• The Korean Journal of Rheology
• /
• v.11 no.2
• /
• pp.135-142
• /
• 1999

The effects of 1 wt.% N-benzylpyrazinium hexafluoroantimonate (BPH) as a thermal latent initiator and blend compositions composed of 0, 5, 10, 20 and 40 wt.% of phenol-novolac resin to epoxy resin were investigated in terms of cure kinetics, thermal stabilities and rheological properties. Thermal latent properties of BPH were measured from the conversion as a function of reaction temperature on a dynamic DSC. This cationic BPH system turned out to be an effective thermal latent initiator in the epoxy-phenol curing system. And the increase of phenol-novolac resin concentration led to the decrease in the latent temperature and to the increase of cure activation energy ($E_a$) of the blend system. The thermal stability and activation energy ($E_t$) for decomposition, gel-time and activation energy ($E_c$) for cross-linking from rheometer increased within the composition range of 20~40 wt.% of phenol-novolac resin. This implies that the three-dimensional cross-linking may take place among hydroxyl group within phenol resin, epoxide ring within epoxy resin and BPH.

• Journal of the Korean Wood Science and Technology
• /
• v.26 no.2
• /
• pp.6-15
• /
• 1998

A total of forty five-ply, 30- by 30-cm lauan and larch plywood sheets were manufactured in the laboratory using commercial urea and phenol resin adhesives; half of these sheets were treated with fresh concrete. Each sheet was carbonized for 2, 4, and 6hours at $400^{\circ}C$, $600^{\circ}C$, and $750^{\circ}C$, respectively, and their physical properties were measured. The yie1d of charcoal decreased as carbonization temperature and time increased. Charcoal yield was greater in plywood than in veneer, and slightly greater in plywood treated with concrete compared to untreated plywood. Plywood manufactured with phenol resin adhesive had higher pH, higher equilibrium moisture content (EMC), and greater adsorption of methylene-blue dye compared to plywood manufactured with urea resin. For concrete-treated plywood, pH was greater than 10 even when the sheets were carbonized for 2hours at $400^{\circ}C$. Although the EMC of the phenol resin plywood was higher than that of the urea resin plywood, EMC of the phenol resin was lower than that of the urea resin. The larch phenol resin plywood that was carbonized for 6 hours at $750^{\circ}C$ adsorbed more methylene-blue than did the commercia1 wood-based activated charcoal as a result of total pore volume and surface area.

• Journal of Preventive Medicine and Public Health
• /
• v.19 no.2 s.20
• /
• pp.224-232
• /
• 1986

This study was conducted to evaluate health consequences of phenol resin workers for 6 weeks from February 21, to March 28, 1986. The subject population was 26 in a factory with phenol resin and control group was 30 non-exposed workers who were working in the other factory. The biological parameters chosen for this study were phenol concentration in working room-air, total phenol level in urine and BUN of phenol resin workers. The phenol concentration in working room-air and total phenol in urine were significantly correlated (r=0.791, p<0.01). The frequency of symptom and sign in phenol resin workers were higher than control group. The frequent symptom and sign were coughing, weight loss, poor appetite, headache, dyspnea, eye irritation and tinnitus, in order. Total phenol in urine was not reversed to normal range in spite of interruption of exposure for 4 days. The BUN value in blood and total phenol in urine were not correlated.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.36 no.5 s.108
• /
• pp.78-84
• /
• 2004

Lignin precipitated from black liquor of soda pulping of bagasse was used to prepare cation-exchange resin. The effect of sulfuric acid treatment, concentration of phenol and formaldehyde on the properties of the prepared cation-exchange resin was investigated. It was found that sulfonated resinified phenolated lignin gave a resin with an ion-exchange capacity higher than that of resin, which resulted from sulfonation of resinified lignin at zero phenol concentration. Infrared spectroscopy of the prepared ion-exchange resin shows anew bands at 1060, 1160, 1280 and $1330\;cm^{-1}$ which indicated to the presence of $SO_{3}$.

• Journal of the Korean Wood Science and Technology
• /
• v.26 no.1
• /
• pp.87-96
• /
• 1998

The bending performances were evaluated at the radiata pine plywood through veneer compositions encompassing veneer quality, ply-numbers and overlays of the high density- or medium density-phenol resin impregnated sheets (hereafter abbreviated as resin sheets) on the raw plywood. In addition, a prediction on the bending MOE of veneers and plywoods was carried out by the nondestructive testing with stresswave timer. The summarized results were as follows: I. Bending strength and bending MOE of resin sheets-overlaid plywoods in parallel surface grain direction through 5 and 7ply were increased by 13 to 45% and 17 to 34%, respectively. Resin sheets-overlay occurred an increasing effect of the strength efficiency i.e. strength perpendicular-to-grain direction versus that parallel-to-grain direction, showing the phenomenon that the plywood strength becomes greater at the perpendicular-to-grain direction of 7ply than at that of 5ply. Displacement at bending failure had a greater trend at 7ply than at 5ply, and was decreased by resin sheets-overlay. 2. After the nondestructive bending MOEs were measured for individual veneers, these veneers were rearranged in plywood-manufacture. In these plywoods, including resin sheets-overlay, the actual MOE was predictable with feasibility of $R^2$=0.53, and also the nondestructively-evaluated MOE was lower by 20% in raw plywood, and higher 20% in LVL than actual bending MOEs.

