Research on surface modification of polymer materials with different adhesive bonding strength by cold plasma:
The wood-based panel industry is a process that divides first and then combines. The processing process depends on wood adhesives. The gluing process usually determines product quality and production line efficiency. Therefore, wood adhesives have always been one of the signs of technological progress in the wood-based panel industry.

Wood as a polymer material, plasma treatment can effectively activate its surface, significantly improve the wettability, and introduce functional groups that are conducive to improving the bonding performance.
Phenolic resin (PF) and urea-formaldehyde resin (UP) are the two main adhesives in the wood industry. The bonding performance is closely related to the surface condition of the material, and the research on improving its bonding performance through surface treatment has never stopped. In recent years, plasma The research on surface modification of polymer materials has made great progress.
As a kind of low-temperature plasma, cold plasma contains a large number of active particles such as electrons, ions, excited atoms, molecules, etc. These active particles act on the surface of polymer materials, causing very complex physical and chemical changes on the surface of the material. , Can cause etching, cracking, polymerization and other reactions, and can generate a large number of free radicals on the surface or introduce many polar groups, so that the hydrophilicity, adhesion, biocompatibility, etc. of the material are respectively improved.
The cold plasma treatment only reacts to a thickness of several tens of angstroms on the surface of the polymer material, and will not cause damage to the material itself, and can preserve the various characteristics of the original polymer material to the greatest extent.
After the veneer is treated with cold plasma, the bonding strength of the plywood has been significantly improved. Whether it is O2 plasma or Ar, NH3, N2 plasma, the bonding strength is greater than that of the blank board, and the degree of improvement is different for different adhesives. In addition, the degree of improvement is also related to the working gas of the plasma.
Regarding these three adhesives, whether it is UF, PF or PUF, the improvement range of N2 plasma is high, and the improvement effect of these four gases is N2>NH3> Ar>O2.
The veneer plywood after N2 plasma treatment can achieve the effect of phenolic glue in the bonding strength, which means that under certain circumstances, the low-cost urea-formaldehyde glue can replace the phenolic glue, which reduces the economy. Cost.
(1) Compared with blank boards, the bonding strength of veneer plywood made by plasma treatment is improved. For the three adhesives, the increase range of the same working gas is UF>PUF>PF. For the same adhesive, the effect of N2, O2, Ar, NH3 is N2> NH> Ar>O. N2 has a large improvement effect on urea-formaldehyde adhesive, reaching 88.42%, and the improved adhesive and strength almost reach phenolic formaldehyde. The strength of the glue.
(2) After the cold plasma treatment, the chemical composition and content of the wood surface have changed, and the atomic concentration ratio of surface oxygen to carbon has increased, resulting in a large amount of oxygen-containing functional groups or peroxides.
The cold plasma treatment of wood with helium, nitrogen, argon, etc. can make the surface of the wood very hydrophilic, thereby helping to improve the bonding strength of the wood.