Papers by Keyword: Phenolic Resin

Abstract: The necessary thermal insulation for buildings was provided for years optimally by polymer foams. Generally the foam is based on petrochemical resources. It is used for external wall insulation and not employed for additional functions. A Sandwich build of rigid laminates and a quite shear resistant polymer foam core results in an extraordinary stiff element. This provides thermal insulation and forms an independent load carrying structure. The sustainability of the sandwich structure can be raised by combining materials from renewable resources. The sandwich system currently developed, in cooperation with our partner from industries C3 Technologies, consists of lignin based foams of varying density and natural fibre reinforced laminates. The lignin is produced from beech-wood via the organosolv-process. Afterwards it is chemically integrated into the phenolic resin. The proportion of lignin in the resin can be varied from 10% up to 40%. This poses a quite prospective idea since using lignin means using nature’s own synthesis instead of artificial petrochemical processes for resin production and thus reducing the energy needed for resin production

Abstract: By blending the different ratio of the low viscosity of bisphenol A type epoxy resin with low viscosity ammonia catalytic phenolic resin, the performance of the resin systems were investigated by the gel time, viscosity, mechanical properties, heat resistance, flame retardance. In addition, DSC was used to detect the thermal property, and FT-IR monitored the reactive process of phenolic-epoxy resin. When the phenolic resin was mixed with 5% epoxy resin, the results were as follow: the gel time of 121 s at 150°C, viscosity of 7760 mPa·s at 30°C, flexural strength of 83.3 MPa, impact strength of 6.9 kJ/m², tensile strength of 20 MPa, heat deflection temperature of 148.5°C, oxygen index of 34.5% and the apparent cure activation energy of 94.2kJ/mol. The resin systems had higher service temperature, low viscosity, excellent mechanical properties and service characteristics, and it could meet the requirements of fast pultrusion process.

Abstract: Silicone-modified phenolic resin was prepared by synthesizing phenol, formaldehyde and phenyltrimethoxysilane, which were supported by Fourier Transform Infrared Spectoscopy (FT-IR). The carbon residual rate of Silicone-modified phenolic resin increased steeply when the silicone modifier was added increasing from 5% to 15%(on resin base) which was tested in an air atmosphere,from room temperature to 800 °C by Thermogravimetric Analysis (TG) ,modified resin of 15% silicone modifier had the highest carbon residue rate. Curing process of silicone-modified phenolic resin determined by Differential Scanning Calorimetry (DSC) was: 80°C/4h+100°C/2h+120°C/2h+160°C/3h+180°C/2h. Curing Kinetic Study on silicone-modified phenolic resin was made to understand the curing process better.

Abstract: In this study, the tensile strength of phenolic resin adhesive was reinforced by the use of surface-modified nanocrystalline cellulose (NCC). The original NCC was modified by 3-methacryloxy-propyltrimethoxysilane (MPS) to improve the wetting property with the phenolic resin adhesive. The phenolic resin adhesive with surface-modified NCC was analyzed by Fourier transform infrared (FT-IR). Tensile strength of the modified phenolic resin adhesive was tested according to Chinese National Standard GB/T 2567-2008. The results showed that the wetting property between NCC modified by MPS and phenolic resin adhesive was increased by 21.7% and the tensile strength of phenolic resin adhesive with modified NCC was enhanced from 6.25 MPa to 15.97 MPa.

Abstract: Porous carbon monoliths are prepared by carbonization of a simple polymer blend, in which phenolic resin (PF) as carbon precursor, polyvinyl butyral as pore former and activated carbon as conducting additive and contraction inhibitor are used to make polymer blend. The results show that the carbon monoliths, with a narrow pore size distribution with mean controlled diameters in the sub-micron/micron range, can be easily produced by controlling the stabilization temperature of the PF, the carbonization temperature, and particle diameters of the precursor powders. The pore size decrease as the stabilization temperature of the PF increases or the particle diameters of the precursor powders decreases. The electrical resistance of the carbon monoliths decreases as the carbonization temperature increases, but the average pore diameter and volume of the carbon monoliths are almost constant as the carbonization temperature increases.

Abstract: Si₃N₄-SiC-C refractory composites were prepared under the condition of 1100 °C × 1 h with Si₃N₄ and SiC as the raw material and the sucrose and phenolic resin as the binder. The effects of the amount of the sucrose in the binder on the properties of Si₃N₄-SiC-C refractory composites were studied. The results indicated that increasing the ratio of sucrose in the binder can improve the properties of the materials.

Abstract: Previously bamboo fiber reinforced PP composites was manufactures using Polyvinyl Alcohol (PVA) and Phenolic resin for Resin impregnated bamboo fiber with polypropylene (PP). Using 40% weight fraction of bamboo fiber in PP matrix, PVA impregnated composites with mean flexural and tensile strength 10% higher than untreated were produced. The PVA treatment improved the tensile and flexural strength of bamboo/PP composites and increased water absorption ratio. Next, matrix modified with Maleic Anhydride grafted Polypropylene (MAPP). For matrix PP mixed with 10% of MAPP. In this study, resin impregnation method dose not make different for mechanical properties of composites. Untreated and PVA, Phnolic resin impregnated mechanical properties was almost same. However; it can decreased water absorption PVA resin absorption bamboo fiber composites.

Abstract: In order to improve the coke residue of phenolic resins (PF), different solvents were used in the present work. The research indicates that in comparison with other solvents, such as ethylene glycol (EG) and ethyl silicate (ES), furfural (FF) can enhance crosslinking density and increase residual coke yield of phenolic resins (PF). The results demonstrate that the residual coke yield of PF with furfural is 68 % higher than that with other solvents. In addition, pyrolysis peak temperature of PF with furfural is relatively high and pyrolysis process is more smoothly. FTIR results show that new bonds formed in PF when take furfural as solvent, and furfural changed the structure of phenolic resins. Raman spectra analysis results show that the order degree of the carbonized products (treated at 800 °C) is higher than that in other solvents, and stability of the carbonized products is improved. The research concludes that the type of solvent has great influence on the structure and coke residue.

Abstract: ZnO-based ceramic was densified at low temperature by using PSP as binder. The results showed that phenolic resin filled in the ZnO grain boundary layer. The sample has a well hardness of 0.8 GPa and bending strength of 78 MPa. The effect of temperature on the microstructure and mechanical properties was also investigated. It was found that the samples sintered at 300 °C showed higher density and better mechanical properties.

Abstract: Resin-derived carbon foams with closed hollow spherical structure were prepared from mixtures of hollow phenolic microspheres and phenolic resin, followed by curing and carbonization. The resultant carbon foam had a bulk density of 0.45 g·cm^-3. Effects of hollow microsphere on the on the compressive property and thermal conductivity of carbon foams were investigated. The results revealed that the hollow microspheres played an important role in improving compressive fracture toughness and lowering the thermal conductivity of carbon foams. The compressive fracture characteristics of carbon foam exhibited gradient brittle fracture, and the compressive strength was 10.93 MPa. The thermal conductivity of the carbon foam was 0.907 W·m^-1·K^-1 at room temperature, which was lowered by 49.67 % in comparison with phenolic-based vitreous carbon.