figure 11. Molecular structure of (a) free radical HTPB, and (b) anionic HTPB prepolymer (Krasol LBH-3000)

Chemo-rheology of PU-I, PU-II and PU-IIp: Temperature and time modelling

The viscosity of the curing PU system is determined by two factors: (a) the degree of curing, and (b) the temperature. The fact that temperature changes the viscosity of the slurry means that special attention must be paid to kinetic and thermodynamic factors.

Figure 12.  Plots of �������t�� �� vs. temperature for prepolymers (HTPB).
Figure 12. Plots of �������t�� �� vs. temperature for prepolymers (HTPB).

Thermo-oxidative degradation of prepolymers (HTPB) and PU-II

The influence of different heating rates (β) on the thermo-oxidative behavior of free radical HTPB prepolymer is illustrated in Fig.18. The insert in Fig.18 shows the influence of different heating rates (�) on the thermo-oxidative behavior of PU-II. We used the Coats-Redfern method (CR) i.e. 14) to investigate the thermal degradation mechanism of the prepolymers and PU-II.

Figure 15.  Pseodplasticity index (PI) of PU-IIp as a function of cure time at different temperatures
Figure 15. Pseodplasticity index (PI) of PU-IIp as a function of cure time at different temperatures

HTPB polyurethanes: Stress-strain properties

Conclusion

Author details

Acknowledgement

Investigation of exothermic oxidation of acrylonitrile-butadiene-styrene (ABS) resin powder with application to ABS Processing Safety. Polymers, Vol. 2, p. 1991). The effect of solvent on the microstructure, nature of hydroxyl end groups, and kinetics of polymerization reaction in the synthesis of hydroxy-terminated polybutadiene.

Synthesis of a New Sorbent Based on Grafted PUF for the Application in the Solid Phase

Introduction

Naphthalene is used in preconcentration procedures due to its ability to extract or form a complex with organic species (Fathi et al., 2011). Various reagents have been incorporated into polystyrene-divinylbenzene to form chelating resins for use in preconcentration procedures (Lemos et al., 2006a).

Experimental 1. Apparatus

  • Reagents
  • Synthesis of the reagent Me-BTAP
  • Synthesis of the sorbent
  • Procedure for preconcentration

The reagents 2,4-toluene diisocyanate (Aldrich), tin(II)-2-ethylhexanoate (Aldrich), dimethylamino-1-propanol (Aldrich), polyethylene glycol (Aldrich) and silicone oil AP 100 (Aldrich) were used in the synthesis of the sorbent. The synthesis of the reagent 2-[2'-(6-methyl-benzothiazolylazo)]-4-aminophenol (Me-BTAP) was performed as described previously (Lemos et al., 2006a).

Table 1. Procedures involving grafted PUF applied in the preconcentration of chemical species by  spectrophotometry
Table 1. Procedures involving grafted PUF applied in the preconcentration of chemical species by spectrophotometry

Results and discussion

  • Characterization of the sorbent
  • Effect of pH
  • Type and concentration of the eluent
  • Flow rate of solutions
  • Preconcentration time
  • Lifetime of minicolumn
  • Analytical characteristics
  • Application of the proposed procedure

The eluent transported Cd(II) or Pb(II) to the nebulizer of the flame atomic absorption spectrometer. Characteristics of the preconcentration system for the determination of cadmium and lead (A, absorbance and C, metal concentration, g L-1).

Figure 2. Infrared spectrum of PUF-Me-BTAP.
Figure 2. Infrared spectrum of PUF-Me-BTAP.

