Penetration depth of phenol-formaldehyde (PF) resin into beech wood studied by light microscopy

Biziks, Vladimirs; Bicke, Sascha; Militz, Holger

doi:10.1007/s00226-018-1058-2

Cited by 42 publications

(30 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the previous work, both the chemical and mechanical properties of wood cell walls penetrated by PF resin during the wood gluing were characterized by AFM-based infrared spectroscopy (AFM-IR), which further confirmed that the physical filling and the possible chemical reactions are increasingly considered as the major contributions to the improved wood properties such as bending strength and hardness [15,16]. It is well-known that the depth and capacity of penetration was prone to be influenced by the compatibility between the chemical and physical characteristics of the wood and resin and by the process used [12]. However, only limited attempts have been made to analyze the chemical, physical, and mechanical properties of the wood cell wall after PF resin modification by vacuum-pressure impregnation.…”

Section: Introductionmentioning

confidence: 83%

“…Thus, more researchers have focused on investigating the penetration phenomena of PF resin into wood for clarifying the modification mechanisms. The penetration phenomena at the nanometer, micrometer, or larger scale through wood cell lumens, interconnecting pits of the wood cells, and the nanovoids with cell walls has been observed by optical microscopy, electron microscopy, and X-ray fluorescence microscopy in the last few decades [12,13,14]. In particular, the nano-penetration of PF resin in wood cell walls has been intensively analyzed because it can provide the opportunity for cross-linking reactions between PF resins and the functional groups in wood polymers.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Phenol Formaldehyde Resin Penetration on the Quasi-Static and Dynamic Mechanics of Wood Cell Walls Using Nanoindentation

Wang

Chen

Xie³

et al. 2019

Nanomaterials

View full text Add to dashboard Cite

To evaluate the effects of phenol formaldehyde (PF) resin modification on wood cell walls, Masson pine (Pinus massoniana Lamb.) wood was impregnated with PF resin at the concentrations of 15%, 20%, 25%, and 30%, respectively. The penetration degree of PF resin into wood tracheids was quantitatively determined using confocal laser scanning microscopy (CLSM). The micromechanical properties of the control and PF-modified wood cell walls were then analyzed by the method of quasi-static nanoindentation and dynamic modulus mapping techniques. Results indicated that PF resin with low molecular weight can penetrate deeply into the wood tissues and even into the cell walls. However, the penetration degree decreased accompanying with the increase of penetration depth in wood. Both the quasi-static and dynamic mechanics of wood cell walls increased significantly after modification by the PF resin at the concentration less than 20%. The cell-wall mechanics maintained stable and even decreased as the resin concentration was increased above 20%, resulting from the increasing bulking effects such as the decreased crystallinity degree of cellulose. Furthermore, the mechanics of cell walls in the inner layer was lower than that in the outer layer of PF-modified wood.

show abstract

Section: Introductionmentioning

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Effect of Phenol Formaldehyde Resin Penetration on the Quasi-Static and Dynamic Mechanics of Wood Cell Walls Using Nanoindentation

Wang

Chen

Xie³

et al. 2019

Nanomaterials

View full text Add to dashboard Cite

show abstract

“…Phenol formaldehyde (PF) resin is a popular thermosetting agent that forms a three dimensional structure via cross-linking reactions after curing, which are extensively used in exterior grade wood-based panels for its excellent performance, including water resistance and chemical stability [13][14][15]. It has therefore been widely used to improve dimensional stability and strength and prolong the service life of wood for indoor and outdoor use [16][17][18]. To date, changes in physical, mechanical, and chemical properties of chemically modified wood have been intensively analyzed at the macro scale [19,20].…”

Section: Introductionmentioning

confidence: 99%

Multi-Scale Evaluation of the Effect of Phenol Formaldehyde Resin Impregnation on the Dimensional Stability and Mechanical Properties of Pinus Massoniana Lamb.

