Papers by Keyword: Phenol Formaldehyde

Abstract: High demand for wooden materials and rises in agricultural areas and forest fires increased the importance of composite particleboard instead of using solid woods. Particleboards are among the most popular materials used in interior and exterior applications. The objective of this study was to examine the physical and mechanical properties of phenol formaldehyde particleboard made from oil palm trunk (OPT) with 11% resin content. Two different board thicknesses were use; 12mm and 16mm. The particle size use in this study was 2mm and 1mm. Phenol formaldehyde (PF) was used as the binder. The result showed that modulus of rupture and modulus of elasticity were perform better at 16mm board thickness with 1.0mm particle size and meet the standard. The internal bonding strength was parallel with bending strength.

Abstract: Brake pads are composite materials which have been constantly improved by new materials that increase the quality and reduce the non-renewable raw materials. The goal of this work is to study the behavior of brake pads produced with replacement of phenol-formaldehyde resin by lignin up to 40% weight ratio. The Krauss method of characterization and SEM analysis were employed. The results showed an average friction coefficient approximately to μ_m=0.4 and a heterogeneous surface morphology. The satisfactory results are compatible with the current friction materials.

Abstract: The flexural properties of SLG filled phenolic composites have been determined in previous study. It is time consuming to prepare the samples for the tests. In addition, it is even more time consuming to carry out the tests and analyze the results. It is therefore necessary to develop a mathematical model that will predict the flexural properties of particulate filled phenolic composites. Mathematical models for tensile strength, Young’s modulus are available but not for impact strength, flexural strength and fracture toughness. There is no sign that it can be built up from simple mathematical model; polynomial interpolation using Lagrange’s method was therefore employed to generate the flexural properties model using the data obtained from experiments. From experiments, it was found that the trend of the flexural properties of the samples post-cured conventionally was similar to that post-cured in microwaves; it is therefore possible to predict the flexural properties of the samples post-cured in microwaves from the mathematical model generated for flexural properties of samples post-cured in a conventional oven. The workload is therefore halved as the process of generating the mathematical was much faster and simpler.

Abstract: Short carbon fiber is used to reinforce phenol formaldehyde (PF) resin/graphite composite. With carbon fiber by thick nitric acid liquid-phase oxidative surface treatment (TNALPOST) and its content 3.wt%~ 4.wt%, the composite flexural strength is increased highly and electrical conductivity is also increased on some degree. To PF resin/graphite matrix material without carbon fiber added, if PF resin content is 15.wt%, its flexural strength is 49.0MPa and electrical conductivity is 111S/cm. But with adding carbon fiber by TNALPOST and the same PF resin content , the composite flexural strength and electrical conductivity approach 68MPa、122S/cm respectively, both mechanical property and electrical property satisfy the requirement of USA Department of Energy on carbon filler/polymer composite bipolar plate. The PF resin/graphite composite without carbon fiber added presents brittle fracture mode, but with carbon fiber added, it presents ductile fracture mode. According to the fracture morphology by scanning electron microscopy, carbon fiber and matrix is on relatively weak boundary bonding state accompanied by fiber de-bounding、sliding、pulling-out and bridge-making to crack, they are main factors contributed to improving composite toughness.

Abstract: A commercial phenol formaldehyde based resole thermosetting resin supplied by Borden Chemical Australia Pty. was filled with ceramic-based fillers (Envirospheres or SLG) to increase its flexural strength. By performing flexural tests at a range of filler addition levels, the optimal addition level of SLG was able to be determined in terms of workability, cost and performance. The composites obtained were post-cured in conventional oven and in microwaves respectively. It was found that the maximum flexural strength of the microwave cured composites were only 5% lower than those cured in conventional oven when the percentage by weight of SLG was 24%. However, the time required for post-curing was also reduced from 10 hours (in conventional oven) to 40 minutes (in microwaves).

Abstract: The fracture toughness of SLG filled phenolic composites have been determined by short bar tests. It is expensive to prepare the samples for the tests. Therefore, it is necessary to develop a mathematical model that will predict the fracture toughness of particulate filled phenolic composites. Mathematical models for tensile strength, Young’s modulus are available but not for impact strength and fracture toughness. There is no sign that it can be built up from simple mathematical model; polynomial interpolation using Lagrange’s method was therefore employed to generate the fracture toughness model using the data obtained from experiments. From experiments, it was found that the trend of the fracture toughness of the samples cured conventionally was similar to that cured in microwaves; it is therefore possible to predict the fracture toughness of the samples cured in microwaves from shifting the mathematical model generated for fracture toughness of samples post-cured in conventional oven. The shifted model represented the fracture toughness of the samples cured in microwaves vey well.