Fast, Selective Removal and Determination of Total Bismuth (III) and (V) in Water by Procaine

Experimental

  • Reagents and materials
  • General batch procedures
  • Analytical applications
  • Retention profile of bismuth (III) from the aqueous solution onto PUFs Bismuth (ІІІ) forms an orange – yellow colored tetraiodobismuthate(III) complex, [BiI 4 ] - [32]
  • Kinetic behavior of bismuth (ІІІ) sorption onto PQ + .Cl - -TOA loaded PUFs The influence of shaking time (0 __ 60 min) on the uptake of bismuth (ІІІ) from the aqueous
  • Thermodynamic characteristics of bismuth (ІІІ) retention onto plasticized PQ + .Cl - loaded PUFs

Commercial white PUF sheets were cut into cubes (10–15 mm), washed, treated and dried. Reagent PQ+.Cl- (1.0% w/v) was dissolved in water, shaken with PUF cubes in the presence of TOA (1% v/v) with effective mixing for 30 min, pressed and finally dried as reported [21]. The sample solution was then passed through a PQ+.Cl- impregnated PUFs g) packed column (10 cm x 1.0 cm i.d.) at 5 ml min.-1. The retained bismuth(III) species were then recovered and analyzed as described above.

Figure 2.  Effect of pH on the sorption percentage of bismuth (III) from aqueous solutions containing KI  (10 % m/v) - H 2 SO 4  (2.0 mol L -1 ) onto PQ +  .Cl -  immobilized PUFs (0.1 ± 0.002 g) at 25 ± 0.1 0 C
Figure 2. Effect of pH on the sorption percentage of bismuth (III) from aqueous solutions containing KI (10 % m/v) - H 2 SO 4 (2.0 mol L -1 ) onto PQ + .Cl - immobilized PUFs (0.1 ± 0.002 g) at 25 ± 0.1 0 C

Time, min

The results revealed significant retention of bismuth (III) on PQ+ .Cl- charged PUFs compared to other onium cations. Thus, the retention profile of bismuth (III) over a wide range of equilibrium concentrations of bismuth (III) ions on PQ+ .Cl-filled PUFs sorbent from aqueous KI (10% w/v)-H2SO4 (1.0 mol L-1) solutions was investigated. The amount of [BiI4]– retained on the PUFs at low or moderate bismuth(III) concentration varied linearly with the amount of bismuth(III) remaining in the aqueous test solution (Fig. 10). The equilibrium was only approached from the direction of [BiI4]-species-rich aqueous phase 9]p.

Figure 9.  Vant - Hoff plot of log K d  vs. 1000/T (K -1 ) of bismuth (ІІІ) retention from aqueous media  containing KI (10 % m/v) - H 2 SO 4  (0.5 mol L -1 ) onto PQ +  .Cl -  loaded PUFs
Figure 9. Vant - Hoff plot of log K d vs. 1000/T (K -1 ) of bismuth (ІІІ) retention from aqueous media containing KI (10 % m/v) - H 2 SO 4 (0.5 mol L -1 ) onto PQ + .Cl - loaded PUFs

Bismuth, µg mL -1

Chromatographic behavior of bismuth (ІІІ) sorption

The proposed PUF-packed columns were also tested for the collection and recovery of bismuth (V) species (< 5 μg L-1) from aqueous solutions after reduction to bismuth (ІІІ). It was found that the reduction of bismuth (V) to bismuth (ІІІ) is fast, easy and also forms a stable species [BiI4]. The aqueous solution of bismuth (III) and (V) was first analyzed according to the procedure described for bismuth (V).

Figure 13.  Dubinin-Radushkevich (D-R) sorption of bismuth (ІІІ) extraction from aqueous solution onto  PQ+.Cl -  loaded PUFs at the optimum conditions
Figure 13. Dubinin-Radushkevich (D-R) sorption of bismuth (ІІІ) extraction from aqueous solution onto PQ+.Cl - loaded PUFs at the optimum conditions

Analytical performance of the immobilized PUFs packed column

Volume of eluting agent

The sensitivity factor (ratio of the slope of preconcentrated samples to that obtained without preconcentration) was 33.3. n= 5) confirming the accuracy of the method. The figure of merit of the developed method compared satisfactorily with reported methods e.g. ICP-OES [45], spectrophotometric [47] and electrochemical [49 -51] (Table 5) in water confirming the sensitivity and applicability of the proposed method.