• Journal of the Korean Wood Science and Technology
• /
• v.32 no.3
• /
• pp.25-32
• /
• 2004

This research work explored physical and mechanical properties of impregnated sawdust boards from three softwood species (P, densifora, L. kaemferi, and P. koraiensis) with phenol-formaldehyde (PF) resin by various vacuum treatment methods of combining pressure, vacuum, and ultrasonic waves. Simultaneous vacuum and ultrasonic wave treatments with no pressure resulted in the greatest increase in resin content, density, dimensional changes (thickness and length), bending strength, and hardness of impregnated board. This result seemed to be attributed to the ultrasonic wave treatment.

• Applied Chemistry for Engineering
• /
• v.16 no.2
• /
• pp.288-291
• /
• 2005

Resol type phenol-formaldehyde (PF) resin was synthesized by addition reaction of formaldehyde (F) and phenol (P). And the PF resin was synthesized by condensation reaction in which water was removed. In this work, we studied the influence of experimental parameters in the addition reaction, such as F/P mole ratio, amount of catalyst, reaction temperature, reaction time, and so on. Also, we studied the influence of molecular weight and viscosity of PE resin as a function of condensation time. As a result, in addition reaction, the reaction time decreased remarkably as the catalyst concentration increased, and the time decreased with increasing reaction temperature at a constant catalyst concentration. Also, in condensation reaction, the viscosity of resol type PF resin increased from 1500 to 9000 cps as a function of condensation time; molecular weight showed from 500 to 1100 g/mol.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.9
• /
• pp.27-33
• /
• 2016

Phenolic resin has excellent heat resistance and good mechanical properties as a thermosetting resin. However, its thermosetting characteristics cause it to produce a non-recyclable waste in the form of sprue and runner which is discarded and represents up to 15~20% of the overall products. Forty thousand tons of phenolic resin sprue and runner are disposed of (annually). The (annual) cost of such domestic waste disposal is calculated to be 20 billion won. In this study, discarded phenol resin scraps were pulverized and treated by silanes to improve their interfacial adhesion with HDPE. The sizes of the pulverized pulverulent bodies and fine particles were (100um~1000um) and (1~100um), respectively. The pulverized phenol resin was treated with 3-(methacryloyloxy) propyltrimethoxysilane and vinyltrimethoxy silane and the changes in its characteristics were evaluated. The thermal properties were evaluated by DSC and HDT. The mechanical properties were assessed by a notched Izod impact strength tester. When the silane treated phenol resin was added, the heat distortion temperature of HDPE increased from $77^{\circ}C$ to $96^{\circ}C$ and its crystallinity and crystallization temperature also increased. Finally, its impact strength and tensile strength increased by 20% and 50%, respectively, in comparison with the non-treated phenol resin.

• Journal of the Korean Electrochemical Society
• /
• v.3 no.2
• /
• pp.85-89
• /
• 2000

For replacing Li metal at Lithium ion Battery(LIB) system, we used carbon powder material which prepared by Pyrolysis of Phenol resin as starting material. It became amorphous carbon by Pyrolysis through it's self condensation by thermal treatment. Amorphous carbon can be doped with Li intercalation and deintercalation because it has wide interlayer. However, it has a problem with structural destroy due to weak carbon-carbon bond. So, we used $ZnCl_2$ as the pore-forming agent. This inorganic salt was used together with the resin serves not only as the pore-forming agent to form open pores, which grow into a three-dimensional network structure in the cured material, but also as the microstructure-controlling agent to form a loose structure doped with bulky dopants. We used SEM in order to find to difference of structure, and can calculate the distance of interlayer by XRD analysis. CV test showed oxidation and reduction.

• Korean Chemical Engineering Research
• /
• v.58 no.4
• /
• pp.618-623
• /
• 2020

Spherical phenolic resin beads were synthesized by suspension polymerization at 98 ℃ from phenol, ortho-cresol, formaldehyde, with triethylamine as a basic catalyst, and spherical phenol-cresol copolymer resin beads with relatively low crosslinking density as well. Phenol reacts with formaldehyde at two ortho- and one para- positions to form a crosslinked structure, but ortho-cresol instead of phenol reduces the crosslinking density during copolymerization due to the methyl group at a ortho- position. As a result, spherical phenol-cresol copolymer beads showed more shrinkage with decreasing apparent density compared to the spherical phenol beads when carbonized at 700 ℃ under nitrogen. As the molecular weight of the cresol oligomer increases, the pore radius of the carbonized copolymer beads decreases, which is consistent with the density and shrinkage results. It was confirmed that the characteristics such as density decrease, shrinkage, yield and so on during carbonization can be controlled by controlling the degree of crosslinking of the spherical phenolic resin particles with cresol.