Effect of Kaolin Ratio on the Durability of Phenol-Formaldehyde Adhesive Poplar Plywood

2011 ◽  
Vol 183-185 ◽  
pp. 1822-1826 ◽  
Author(s):  
Ying Jie Guo ◽  
Hai Qing Ren

In order to search whether or not the kaolin ratio was one of the crucial reasons influenced on the durability of Poplar Plywood utilizing outdoor which was adhesive by phenol-formaldehyde resin. Xenon Lamp Climate Chamber process and ASTMD1037 Six-cycle method were evolved in this study to measure the durability of the plywood. There was no relativity between the kaolin ratio and the durability of the Poplar Plywood. The main factor impacting the endurance property of the Plywood was the degradations of veneer and Phenol-Formaldehyde resin caused by environmental change. The kaolin filling ratio of Phenol-Formaldehyde adhesive is not able to reduce the durability of the Poplar Plywood. Under the two method treatments, the bonding strength of the laminate wood still fulfills the Plywood GB/T17657-1999 National Stander even the ratio of kaolin is in high-level. Therefore, it is a preferable choice to adopt kaolin as filling in phenol-formaldehyde.

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1183 ◽  
Author(s):  
Yuxiang Yu ◽  
Pingping Xu ◽  
Miaomiao Chang ◽  
Jianmin Chang

The aging properties of phenol-formaldehyde resin modified by bio-oil (BPF) were analyzed using ultraviolet (UV) weathering. The variations on bonding strength of BPF were measured, and the changes on microstructure, atomic composition and chemical structure of BPF were characterized by using a scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance (NMR), respectively. With the increase of aging time, the bonding strength decreased gradually, the resin surface became rougher and the O/C radio of resin surface increased. However, the loss rate of bonding strength of BPFs was 9.6–23.0% lower than that of phenol-formaldehyde resin (PF) after aging 960 h. The aging degree of BPF surfaces was smaller in comparison to PF at the same aging time. These results showed that the bio-oil had a positive effect on the anti-aging property. Analytical results revealed that with increasing the aging time, the XPS peak area of C–C/C–H decreased, while that of C=O and O–C=O increased. The intensity of methylene and ether bridges in NMR analysis decreased along with increasing the intensity of aldehydes, ketones, acids and esters. These results indicated that the aging mechanism of BPF was a process of the breakage of molecular chains and formation of oxygen-containing compounds.


2020 ◽  
pp. 34-43
Author(s):  
N. R. Memetov ◽  
◽  
A. V. Gerasimova ◽  
A. E. Kucherova ◽  
◽  
...  

The paper evaluates the effectiveness of the use of graphene nanostructures in the purification of lead (II) ions to improve the ecological situation of water bodies. The mechanisms and characteristic parameters of the adsorption process were analyzed using empirical models of isotherms at temperatures of 298, 303, 313 and 323 K, which correspond to the following order (based on the correlation coefficient): Langmuir (0.99) > Temkin (0.97) > Dubinin – Radushkevich (0.90). The maximum adsorption capacity of the material corresponds to the range from 230 to 260 mg/g. We research the equilibrium at the level of thermodynamic parameter estimates, which indicates the spontaneity of the process, the endothermic nature and structure change of graphene modified with phenol-formaldehyde resin during the adsorption of lead (II) ions, leading to an increase in the disorder of the system.


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