• Journal of the Korea Institute of Military Science and Technology
• /
• v.6 no.3
• /
• pp.74-85
• /
• 2003

NENA(nitratoethyl nitramine) compounds, especially BuNENA(N-butyl-N-(2-nitratoethyl)-nitramine), are of high interest to both rocket propulsion and military high explosives because of low sensitivity to many forms of stimuli, although they are less energetic than conventional nitrate ester plasticizers. One of advantages in using NENAs is that they provide higher impulse at any given flame temperature than conventional propellants do. BuNENA has better thermochemical characteristics(low melting point and low glass transition temperature), therefore has less tendency to crystallize out of matrices. BuNENA was successfully synthesized in a high yield by reaction of n-butyl aminoethanol and 98% nitric acid followed by dehydrogenation of salt mixture by $Ac_2$/$ZnCl_2$.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.20 no.5
• /
• pp.40-50
• /
• 2016

Energetic plasticizers containing explosophore groups such as $-NO_2$, $-ONO_2$, and $-N_3$ group are susceptible to impact, shock, heat, etc, finally deteriorating the insensitivity of PBXs. In this study, in an attempt to investigate the feasibility of replacing sensitive explosophore groups to fundamentally inactive but potentially (latent) energetic fluorine group which was known to have an exothermic thermite reaction with aluminum, nano-aluminum/fluorinated polyurethane binders were prepared by simultaneous polyurethane and catalyst-free azide-alkyne click reaction in the presence of nano-aluminum. Thermal characteristics of nano-aluminum/fluorinated polyurethane binders were monitored by using DSC with high pressure crucible pan.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.5 no.4
• /
• pp.49-56
• /
• 2002

For the purpose of the increase in the performance and thermal stability of PBX's, the mixed formal consisting of BDNPF, DNPBF and BDNBF were synthesized. In order to find out the optimal condition for the synthesis of energetic plasticizer, BDNPF, DNPBF and BDNBF, the synthetic procedures have been investigated. We synthesized DNP-OH and DNB-OH through oxidative nitration and controlled various composition of mixed formal by $H_{2}SO_{4}$ and s-trioxane to investigate optimal composition, and then characterized its thermo-physical properties.

• Journal of Korea Foresty Energy
• /
• v.17 no.1
• /
• pp.36-46
• /
• 1998

The aim of this study was to develop the noise and vibration damping wood-based composites by using viscoelastic polymer materials. Polyvinylchloride(PVC) was plasticized with 20-140 phr bis(2-ethylhexyl) phthalate(DOP) and the dynamic tensile mechanical properties were measured at 110Hz and approximate temperature range -100 to 150$^{\circ}$ using a Rheovibron Instrument. The PVC/DOP blends were shown to be compatible in all proportions, and both T(E”$_{max}$) and T(tan${\delta}_{max}$) shifted to the lower temperature side as the DOP content increased. The vibration damping properties of wood/polymer composites were measured using the Rheovibron instrument in a bending mode. The composite damping factor(tan ${\delta}_{c}$) of wood /PVC-DOP/wood sandwich structure correlated with the loss factor and that of the coated structure correlated with the loss modulus(E”) of the polymer layer. In addition, the sandwich structure was found to be more effective in damping than the coated structure. The logarithmic decrement (${\Delta}$c) curve of a sandwich structure, which was determined by the free-free flexural vibration method was similar in shape to the tan ${\delta}_{c}$ curve.

• Journal of Radiation Protection and Research
• /
• v.3 no.1
• /
• pp.23-28
• /
• 1978

In order to investigate corelation between contents of dioctylphthalate in polyvinylchloride blent dibutyl tin dilaulate with dibutyl tin maleate as stabilizer and the behaviors of radiation resistance as well as electrical conductivity on irradiated specimens, several observations were carried out. A characteristic peak observed in the range of $1,540-1,640cm^{-1}$ on infrared spectra shows such a sensitive response to radiation as the intensity decreases with increasing doses and that this tendency strongly depressed in the presence of plasticizer. It is seemingly attributed for origin of the peak to the existence of RCOO- ion resulting from dissociation of stabilizere, further the depressive effect of decreasing peak intensity influenced by radiation seems to be caused by resonance absorption in benzen ring being a consistituent of plasticizer. It is also suggestive to be use the peak behavior influenced by radiation as a criterion for the evaluation of radiation resistance of PVC. Further the results obtained from electrical conductivity measurement also exhibit reasonable characteristics explainable with views used for the interpretation of the peak behavior mentioned previousely.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.3 no.4
• /
• pp.31-37
• /
• 1999

