Chemical improvement of surfaces. Part 5: surfactants as structural lead for wood hydrophobization – covalent modification with p-alkylated benzoates

Abstract

For a durable improvement of the hydrophobization properties of wood Scots pine (Pinus sylvestris L.) sapwood veneer chips were covalently modified with surfactant-like p-alkylated benzoates and a corresponding 4-cyanophenyl derivative. These esterification reactions of wood hydroxyl groups at varied temperatures and different reaction times afforded weight percent gains (WPG) ranging from 8 to 44% and quantities of covalently bonded organomaterials (QCO) of 0.3–2.6 mmol per gram, respectively. The successful covalent attachment of the functional precursors was proven by attenuated total reflection-infrared spectroscopy (ATR-IR), while the improvement of hydrophobicity was demonstrated by resulting contact angles (CAs) in a range from 113 to 150°.

Novel nicotinoid structures for covalent modification of wood: an environmentally friendly way for its protection against insects

“…The activated neonicotinoids 7c-12c were then applied in the wood modication process, developed previously in our group in order to improve the biological resistance against insects. [14][15][16][17][18] At rst, veneer chips of Scots pine sapwood were used for the modication process. To ensure a high sample throughput, the modications were performed in the "Synthesis 1" liquid system parallel synthesizer.…”

“…39,41 Furthermore, ATR-IR spectroscopy has proven as a very reliable and meaningful method in order to characterize modied wood, which is the reason why this non-destructive method has been chosen to examine all treated samples. 7,[14][15][16][17][18]39,41 Fig . 1 displays the ATR-IR spectra of untreated Scots pine sapwood in comparison to the chemically modied samples 7d-12d.…”

“…General procedure for chemical modication of wood chips following Kaldun et al 17,18 In general, the common amount of 7 mmol of the appropriate wood modifying reagent was applied per 1.00 g of veneer chips of Scots pine sapwood (approx. 10 Â 10 Â 0.7 mm 3 , approx.…”

“…Our group has developed a new and, in contrast to conventional impregnation, more environmentally friendly method for a covalent modication of wood through applying activated benzoic acids. [14][15][16][17][18] By esterication of wood with benzotriazolylactivated carboxylic acids, the material properties can be specically inuenced, while simultaneously retaining its outer appearance. The modication of wood pursues the goal to increase the lifetime of the natural material in order to improve the attractiveness and usability of the material.…”

Durable Modification of Wood by Benzoylation—Proof of Covalent Bonding by Solution State NMR and DOSY NMR Quick-Test

“…Additional improvements such as flame retardancy are in demand and have been put into practice by this concept of covalent attachment of functional organic precursors. Thus far, after initial chemical and analytical investigations in the field of common wood acetylation, we have focused on multipurpose benzoylations applying boron-, carbon-, silicon-, nitrogen-, phosphorus-, and halogen-functionalized activated benzamides as starting materials for the modification (de facto esterification) of wood hydroxyl groups [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ].…”