• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.23-28
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• 2017

Pyrolysis characteristics of waste plastic films were investigated by using a thermogravimetric analysis and pyrolyzer-gas chromatography/mass spectrometry. Thermogravimetric analysis results revealed that the pyrolysis of waste plastic films can be divided into two distinct reactions; (1) the decomposition reaction of starch at between 200 and $370^{\circ}C$ and (2) that of other plastic polymers such as PS, PP, PE at between 370 and $510^{\circ}C$. The kinetic analysis results obtained by using the revised Ozawa method indicated that the apparent activation energy of the pyrolysis reaction of waste plastic films was also changed dramatically according to the different decomposition reactions of two major waste plastic film components. Py-GC/MS results also revealed that the typical pyrolyzates of each polymer in waste plastic films were levoglucosan (starch), terephthalic acid (PET), styrene monomer, dimer, and trimer (PS), methylated alkenes (PP), and triplet peaks (PE) composed of alkadiene/alkene/alkane. The phthalate, used as a polymer additive, was also detected on the pyrogram of waste plastic films mixture.

• Polymer(Korea)
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• v.24 no.3
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• pp.399-406
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• 2000

A thermotropic liquid crystalline polymer (TLCP) containing a flexible spacer was synthesized from hydroquinone, p-hydrofybenzoic acid, and 1,6-dibromohexane. Intercalation of TLCP in layered clays is accomplished by heating the polymer with dodecyl ammonium-montmorillonite (C$_{12}$-MMT) above melt transition temperature (T$_{m}$). Liquid crystallinity of the TLCP/C$_{12}$-MMT hybrid was not observed when $C_{12}$-MMT content was above 1 wt%. Some of the $C_{12}$-MMTs in TLCP were highly dispersed in a nanometer scale, but some of them were agglomerated. Thermal and morphological properties of the nanocomposites were examined by differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA), polarized optical microscope, and electron microscopes (SEM and TEM). TEM).

• Applied Chemistry for Engineering
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• v.31 no.3
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• pp.328-333
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• 2020

In this study, blended feedstock derived pyrolyzed fuel oil (PFO) and coal-tar was prepared to produce a pitch by thermal polymerization reaction for manufacturing artificial graphite materials. The aromaticity value of 0.355 and 0.818 was obtained for PFO and coal-tar, respectively. In addition, PFO and coal-tar exhibited the difference tendency of weight loss curve for thermogravimetric analysis, which is related to the structural stability depending on the aromaticity and functional groups. The production characteristics confirmed that the pitch derived PFO showed lower production yield and higher softening point than that using blended feedstock. In particular, when comparing P360 (138.5 ℃) and B420 (141.4 ℃) having similar softening points, the production yields of both pitches exhibited 29.89 and 49.03 wt%, respectively. This is mainly due to the blending of PFO and coal-tar having high pitch polymerization reactivity including a large amount of alkyl groups and coal-tar having high thermal stability. This phenomenon indicated that the increased production yield is because of a synergic effect of both the high reactivity of PFO and thermal stability of coal-tar.

• Polymer(Korea)
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• v.25 no.5
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• pp.625-634
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• 2001

New polymeric photostabilizers containing hindered amine light stabilizer (HALS) were prepared by the reaction of liquid polyisoprene rubber grafted maleic anhydride (MAH) and 2,2,5,6-tetramethyl-4-piperidinol (TMPO). Their chemical composition and physical properties were characterized by titration, GPC and TGA analysis. The effects of polymeric HALS on the photooxidation of the styrene-butadiene rubber were studied from the UV, IR spectral changes, and photo-crosslinking was examined by the measurement of the insoluble fraction. The photooxidation of SBR upon irradiation was inhibited by addition of the new polymeric HALS. The extraction resistance of new polymeric photostabilizer was much better than that of the low molecular weight compound which is prepared by the reaction of MAH and TMPO. The new polymeric HALS ate fairly compatible with the SBR.

• Fire Science and Engineering
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• v.13 no.2
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• pp.26-32
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• 1999

We had investigated combustion pro야$\pi$ies of rice bran dusts. Decomposition of rice bran d dusts with temperature were investigated using DSC and the weight loss according to t temperature using TGA in order to find the thermal hazard of rice bran dusts, and the p properties of dust explosion in variation of their dust with the same particle size. Using H Hartman's dust explosion apparatus which estimate dust explosion by electric ignition after m making dust disperse by compressed air, dust explosion experiments have been conducted by v varying concen$\sigma$ation and size of rice br뻐 dust. According to the results for thermodynamic stability of rice bran dust, there are little change of initiation temperature of heat generation 때d heating value for used particle size. But i initiation temperature of heat generation decreased with high heating rate whereas d decomposition heat increased with particle size. Also, the explosion pressure was increased as t the ignition energy increased and average maximum explosion pressure was 13.5 kgv'cnt for 5 BJ/60 mesh and 1.5 뼈Ie미 dust concentration.