Recently, the development of propellant trends toward minimum smoke signature, insensitivity and high performance. PSAN has been used as a oxidizer for less sensitive minimum smoke propellant. Unfortunately, it provides low performance to propellant. Energetic polymers such as GAP and PGN are frequently proposed for use in minimum smoke Propellants to overcome the energy Penalty imposed by using AN as the oxidizer. In this study the mechanical properties, glass transition temperature and viscosity of PGN and EPGN binder were investigated.

• Applied Chemistry for Engineering
• /
• v.30 no.2
• /
• pp.233-240
• /
• 2019

Molecular recognition technology has attracted considerable attention for improving the selectivity of a specific molecule by imprinting it on a polymer matrix. In this study, adsorption and release characteristics of chitosan based drug delivery films imprinted with sulindac (SLD) were investigated in terms of the plasticizer, temperature and pH and the results were also interpreted by the related mathematical models. The adsorption characteristics of target molecules on SLD-imprinted polymer films were better explained by the Freundlich and Sips equation than that of the Langmuir equation. The binding site energy distribution function was also useful for understanding the adsorption relationship between target molecules and polymer films. The drug release of SLD-imprinted polymer films followed the Fickian diffusion mechanism, whereas the drug release using artificial skin followed the non-Fickian diffusion behavior.

• Applied Chemistry for Engineering
• /
• v.9 no.1
• /
• pp.135-140
• /
• 1998

The constituents of deposits on paper machine and holes/spots in paper have been analyzed by a combination of analytical techniques, such as FTIR, Py-GC-MS, and EDS. FTIR spectroscopy was used prior to Py-GC-MS and EDS analysis, as a preliminary analysis. The analysis of organic components was carried out with a pyrolysis unit connected to a GC-MS, and inorganic components in ash were analyzed by SEM equipped with an EDS analyzer after pyrolysis at $590^{\circ}C$. The deposits on the dryer section were complex pitch, which was the mixture of the organic components of fatty acid ester and starch, and the inorganic components of talc, clay, and calcium carbonate. The complex pitch was estimated to come from the coated broke. We knew the deposits on the metering rod of sym-sizer were associated with the interaction of unstable alkyl keten dimer(AKD) and $CaCO_3$. The compositions of holes or spots varied considerably and were associated with chemical interaction within the system. The holes, spots, and blotches in the finished paper were PE and PP from pulp sources, complex pitch that were caused by the interaction of the different additives in the system, polymer such as flexible PVC that was used for the prop of palette, and hot melt as adhesives that came from the inadequate handling of broke. In addition, we identified that poly(caprolactam) which is used for forming fabrics or press felts, could be mixed with the raw materials by accident and results in streaks on coating.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.15 no.3
• /
• pp.169-174
• /
• 1995

To investigate the effects of nitrogen(N) fertilization levels on the dry matter(DM) yield, nutrition yield, and N efficiency of forages in mixed sward of alfalfa-grasses, a field experiment arranged by randomized complete block design with five treatments(0, 70, 140, 210 and 280kg N/ha) was conducted at Livestock Experiment Station in Suwon, September, 1990 to February, 1993. During two years, average DM yields of forage increased as N fertilization level was increased, but no significant difference was found between DM 10,266kg of N 210kgha and DM 10,845kg of N 280kgha. Crude protein and energy productivity of forages increased as N fertilization level was increased, and the increasing degree was highest between N 140kg and 210kg/ha fertilization. With increasing N fertilization, mineral contents tended to decrease in P and K/Ca+ Mg equivalent ratios, to increase in Mg, but not to be regular in the other elements. Efficiency of N was highest at N 210kg/ha fertilization, which produced DM 21.6kg, net energy lactation 129.3 MJ, starch equivalent 12.3kStE and total digestible nutrients 14.5kg per Ikg N.