Selected Properties of Compregnated Wood Using Low Molecular Weight Phenol Formaldehyde and Succinic Anhydride

Abstract

The aim of this study was to investigate the effect of impregnating materials (low molecular weight phenol formaldehyde or LmwPF and succinic anhydride or SA), their concentrations (5and 10%), and compression ratios (20 and 40% from initial thickness)on improvement of specific gravity (SG) and dimensional stability on nyatoh, sepetir, and pisang putih wood; and then compared them to control and densified wood. The results showed that SG and dimensional stability of compregnated wood were affected by all parameters studied. Higher compression ratio and concentration will result in a greater improvement.In general, SG and dimensional stability of compregnated wood were better than the control.SG of LmwPF-and SA-compregnated wood increased by 10.69‒22.31% and 6.96‒23.09%, respectively. Utilization of LmwPF and SA has significantly reduced the spring-back, butthe latter is better. Thecompression-set recovery after compregnation was 18.34‒33.99%, while after densification was 47.86‒71.49%.

Effect of Sodium Hydroxide, Succinic Acid and Their Combination on Densified Wood Properties

“…This phenomenon occurred due to higher WPG values in sepetir wood (Figure 4), which could prevent the deformation of cells during compression. This finding coincided with the results of Augustina et al [31]. They stated that the presence of impregnating substances can prevent wood deformation during compression, resulting in lower C-set values in compregnated wood compared to densified wood.…”

“…Sepetir wood showed the highest improvemen for all treatment categories and the value was significantly different species. This phenomenon was related to its initial specific gravity (th its anatomical features, i.e., greater void volume due to a greater vessel ber of vessels [12,[29][30][31]. A higher void volume resulted in a higher le in the cell lumens during compression and, as a result, the wood wa This finding coincided with Darwis et al [32], who stated that the gravity after densification is mainly influenced by the porosity or pro ties.…”

“…Sepetir wood showed the highest improvement in specific gravity for all treatment categories and the value was significantly different from the two other species. This phenomenon was related to its initial specific gravity (the lowest) as well as its anatomical features, i.e., greater void volume due to a greater vessel diameter and number of vessels [12,[29][30][31]. A higher void volume resulted in a higher level of deformation in the cell lumens during compression and, as a result, the wood was more compacted.…”

“…On the other hand, a higher WPG could also increase oven-dried weight, thus influencing specific gravity values. According Augustina et al [31], impregnating agents would be deposited and solidified in the cell cavity and thus could increase both WPG and specific gravity. This was also agreed with by Nur et al [35], who stated that there is a positive correlation between WPG and SG.…”

Wood impregnation in relation to its mechanisms and properties enhancement

“…Hardwood and softwood have been impregnated with a variety of impregnating agents such as waxes and oils (Lesar and Humar 2011;Esteves et al 2014;Ahmed et al 2017;Belchinskaya et al 2021), thermosetting resins, including epoxy, phenol formaldehyde, urea formaldehyde, etc. (Furuno et al 2004;Gabrielli et al 2010;Zhao et al 2016;Biziks et al 2018;Schwarzkopf et al 2020;Wang and Zhao 2022), monomer/polymer, including methacrylate, acrylate, styrene, unsaturated polyester, followed by radiation or catalyst-thermal treatment (Chao et al 2003;Hadi et al 2013), noncyclic and cyclic anhydride (Li et al 2001;He et al 2020;Augustina et al 2021), as well as organic acid (Fang et al 2000;L'Hostis et al 2017;Grosse et al 2019;Lee et al 2020;Augustina et al 2022). These types of impregnating agents have been classified as either nonbonded-leachable (NBL), nonbonded-nonleachable (NBNL), or bondednonleachable (BNL), depending on the bonding efficiency of the impregnating agent to and from the wood cells (Rowell and Young 1981).…”