Tensile and Impact Bending Properties of Chemically Modified Scots Pine

Forests

Cara Beeretz¹  Holger Militz²  Susanne Bollmus² 

[1] D-37077 Goettingen, Germany;Wood Biology and Wood Products, University of Goettingen, Buesgenweg 4;

关键词: wood modification;    melamine-formaldehyde resin;    phenol-formaldehyde resin;    dmdheu;    impact bending strength;    tensile strength;   

DOI  :  10.3390/f11010084

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown