• Journal of the Korean Institute of Gas
• /
• v.17 no.1
• /
• pp.35-41
• /
• 2013

In this study, flame retardancy of polyurethane foam and phenolic foam were investigated by addition of phosphorous flame retardants. The thermal degradation behavior of polyurethane foam and phenolic foam in the presence of flame retardants has been studied by thermogravimetric analysis(TGA). Heat release rate(HRR), mean HRR, mass loss rate(MLR), total smoke released(TSR) and limited oxygen index(LOI) were tested by cone calorimeter. From the test results, Phenolic foam showed low HRR, MLR and TSR than polyurethane foam.

• Macromolecular Research
• /
• v.17 no.2
• /
• pp.121-127
• /
• 2009

The cure kinetics of the epoxy-layered, silicate nanocomposites were studied by differential scanning calorimetry under isothermal and dynamic conditions. The materials used in this study were o-cresol novolac epoxy resin and phenol novolac hardener, with organically modified layered silicates. Various kinetic parameters, including the reaction order, activation energy, and kinetic rate constants, were investigated, and the storage stability of the epoxy-layered silicate nanocomposites was measured. To synthesize the epoxy-layered silicate nanocomposites, the phenolic hardener underwent pre-intercalation by layered silicate. From the cure kinetics analyses, the organically modified layered silicate decreased the activation energy during cure reaction in the epoxy/phenolic hardener system. In addition, the storage stability of the nanocomposite with the pre-intercalated phenolic hardener was significantly increased compared to that of the nanocomposite with direct mixing of epoxy, phenolic hardener, and layered silicate. This was due to the protective effect of the reaction between onium ions and epoxide groups.

• Advances in materials Research
• /
• v.3 no.3
• /
• pp.175-183
• /
• 2014

Natural rubber bound phenolic antioxidant, 2,6-di-tert-butyl-4-vinylphenol (2,6-DBVP), was prepared from natural rubber and 2,6-DBVP in both solution and melt state. The 2,6-DBVP had been synthesized from 3,5-di-tert-butyl-4-hydroxybenzaldehyde and methyltriphenylphosphonium iodide ($MePPh_3I$) by Wittig reaction ($0^{\circ}C$ for 2 hrs, $N_2$ atmosphere). The conditions for preparation of natural rubber bound 2,6-DBVP (NR-DBVP) were optimized for both solution state (1 phr BPO and 8 phr 2,6-DBVP at $70^{\circ}C$ for 2 hrs) and for melt state (1 phr BPO and 8 phr 2,6-DBVP at $70^{\circ}C$ for 10 mins, with rotor speed of 60 rpm). A thermoplastic vulcanizate was obtained using a compatibilizer, polypropylene modified with phenolic resin (PhHRJ-PP), in a closed mixer ($180^{\circ}C$ for 3 mins, rotor speed 60 rpm). The antioxidant properties of vulcanized NR-DBVP, using phenolic as the vulcanization system, were similar to NR with the conventional antioxidant BHT. In addition, the antioxidant, water leaching property of the thermoplastic vulcanizate of NR-DBVP/PP were good in comparison to a NR blend with BHT; the morphologies of these thermoplastic vulcanizates were similar.

• Journal of Microbiology and Biotechnology
• /
• v.6 no.2
• /
• pp.116-119
• /
• 1996

The biological treatment by a mixed culture GE2 immobilized on activated carbon was investigated with a phenolic resin industrial wastewater containing 41,000 mg/l of phenol and 2,800 mg/l of formaldehyde. At a dilution of 20 times with aerated tap water, influent and effluent $COD_{Mn}$ were 4,587 mg/l and 46 mg/l, that is, $COD_{Mn}$ removal efficiency was 99.0%. At this time, phenol and formaldehyde con-centration of the effluent were 1.24 and 6.80 mg/l, indicating removal efficiencies of 99.9 and 94.1%, respectively.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2001.10a
• /
• pp.133-136
• /
• 2001

The effect of pre-carbonization condition on the mechanical properties of nonwoven needle-punched carbon/phenolic composite was studied. The nonwoven Oxi-PAN felt was pre-carbonized at different temperature. The pre-carbonized Oxi-PAN felt was needle-punched and then carbonized. Needle-punched nonwoven carbon preforms were formed into composites with phenol resin. The tensile and flexural strengths showed maximum value with pre-carbonization temperature of $500^{\circ}C$. Compared with the non-pre-carbonized composite, the mechanical properties were slightly improved.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2004.04a
• /
• pp.63-66
• /
• 2004

In this study, a hybrid composite journal bearing composed of carbon fiber reinforced phenolic composite liner and metal backing was manufactured to solve the seizure problem of metallic journal bearing materials because the carbon fiber has self-lubricating ability and the phenolic resin has thermal resistance characteristics. To estimate the wear resistance of carbon fiber phenolic composite, wear tests were performed at several pressures and velocities. The oil absorption characteristics, coefficient of thermal expansion, strength and stiffness of the composite were also tested. Using the measured stiffness values, the thermal residual stresses in the composite were calculated to check the reliability of the composite journal bearing.

• Journal of the Korean Wood Science and Technology
• /
• v.49 no.4
• /
• pp.360-370
• /
• 2021

For the purpose of finding new uses for Miscanthus sinensis var. purpurascens, this study first constructed boards with the particles of the plant and impregnated them with phenolic resin at resin impregnation rates of 30 ± 2%, 40 ± 2%, 50 ± 2%, and 60 ± 2%. The impregnated boards were then carbonized at the carbonization temperature of 800℃, after which their density and mechanical properties were examined according to the different resin impregnation rates. The results showed that density, flexural strength performance, Brinell hardness, and compressive strength increased as the resin impregnation rate increased, thus affecting the physical and mechanical properties of the ceramics made of M. sinensis var. purpurascens particles.

• Journal of the Korean Ceramic Society
• /
• v.52 no.4
• /
• pp.284-289
• /
• 2015

This study examined carbon layer coating on silicon carbide (SiC) fibers by utilizing solid-state and wet chemistry routes to confer toughness to the fiber-reinforced ceramic matrix composites, as an alternative to the conventional pyrolytic carbon (PyC) interphase layer. Electrophoretic deposition (EPD) of carbon black nanoparticles using both AC and DC current sources, and the vacuum infiltration of phenolic resin followed by pyrolysis were tested. Because of the use of a liquid phase, the vacuum infiltration resulted in more uniform and denser carbon coating than the EPD routes with solid carbon black particles. Thereafter, vacuum infiltration with controlled variation in phenolic resin concentration, as well as the iterations of infiltration steps, was improvised to produce a homogeneous carbon coating having a thickness of several hundred nanometers on the SiC fiber. Conclusively, it was demonstrated that the carbon coating on the SiC fiber could be achieved using a simpler method than the conventional chemical vapor deposition technique.

• Analytical Science and Technology
• /
• v.12 no.6
• /
• pp.504-508
• /
• 1999

We have studied structural charecterization, electrical charge and discharge, and impedence properties for polyacene anode material derived from phenolic resin of novolak type. From the X-ray diffraction results, diffraction patterns for compounds of the three kinds of P-700, P-850, P-1000 were observed for semiirregular structural transition. A electrical charge and discharge data showed that the properties of p-850 was much better than any other samples. From the impedence properties for finding the effect of ions and electron transfer of battery, P-1000 and P-850 of high frequency of real number showed good electrical impedence properties.

• Microbiology and Biotechnology Letters
• /
• v.24 no.6
• /
• pp.743-748
• /
• 1996

For the biological treatment of phenolic resin wastewater containing phenol and formaldehyde, a phenol-degrading yeast was isolated from the papermill sludge, and then identified as Candida tropicalis PW-51 according to morphological, physiological and biochemical properties. The strain was able to degrade high phenol concentrations up to 2,000mg/l within 58 hours in batch cultures. Phenol-degrading efficiency by the strain was maximum at the culture conditions of a final concentration of 9 $\times$ 10$^{6}$ cells/ml, 30$\circ$C and pH 7.0. The mean degradation rate of phenol was highest at 45.5mg/l/h in 1,000mg/l phenol from 500mg/l to 2,000mg/l phenol. Because the enzyme activity of catechol 1,2-dioxygenase increased in the course of degradation of phenol, it seems that this strain degrades phenol via the ortho-cleavage of benzene ring. The isolate C. tropicalis PW-51 could be effectively used for the biological treatment of phenolic resin wastewater.