Interference study

The LOD of the developed method is much better than direct measurement by ICP–OES (5.0 μg ml-1). The LOD of the method can be improved to lower values ​​by prior pre-concentration of bismuth(III) species from large sample volumes of water (>1.0 L).

Analytical applications

Thus, we can conclude that the method could be used for the separation and/or determination of bismuth (III) and bismuth (V) after reduction of the latter to trivalence. Different concentrations of bismuth (III) were also added to the tested wastewater samples and analyzed (Table 6). The LOD of the method is quite close to the concentration of bismuth species reported in seawater.

3.8. Figure of merits of the PQ + .Cl -  immobilize PUFs packed column
3.8. Figure of merits of the PQ + .Cl - immobilize PUFs packed column

Polyurethane Grouting Technologies

PU grouting resin types

In the case of OMR material, the mixing of the components plays an important role in the grouting process. The curing process, after mixing and injecting the PU mixture into the stone mass, takes from several minutes up to a few hours, depending on the type of joint resin used. It presents further practical results of the authors obtained through their long-term experimental research, design work and application of PU.

Grouting equipment

Grouting technology

During the injection of grouting material into the rock mass, grouting elements are used. These are technically designed to transfer the pressure of the joint material, preventing backflow of the material from the well. The grout pump sucks both components of the grout resin from separate tanks or the components flow by gravity.

Figure 1. Two component electric grouting pump DV 97.
Figure 1. Two component electric grouting pump DV 97.

Behavior of PUR resin in the grouted environment

In the case of joints with reshaping of the rock environment, the so-called bracket occurs, which is basically a hydraulic fracture of the rock well known from the exploitation of oil and gas. Due to the high hydraulic pressure of the grouting medium in the ground, a spatial network of cracks is formed, which are then filled with grouting media. The length and width of the cracks depends on the pressure of the applied resin, the rate of penetration and the amount of joint resin.

Properties of grouted soil, rock and building material

  • Structure and texture of geocomposites
  • Determination of mechanical properties of PUR-geocomposites 1. Preparation of samples and testing specimens

According to the order of building units According to the character of the penetration of the binder into the rock. The cross section of the geocomposite body showed obvious macroscopic zonal heterogeneity of the material (Fig. 13b). A larger proportion of rock grains (higher volumetric weight) positively affects the strength of the geocomposite.

Table 3 below presents a simple classification system for description of structure and texture  of PU geocomposites according to various criteria
Table 3 below presents a simple classification system for description of structure and texture of PU geocomposites according to various criteria

Examples of practical applications of PU grouting

  • Reconstruction of Retaining Wall (Prague - Horni Pocernice, Czech Republic)
  • Hatarmenti water-gate (Zagyva River, Hungary) Task
  • Elimination of contaminated water outflows from the uranium deposit (Rozna, Czech Republic)
  • Sealing grouting of sewage collector (Pilsen, Czech Republic) Task
  • Securing of excavation of underground utility tunnel (Ostrava, Czech Republic)
  • Repair of cracks in the concrete of highway bridge (Belotin, Czech Republic) Task
  • Lock at the Danube River (Gabcikovo, Slovakia) Task
  • Repair of metro railway (Budapest, Hungary) Task

The impression of the 1st tube was followed by the immediate start of the grouting work. Grouting material in the vicinity of the water gate (photo of the control excavation after 10 years). The effectiveness of the joint works was proven by monitoring the ground water table level.

Figure 17.  Anchoring works
Figure 17. Anchoring works

Conclusion

PU grouting is performed with the aim of improving the physical and mechanical properties of rock, soil or building material in the construction. The project was supported by the Ministry of Trade and Industry of the Czech Republic under the Impulse program no. In addition, this work also contains data collected within the project of the Institute of Clean Technologies for Mining and Utilization of Raw Materials for Energy Use, reg.