• Korean Chemical Engineering Research
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• v.48 no.1
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• pp.58-67
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• 2010

Combustion of the Korean Anthracite and wood-pellet was characterized in air atmosphere with variation of heating rate(5, 10, 20 and $30^{\circ}C/min$) in TGA. The results of TGA have shown that the combustion of the wood-pellet occurred in the temperature range of $200{\sim}620^{\circ}C$ which is much lower than that of Korean anthracite. Activation energies of the wood-pellet and Korean anthracite, determined by using Friedman method were 44.12, 21.45 kcal/mol respectively. Also, their reaction orders(n) and pre-exponential factors(A) were 5.153, 0.7453 and $4.01{\times}10^{16}$, $1.39{\times}10^6(s^{-1})$ respectively. In order to find out the combustion mechanism of the wood-pellet and Korean anthracite, twelve solidstate mechanisms defined by Coats Redfern Method were tested. The solid state combustion mechanisms of the woodpellet and Korean anthracite were found to be sigmoidal curve A3 type and a deceleration curve F1 type respectively. Also, from iso-thermal combustion($300{\sim}900^{\circ}C$) of their char, the combustion characteristics of their char was found. Activation energies of the their char were 27.5, 51.2 kcal/mol respectively. Also, pre-exponential factors(A) were $2.55{\times}10^{12}$, $1.49{\times}10^{10}(s^{-1})$ respectively. Due to the high combustion reactivity of wood-pellet compared with Korean anthracite, combustion atmosphere will be improved by co-combustion with Korean anthracite and wood-pellet.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.1059-1066
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• 2008

Characteristics of pyrolysis and liquid product distribution of ABS plastics have been studied in the thermogravimetric(TG) reactor and bomb microreactor. Pyrolysis reactions were performed at temperature $400\sim450^{\circ}C$ and yield of each pyrolytic product was obtained by the weight measurement method. The molecular weight distributions of liquid products were determined by the GC-SIMDIS method. It was observed that solid residue which could not be detected in the thermogravimetric experiments was significantly formed in the batch-type microreactor. It was found that the yield and average molecular weight of liquid products were decreased with the increase of reaction temperature and time. but the formation of styrene monomer was significantly increased. The chain-end scission rate parameters were determined to be 54.1kcal/mole far ABS by the Arrhenius plot.

• Polymer(Korea)
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• v.38 no.6
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• pp.714-719
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• 2014

Bio-based nylon 6-morpholinone random copolymers were prepared by the anionic ring opening polymerization of ${\varepsilon}$-caprolactam and morpholinone, both of which were prepared from lysine and glucose, respectively. From this work, a new biomass based nylon 6 with improved hydrophilicity was prepared. Optimizing the polymerization condition, copolymer with a viscosity-average molecular weight of 30000 g/mol was prepared, with a yield of 80%. It was possible to improve the hydrophilicity of nylon 6 by its copolymerization with morpholinone. The prepared nylon 6-morpholinone random copolymers were then characterized using several analytical methods such as DSC, TGA, XRD, viscosity measurement with U-shaped glass capillary viscometer and contact angle measurement.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.91-94
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• 2009

쌀겨회재에서 추출한 실리카원을 이용하여 메조포러스실리카 SBA-15를 합성하였으며, 이산화탄소에 대한 높은 선택성을 나타내는 아민기를 우수한 구조성을 지닌 메조포러스실리카에 그라프팅하였다. 아민기가 그라프팅된 메조포러스실리카에 높은 흡착능을 도출하기 위해서 dendrimer/SBA-15를 반응조건에 따라 합성하였다. 이와 같이 합성된 고체흡수제는 X-선 회절분석, 질소 흡,탈착 곡선, 분광분석 (FT-IR)등의 특성 분석을 수행하였고, 열중량반응기 및 충전층 반응기에서 이산화탄소 흡수실험을 수행하였다.

• Clean Technology
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• v.24 no.4
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• pp.287-292
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• 2018

Effect of physical property of activated carbon on its carbon dioxide adsorption was investigated for the effective control of carbon dioxide. Pinewood sawdust and coal were used as raw materials of activated carbon. Specific surface area, micropore volume and mesopore volume of the prepared activated carbons were determined, respectively. The prepared activated carbons were analyzed for their adsorption capacity of carbon dioxide. The adsorption capacity was then presented with respect to the surface area, micropore volume and mesopore volume, respectively. As a result, the specific surface area and micropore volume of both pinewood and coal activated carbon were highly related to its carbon dioxide capacity. Its mesopore volume hardly affected its carbon dioxide capacity. Preparation of activated carbon with high specific surface area and micropore volume was found to be critical to the effective control of carbon dioxide.