Wang

Chen

Xie³

et al. 2019

Forests

View full text Add to dashboard Cite

The local chemistry and mechanics of the control and phenol formaldehyde (PF) resin modified wood cell walls were analyzed to illustrate the modification mechanism of wood. Masson pine (Pinus massoniana Lamb.) is most widely distributed in the subtropical regions of China. However, the dimensional instability and low strength of the wood limits its use. Thus, the wood was modified by PF resin at concentrations of 15%, 20%, 25%, and 30%, respectively. The density, surface morphology, chemical structure, cell wall mechanics, shrinking and swelling properties, and macro-mechanical properties of Masson pine wood were analyzed to evaluate the modification effectiveness. The morphology and Raman spectra changes indicated that PF resin not only filled in the cell lumens, but also penetrated into cell walls and interacted with cell wall polymers. The filling and diffusing of resin in wood resulted in improved dimensional stability, such as lower swelling and shrinking coefficients, an increase in the elastic modulus (Er) and hardness (H) of wood cell walls, the hardness of the transverse section and compressive strength of the wood. Both the dimensional stability and mechanical properties improved as the PF concentration increased to 20%; that is, a PF concentration of 20% may be preferred to modify Masson pine wood.

show abstract

“…One reason for the strong influence of Phenol1 on the elasto-mechanical properties already at a low concentration could be its low molecular weight compared to Phenol2 and MF. This enables the resin to penetrate into the cell wall through nano-pores, whereas only a fraction of those modification systems with a higher molecular weight was able to enter the cell wall [15,16,20,35,36]. However, at a concentration of 0.5%, even if the modification system penetrated the cell wall completely, a reduction as strong as measured in this study was probably not solely due to the modification agent.…”

Section: Influence Of Modification Agentsmentioning

confidence: 48%

“…Alike modification with MF-resins, tensile strength of wood modified with PF-resins also exhibits a lower tensile strength [14]. Furuno, Imamura, and Kajita [15] as well as [16] examined the influence of the molecular weight of the PF-resin on its ability to penetrate the wooden cell wall using microscopy. They stated that, with an increase of the molecular weight, a higher share of the resins remained in the cell wall lumen.…”

Section: Introductionmentioning

confidence: 99%

Tensile and Impact Bending Properties of Chemically Modified Scots Pine

Bollmus¹,

Beeretz²,

Militz³

2020

Forests

Self Cite

View full text Add to dashboard Cite

This study deals with the influence of chemical modification on elasto-mechanical properties of Scots pine (Pinus sylvestris L.). The elasto-mechanical properties examined were impact bending strength, determined by impact bending test; tensile strength; and work to maximum load in traction, determined by tensile tests. The modification agents used were one melamine-formaldehyde resin (MF), one low molecular weight phenol-formaldehyde resin, one higher molecular weight phenol-formaldehyde resin, and a dimethylol dihydroxyethyleneurea (DMDHEU). Special attention was paid to the influence of the solution concentration (0.5%, 5%, and 20%). With an increase in the concentration of each modification agent, the elasto-mechanical properties decreased as compared to the control specimens. Especially impact bending strength decreased greatly by modifications with the 0.5% solutions of each agent (by 37% to 47%). Modification with DMDHEU resulted in the highest overall reduction of the elasto-mechanical properties examined (up to 81% in work to maximum load in traction at 20% solution concentration). The results indicate that embrittlement is not primarily related to the degree of modification depended on used solution concentration. It is therefore assumed that molecular size and the resulting ability to penetrate into the cell wall could be crucial. The results show that, in the application of chemically modified wood, impact and tensile loads should be avoided even after treatment with low concentrations.

show abstract

Penetration depth of phenol-formaldehyde (PF) resin into beech wood studied by light microscopy

Cited by 42 publications

References 8 publications

Effect of Phenol Formaldehyde Resin Penetration on the Quasi-Static and Dynamic Mechanics of Wood Cell Walls Using Nanoindentation

Effect of Phenol Formaldehyde Resin Penetration on the Quasi-Static and Dynamic Mechanics of Wood Cell Walls Using Nanoindentation

Multi-Scale Evaluation of the Effect of Phenol Formaldehyde Resin Impregnation on the Dimensional Stability and Mechanical Properties of Pinus Massoniana Lamb.

Tensile and Impact Bending Properties of Chemically Modified Scots Pine

Contact Info

Product

Resources

About