On the Use of Polyurethane Foam Paddings to Improve Passive Safety in

Crashworthiness Applications

  • Polyurethane foam as an energy absorbing material
  • Crashworthiness efficiency of polyurethane foam
    • Numerical modelling
  • Results and discussion
    • Load distribution
    • Kinetic energy
    • Maximum acceleration
    • Energy absorption
  • Conclusions
  • References

The most defining feature is the part of the bumper that collides with the vehicle's side door, i.e. the deformable aluminum honeycomb blocks. A sudden increase in the kinetic energy can be observed for≈3 ms for the collision test without padding. This corresponds to the moment at which the impact structure begins contact with the door of the vehicle.

Figure 1. Stress-strain compressive behaviour of rigid polyurethane foam as obtained by [45].
Figure 1. Stress-strain compressive behaviour of rigid polyurethane foam as obtained by [45].

Polyurethane Trickling Filter in Combination with Anaerobic Hybrid Reactor for Treatment

Materials and methods 1. Tomato wastewater industry

  • Anaerobic hybrid (AH) reactor
  • Polyurethane trickling filter (PTF) reactor
  • Operating conditions
  • Analytical methods
  • Scanning electron microscope (SEM)
  • Efficiency of AH reactor as a pretreatment of tomato wastewater industry Figs 2a, b and c show the effect of HRT on the percentage reduction of COD fractions (COD
  • Polyurethane trickling filter (PTF) as a post-treatment system
  • Profile of polyurethane trickling filter (PTF) reactor
  • Efficiency of the combined system (AH+PTF) treating tomato industry wastewater at different OLRs and HRTs
  • Scanning electronic microscope (SEM) observation

The system delivered an effluent quality of 80 mg/l for COD and 30 mg/l for TSS. a) The efficiency of PTF for removing COD total at different OLRs; (b). Polyurethane trickle filter in combination with anaerobic hybrid reactor for wastewater treatment of the tomato industry 367. a) The efficiency of PTF for the removal of TSS different OLRs; (b). The efficiency of PTF for VSS removal in different OLRs. a) The efficiency of PTF for removing COD total at different OLRs; (b).

Figure 1.  PTF module coupled with AH reactor for treatment of tomato industry wastewater
Figure 1. PTF module coupled with AH reactor for treatment of tomato industry wastewater

Conclusions

Polyurethane trickling filter in combination with anaerobic hybrid reactor for the treatment of wastewater from the tomato industry 377 Dissolved oxygen: DO. Treatment of fruit juice industry wastewater in a two-stage anaerobic hybrid (AH) reactor followed by sequencing batch reactor (SBR). Treatment of a combined dairy and domestic wastewater in an up-flow anaerobic sludge blanket (UASB) reactor followed by activated sludge (AS system).

Polyurethane as an Isolation for Covered Conductors

The current usage of covered conductors in the middle to high voltage networks

  • Covered conductors
  • The use of covered conductors
  • High voltage

Covered conductors are conductors with insulation made of two dielectrics: the first is the insulating sheath and the second is air. The most widely used structure of covered conductors consists of the core made of hard, compact aluminum alloy and a waterproof/waterproof sheath made of a cross-linked polyethylene (XLPE). Due to the outer sheath, the covered conductors are not as vulnerable when they touch each other or come into contact with tree branches.

Using covered conductors at the highest voltage levels

  • The electric field: Cylinder of charge
  • Double-layer single-wire cable
  • Polarized conductors and the electric field intensity

This force is proportional to the electric charge q and a vector quantity that determines the state of space. The maximum value of the electric field strength is obtained on the surface of the inner cylinder. It is expected to be significantly lower than the dielectric strength, and the reason is that the majority of the electric field is displaced into a poorer dielectric - a surrounding that is also larger (the length of the array of insulating disks).

Figure 1.  Electric field intensity E(r) of an isolated cylindrical Gaussian surface
Figure 1. Electric field intensity E(r) of an isolated cylindrical Gaussian surface

The mechanics of the PUAC 2150/490/65 power line

  • Electromagnetic radiation
  • Evaluation of electromagnetic fields in the Slovenian legislation
  • Electric field intensity in the vicinity of an overhead power line

We calculated the intensity of the electric field at several points in the space around the conductor. We obtain the effective value of the electric field intensity by summing the entire period. We noted the highest value of electric field intensity at each time point of a period.

