WPC was produced from corona-pretreated wood and methyl methacrylate (MMA). To remove MMA homopolymer, WPC specimens were extracted with acetone. Dimensional stability of these WPC specimens was compared with that of WPC produced by an ordinary heat catalyzed method.
The degree of apparent grafting of MMA to wood (wall polymer content) increased with an increase in corona discharging time (0-120 minutes, 15kV). The wall polymer content of the WPC exceeded that of an ordinary WPC, and it reached the maximum of 80%.
Anti-swelling efficiency (ASE) and moisture excluding efficiency (MEE) of the WPC exceeded that of the ordinary WPC, and they reached the maximum of 50 and 55%, respectively. Relationship between ASE and wall polymer content was linear in both tests of moisture and water absorption. Furthermore, relationship between MEE and wall polymer content was linear. These relationships of ASE and MEE against wall polymer content were the same as those of the ordinary WPC.
From the results of wall polymer content and dimensional stability, the most suitable concentration of MMA-methanol solution for the impregnation into wood was found to be 80%.