Wood-polymer materials impregnation

Just as wood may be impregnated with additives to improve physical properties, a variety of porous polymers also benefit from polymer impregnation. As more and more specialized applications arise, it is necessary to produce polymeric materials with very specific surface and bulk properties. The correct combination of properties may not be obtainable using a single polymer or copolymer. However, polymeric materials may be impregnated with an additive in order to modify the surface energy, bondability, hydro-philicity, and other important properties. 

Figure 2 Creep-recovery tests of chemically treated woods. U, untreated wood Fs, vapor phase formalization F, liquid phase formalization A, acetylation PO, etherification with propylene oxide MG, treatment with maleic acid and glycerol PFl, impregnation with low molecular weight phenol-formaldehyde resin PEG-ICP, impregnation with polyethylene glycol (PEG-IOOO) WPC, formation of a wood- polymer composite (PMMA) WIC, formation of a wood-inorganic material composite.

Applications of supercritical fluids for coatings and impregnation of porous and fibrous substrates (e.g., polymer fibers, wood, composite materials) with various chemicals are discussed in a number of articles (50-52). Mandel and Wang (53) reported the use of a solution of polymers diluted with SCCO2 for powder-coating applications. They reported that Ferro Corporation has developed the so-called VAMP process used in the production of powder coatings, new polymers and polymer additives, and various biomaterials, with good potential for productions of pharmaceuticals. 

A fire retardant polymer that is easily impregnated into wood to petrify the material, making it stronger and nonflammable. 

The length of the polymer chain of these two organometallic polymers makes them rather viscous for use as wood impregnants, so it was decided to try impregnating with monomeric materials and polymerizing "in situ". Methyl methacrylate, trlbutyltin... 

Wood was soaked or impregnated with chemicals. After that they were set in a hot press and pressed at 160 iC/0.5-2MPa for 5-30min. [Heat-Pressed Treatment]. Comparison specimens were set in a hot oven and dried at 160 °C for 2-6hrs. [Heat-Dried Treatment]. Heat pressed material was put on top of each other or untreated material with emulsion polymer-isocyanate adhesives to make a laminated board. 

OTHER COMMENTS used during the manufacture of electric equipment as an insulating material used as an inert compound of resins or polymers for coating or impregnating textiles, wood and paper to impart flame resistance and water proofhess useful as an additive to special lubricants in crankcase oil, lubricants for farm machinery, and extreme-pressure lubricants an additive for cutting oil in various operations performed on metals. 

IMPREGNATION OF SOFT SOUND WOOD WITH MONOMERS, which are then polymerized in situ by 7 radiation, was a method used in many laboratories during the 1960s in an effort to obtain wood-plastic composites. The process was attractive in two respects there was a large choice of consolidants, and radiation-induced polymerization had many advantages. Various vinyl monomers are cured by 7 rays. By proper selection of the polymer or copolymer, materials can be tailor made for specific applications. The radiation process presents several advantages over the chemically catalyzed polymerization of monomers in wood. 

The third part, Chapters 10-12, examines the properties of composites, where one component is usually nonpoly meric. Two broad classes of composites are treated polymer-impregnated materials, such as wood or concrete, and fiber- and particle-reinforced plastics and elastomers. The approach throughout draws upon basic chemistry, materials science, and engineering. The phases discussed here tend to be large and well-defined, but the interactions at the phase interfaces remain crucial in determining properties. 

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