Figure 12. Electric field of a line charge
Figure 12. Electric field of a line charge

The calculation of the electric field intensity with the finite element method

  • Calculation of the electric field intensity at the edge of the insulation of the conductor
  • Calculation of the electric field intensity perpendicular to the conductor As a result, a figure is shown that depicts the calculation of the effective value of the electric

Electric field strength perpendicular to the bisector of space at the point of maximum descent. Calculation of the intensity of the electric field at the edge of the insulation of the conductor. We have calculated the potential coefficients of capacity (the inverse value of the matrix of potential coefficients), based on the geometry (arrangement of conductors and insulation on them).

Figure 19. The electrical field intensity perpendicular to the bisector of the span in the point of the  greatest sag
Figure 19. The electrical field intensity perpendicular to the bisector of the span in the point of the greatest sag

Conclusion

One of the major problems is the abandonment of the 220 kV voltage level in the transmission network. The designers are thinking about preserving 220 kV power line platforms and transitioning to 400 kV conductors. We also calculated the intensity of the electric field perpendicular to the axis of the overhead conductor at the point of greatest deflection.

Bio-Based Polyurethanes

Igor Tičar, Oszkar Biro, Kurt Preis, Uporaba 2D in 3D metod končnih elementov v elektromagnetnih raziskavah, Tretja konferenca elektroenergetikov Slovenije, Nova Gorica, 3-5. junij 1997. Stane Vižintin, Tadeja Babnik, Franc Jakl: Možnost uporabe sodobnih generacij tehnologij nadzemnih vodnikov v novih 400 kVitulinih jubljana, januar 2007. Vpliv elektromagnetne regulacije Vpliv novega zakona o elektromagnetnem sevanju na parametre daljnovodov 110 in 400 kV.

Seed Oil Based Polyurethanes: An Insight

  • SO based diols
  • PU from SO FAD
    • PU as coatings
    • PU as hybrids
    • PU as composites
  • SO based triol
  • PU from SO FAT
    • PU as coatings
    • PU as hybrids
    • PU as composites
  • SO based polyols
    • PU foams from SO FAP
    • PU foams from SO based FAD epoxies
  • SO based polymers for PU production
  • Summary

The properties of PU obtained from SO derivatives thus depend on a number of factors, such as (i) the type, composition and distribution of fatty acid residues in the triglyceride component, (ii) the number, distribution, location of hydroxyl (in the middle or closer to the end of the triglyceride chain) and the level of unsaturation in the polyol triglyceride or dichain structure of the polyol triglyceride type and (di, ester and dichain structure of the polyol triglyceride chain) used ocyanates and ( iv) the urethane content of the final PU [5‐8]. The properties of PU thus also depend on the content of EANC and DC, i.e. the number and position of hydroxyl groups. The properties of PU thus also depend on the content of EANC and DC, i.e. the number and position of hydroxyl groups.

Figure 1. SO derivatives used in the production of PU (a) polyol, (b) triol, (c) fatty amide triol, (d) fatty  amide diol, (e) monoglyceride, (f) polyesteramide, (g) polyetheramide, and (h) alkyd
Figure 1. SO derivatives used in the production of PU (a) polyol, (b) triol, (c) fatty amide triol, (d) fatty amide diol, (e) monoglyceride, (f) polyesteramide, (g) polyetheramide, and (h) alkyd

Hình ảnh

Figure 6.  1 H/ 13 C HMQC spectra of free radical HTPB prepolymer: carbon bearing hydroxyl end group  region
Figure 5. 1 H/ 13 C HMQC spectra of free radical HTPB prepolymer: olefinic region.
Figure 5. 1 H/ 13 C HMQC spectra of free radical HTPB prepolymer: olefinic region.
Table 6. Values of viscosity (� � � and rate constants�� � � for various PU systems.
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